Arquivo de Electronic Circuits - Electronic Circuits https://www.elcircuits.com/category/electronic-circuits/ Circuits, tips, projects, and electronics tutorials for beginners and enthusiasts. Sat, 20 Dec 2025 19:27:06 +0000 en-US hourly 1 https://wordpress.org/?v=6.9.1 https://www.elcircuits.com/wp-content/uploads/2025/11/cropped-LOGO-ELC-500x500px-elcircuits.com_-1-32x32.png Arquivo de Electronic Circuits - Electronic Circuits https://www.elcircuits.com/category/electronic-circuits/ 32 32 How to Build a 10-LED VU Meter with Transistors – Complete Guide + PCB https://www.elcircuits.com/10-led-vu-meter-transistor/ https://www.elcircuits.com/10-led-vu-meter-transistor/#respond Sun, 30 Nov 2025 13:01:28 +0000 https://elcircuits.com/?p=2562 10 LED VU Meter with Transistors – Complete Guide + PCB 🌐 You can read this article in: Português | Español 👋 Hello, electronics enthusiast! Welcome to this complete guide where you will learn step by step how to assemble a 10 LED VU Meter using transistors. This project is perfect for audio hobbyists, home DJs, and electronics lovers who want to add an impressive visual touch to their sound projects! By the end of this tutorial, you will have an analog volume indicator that dances in rhythm with your music, transforming any sound into a visual spectacle of lights. And don’t forget to share your project on social media using the hashtag #MyVUMeter to inspire other makers! 🔍 Transistors vs. Integrated Circuits: Which is the Better Option? Before diving into the project, let’s understand why someone would choose to build a VU Meter with transistors instead of using an integrated circuit (IC) like the popular LM3915. Both approaches have their advantages, and the ideal choice depends on your experience level, component availability, and project goals. ✅ Advantages of Transistors Availability: Found in any electronics store Cost-effective: Cheaper components, even when using several Easy maintenance: If a transistor burns out, simply replace only that stage Learning: Excellent for understanding how analog circuits work ✅ Advantages of IC (LM3915) Simplified assembly: Fewer external components needed Practical maintenance: Only the IC needs to be replaced in case of failure Compact design: Ideal for projects with limited space Technical perfection: More linear and precise response to audio levels 🔌 Circuit Diagram The schematic diagram of the electronic circuit is illustrated in Figure 2 below. This is an elegant and functional circuit with transistors, which, despite having a larger number of components compared to IC-based circuits, uses only the essential elements for its operation. Fig.2 – Schematic Diagram of 10 LED VU Meter Circuit with Transistors For assembling the electronic circuit, it is essential to connect it to a 12V power supply. After the power supply is correctly installed, the VU meter input should be connected to the audio amplifier output. This type of project is ideal for those seeking to understand more about analog electronics, using transistors in practical applications such as audio level meters. It’s like having a small spectrum of lights that “dances” according to the sound intensity! 🛠️ Required Components Before we begin, let’s organize our workbench with all the necessary components. Having everything at hand makes the assembly process smoother and more enjoyable. Component Quantity Function in Circuit BC547 Transistor 10 Current amplification for LEDs 1N4148 Diode 10 Cut-off voltage scaling (0.6V) LED (any color) 10 Visual indication of audio level 10kΩ Potentiometer 1 Adjustment of input signal level 4.7kΩ Resistors 10 Transistor base biasing 12V DC Power Supply 1 Circuit power supply Printed Circuit Board (PCB) 1 Physical support for assembly ⚠️ Important note: Adjust the resistor values according to the current of the chosen LEDs. High brightness LEDs may require resistors of different values for proper operation. 💡 Fresh Ideas for Your Next Project Did you enjoy this project? Then you’ll love exploring other circuits we’ve prepared. Each one with its unique features and ideal applications! Build a Pro 10-LED VU Meter with LM3915: Ultimate DIY Guide + PCB 🔬 How the Transistor VU Meter Works The operation of the analog VU Meter is a true lesson in electronics in practice! It is based on amplifying the audio signal using bipolar transistors in an ingenious configuration. Let’s understand this process step by step: The audio signal arrives through the potentiometer P1, which functions as a “volume control” for our VU Meter. It adjusts and limits the input voltage in the circuit, allowing the device to work correctly with different audio signal levels. This adjustment should be made according to the power of your audio amplifier, ensuring accurate reading of sound levels. For the signal to act progressively on each of the transistors, from Q1 to Q10, biasing resistors are used connected between the transistors’ base and the signal input line. These resistors control the base bias current, allowing the collector current to increase in a controlled manner as the signal voltage rises. The real magic happens with the silicon diodes! Each diode has a cut-off voltage of approximately 0.6V and they are connected in series. This means that as the audio signal exceeds each multiple of 0.6V, it sequentially activates the transistors and lights up the indicator LEDs. It’s like an electrical ladder where each step is activated when the energy (voltage) reaches a specific level: With 0.6V, the first LED lights up; With 1.2V, the second LED; With 1.8V, the third LED; And so on, until the last stage of the circuit. This cascade behavior allows visualizing the audio intensity level in a clear and intuitive way, making the VU Meter an excellent tool for visual monitoring of sound signal. It’s almost like translating music into a visual language that our eyes can appreciate! 🔧 Step-by-Step Assembly Now that we understand the theory, let’s get our hands dirty! Follow these steps carefully to ensure your VU Meter works perfectly: Prepare the PCB: Print the PCB PDF and transfer it to the blank board using your preferred method (thermal transfer, laser printing, etc.). Etching and cleaning: Carefully etch the board and clean the traces well after the process. Component assembly: Start by soldering the resistors first (they are the lowest components), then the diodes and transistors. Respect the polarity of the diodes and the pinout of the transistors! Install the LEDs: Solder the LEDs, maintaining uniform spacing. Remember to respect the polarity (longer anode, shorter cathode). Mount the potentiometer: Install the potentiometer P1 in an accessible location for future adjustments. Power connections: Connect the 12V DC power supply, carefully observing the positive and negative polarity. Audio connection: Connect the audio output of your amplifier to P1. Use shielded cables to avoid interference. Initial test: Turn on the power and test by slowly increasing the volume to

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10 LED VU Meter with Transistors – Complete Guide + PCB - elcircuits.com
10 LED VU Meter with Transistors - Complete Guide + PCB

🌐 You can read this article in: Português | Español

👋 Hello, electronics enthusiast!

Welcome to this complete guide where you will learn step by step how to assemble a 10 LED VU Meter using transistors. This project is perfect for audio hobbyists, home DJs, and electronics lovers who want to add an impressive visual touch to their sound projects!

By the end of this tutorial, you will have an analog volume indicator that dances in rhythm with your music, transforming any sound into a visual spectacle of lights. And don't forget to share your project on social media using the hashtag #MyVUMeter to inspire other makers!

🔍 Transistors vs. Integrated Circuits: Which is the Better Option?

Before diving into the project, let's understand why someone would choose to build a VU Meter with transistors instead of using an integrated circuit (IC) like the popular LM3915. Both approaches have their advantages, and the ideal choice depends on your experience level, component availability, and project goals.

✅ Advantages of Transistors

  • Availability: Found in any electronics store
  • Cost-effective: Cheaper components, even when using several
  • Easy maintenance: If a transistor burns out, simply replace only that stage
  • Learning: Excellent for understanding how analog circuits work

✅ Advantages of IC (LM3915)

  • Simplified assembly: Fewer external components needed
  • Practical maintenance: Only the IC needs to be replaced in case of failure
  • Compact design: Ideal for projects with limited space
  • Technical perfection: More linear and precise response to audio levels

🔌 Circuit Diagram

The schematic diagram of the electronic circuit is illustrated in Figure 2 below. This is an elegant and functional circuit with transistors, which, despite having a larger number of components compared to IC-based circuits, uses only the essential elements for its operation.

Schematic Diagram of 10 LED VU Meter Circuit with Transistors - elcircuits.com
Fig.2 - Schematic Diagram of 10 LED VU Meter Circuit with Transistors

For assembling the electronic circuit, it is essential to connect it to a 12V power supply. After the power supply is correctly installed, the VU meter input should be connected to the audio amplifier output.

This type of project is ideal for those seeking to understand more about analog electronics, using transistors in practical applications such as audio level meters. It's like having a small spectrum of lights that "dances" according to the sound intensity!

🛠️ Required Components

Before we begin, let's organize our workbench with all the necessary components. Having everything at hand makes the assembly process smoother and more enjoyable.

Component Quantity Function in Circuit
BC547 Transistor 10 Current amplification for LEDs
1N4148 Diode 10 Cut-off voltage scaling (0.6V)
LED (any color) 10 Visual indication of audio level
10kΩ Potentiometer 1 Adjustment of input signal level
4.7kΩ Resistors 10 Transistor base biasing
12V DC Power Supply 1 Circuit power supply
Printed Circuit Board (PCB) 1 Physical support for assembly

⚠️ Important note: Adjust the resistor values according to the current of the chosen LEDs. High brightness LEDs may require resistors of different values for proper operation.

💡 Fresh Ideas for Your Next Project

Did you enjoy this project? Then you'll love exploring other circuits we've prepared. Each one with its unique features and ideal applications!

🔬 How the Transistor VU Meter Works

The operation of the analog VU Meter is a true lesson in electronics in practice! It is based on amplifying the audio signal using bipolar transistors in an ingenious configuration. Let's understand this process step by step:

The audio signal arrives through the potentiometer P1, which functions as a "volume control" for our VU Meter. It adjusts and limits the input voltage in the circuit, allowing the device to work correctly with different audio signal levels. This adjustment should be made according to the power of your audio amplifier, ensuring accurate reading of sound levels.

For the signal to act progressively on each of the transistors, from Q1 to Q10, biasing resistors are used connected between the transistors' base and the signal input line. These resistors control the base bias current, allowing the collector current to increase in a controlled manner as the signal voltage rises.

The real magic happens with the silicon diodes! Each diode has a cut-off voltage of approximately 0.6V and they are connected in series. This means that as the audio signal exceeds each multiple of 0.6V, it sequentially activates the transistors and lights up the indicator LEDs. It's like an electrical ladder where each step is activated when the energy (voltage) reaches a specific level:

  • With 0.6V, the first LED lights up;
  • With 1.2V, the second LED;
  • With 1.8V, the third LED;
  • And so on, until the last stage of the circuit.

This cascade behavior allows visualizing the audio intensity level in a clear and intuitive way, making the VU Meter an excellent tool for visual monitoring of sound signal. It's almost like translating music into a visual language that our eyes can appreciate!

🔧 Step-by-Step Assembly

Now that we understand the theory, let's get our hands dirty! Follow these steps carefully to ensure your VU Meter works perfectly:

  1. Prepare the PCB: Print the PCB PDF and transfer it to the blank board using your preferred method (thermal transfer, laser printing, etc.).
  2. Etching and cleaning: Carefully etch the board and clean the traces well after the process.
  3. Component assembly: Start by soldering the resistors first (they are the lowest components), then the diodes and transistors. Respect the polarity of the diodes and the pinout of the transistors!
  4. Install the LEDs: Solder the LEDs, maintaining uniform spacing. Remember to respect the polarity (longer anode, shorter cathode).
  5. Mount the potentiometer: Install the potentiometer P1 in an accessible location for future adjustments.
  6. Power connections: Connect the 12V DC power supply, carefully observing the positive and negative polarity.
  7. Audio connection: Connect the audio output of your amplifier to P1. Use shielded cables to avoid interference.
  8. Initial test: Turn on the power and test by slowly increasing the volume to adjust P1. The LEDs should light up progressively as the volume increases.
  9. Fine adjustment: Adjust P1 so that the LEDs respond appropriately to the maximum audio level without saturating.
  10. Finalization: Organize the cables, mount the circuit in a case or panel, and you're done!

💡 Professional tip: Use a stabilized power supply to avoid fluctuations that might cause incorrect readings on the VU Meter. Additionally, consider adding a 100µF capacitor at the power input to filter noise.

🖨️ The Printed Circuit Board (PCB)

To make your life easier, we've made the PCB available in PDF, GERBER and PNG for free download via the secure "MEGA" server. Just click on the link below:

PCB 10 LED VU Meter with Transistors - elcircuits.com
Fig. 3 - PCB 10 LED VU Meter with Transistors

🔧 Assembly tip: Use quality solder and keep the traces clean to avoid short circuits. A tip is to use a magnifying glass to inspect the solder joints after the process, ensuring there are no unwanted connections between adjacent traces.

📥 Direct Download Link

To download the necessary files for assembling the electronic circuit, simply click on the direct link provided below:

🤔 Frequently Asked Questions (FAQ)

To ensure your project is a success, we've compiled some of the most common questions about this topic. Check them out!

Can I use LEDs of different colors in my VU Meter? 🔽

Yes! You can use LEDs of different colors to create interesting visual effects. For example, green LEDs for low levels, yellow for medium, and red for high levels. Just remember that different colored LEDs may have slightly different operating voltages, which may require adjustment in the current limiting resistors.

Is it possible to modify the circuit to use more than 10 LEDs? 🔽

Yes, it's possible to expand the circuit by adding more transistor and diode stages. Each additional stage requires a transistor, a diode, and a bias resistor. However, remember that each diode adds approximately 0.6V of cut-off voltage, so you'll need to ensure your audio signal has sufficient amplitude to light up all the LEDs.

Why isn't my VU Meter responding properly to the audio signal? 🔽

This can happen for several reasons: 1) The potentiometer P1 may be poorly adjusted - try calibrating it again; 2) The audio signal may be too weak - check if the audio source is working correctly; 3) There may be problems with connections or solder joints - inspect the circuit for cold solder joints or loose connections; 4) The power supply may not be providing stable 12V - measure the voltage with a multimeter.

Can I power the circuit with a battery? 🔽

Yes, you can use a 12V battery, such as a lithium battery or a lead-acid battery. However, remember that current consumption will depend on the number of LEDs lit simultaneously. For prolonged use, consider using a higher capacity battery or adding a voltage regulator to ensure stable power supply.

How do I adjust the sensitivity of the VU Meter? 🔽

The sensitivity of the VU Meter is adjusted mainly through the potentiometer P1. Turn it clockwise to increase sensitivity (making the LEDs light up with lower volumes) or counterclockwise to decrease sensitivity. For finer adjustments, you can modify the value of the bias resistors: higher values will decrease sensitivity, while lower values will increase it.

💡 Ideas to Customize Your VU Meter

Now that you have your VU Meter working, how about adding a personal touch to your project? Here are some ideas to inspire your creativity:

🌈 Color Variation

Use LEDs of different colors to create an interesting visual gradient, such as green for low levels, yellow for medium, and red for volume peaks.

🎨 Custom Panel

Create a custom front panel with 3D printing or laser-cut acrylic to give a professional finish to your project.

💡 Dot/Bar Mode

Add a switch to toggle between "bar" mode (where all LEDs up to the current level stay on) and "dot" mode (where only the LED corresponding to the current level stays on).

🔊 Dual VU Meter

Build two identical circuits to create a stereo VU Meter, with a set of LEDs for each audio channel (left and right).

✨ Our Gratitude and Next Steps

We sincerely hope this guide has been useful and enriching for your projects! Thank you for dedicating your time to this content.

Your Feedback is Invaluable:

Have any questions, suggestions, or corrections? Feel free to share them in the comments below! Your contribution helps us refine this content for the entire ElCircuits community.

If you found this guide helpful, spread the knowledge!

🔗 Share This Guide

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]]> https://www.elcircuits.com/10-led-vu-meter-transistor/feed/ 0 Adjustable Bench Power Supply 1.25V–33V 6A Module Tutorial https://www.elcircuits.com/adjustable-bench-power-supply-1v25-33v-6a/ https://www.elcircuits.com/adjustable-bench-power-supply-1v25-33v-6a/#respond Tue, 21 Oct 2025 16:47:00 +0000 https://elcircuits.com/simple-module-for-adjustable-bench-power-supply-1-25v-to-33v-6a/ Complete module for 6A adjustable bench power supply 🌐 You can read this article in: Português | Español Hello electronics enthusiasts! Whether you’re an engineer, electronics technician, designer, or hobbyist, an adjustable bench power supply is an indispensable tool in any workspace. The problem? Quality commercial power supplies tend to be expensive and, often, limited in current. But what if I told you that you can build your own robust bench power supply with 6 amperes of current and adjustable voltage from 1.25V to 33V for a fraction of the cost? Keep reading to find out how! 🧐 Why Build Your Own Bench Power Supply? Professional bench power supplies are essential for testing and developing electronic projects, but the market offers options with two main limitations: low maximum current and high prices. Quality models easily exceed R$500.00, making them inaccessible for many students and enthusiasts. This is exactly where our project shines! We’ve developed a fantastic module that offers: Adjustable voltage: 1.25V to 33V Robust current: Up to 6 continuous amperes Short-circuit protection Thermal protection Affordable cost and easy-to-find materials 📝 Required Materials To build this adjustable bench power supply, we’ll use components that are easy to acquire and affordable. Many of them can be salvaged from old ATX power supplies! Fig. 2 – Materials needed for the voltage regulator circuit Component List: 2x LM350 ICs – 3A voltage regulators each 2x 220Ω Resistors (colors: Red, Red, Brown) 1x 5KΩ Potentiometer (preferably multi-turn for greater precision) 1x SCHOTTKY S16C45C Barrier Rectifier (16A) or alternatives 1x Universal printed circuit board or perfboard Heat sink (can be salvaged from an ATX power supply) Thermal insulators for ICs and rectifier 💡 Expert Tip: Don’t have a S16C45C rectifier? No problem! You can replace it with two common diodes, connecting anodes to the output of each LM and joining the cathodes to form a single output, as shown in the schematic. 🛠️ Step-by-Step Assembly Now that we have all the components in hand, let’s start the assembly! Follow each step carefully to ensure the correct and safe operation of your module. Step 1: Component Preparation Start by mounting the two LM350 ICs and the SCHOTTKY rectifier on the heat sink. Attention: Don’t forget to use thermal insulators between each component and the heat sink to avoid short circuits! Fig. 3 – Components mounted on heat sink with thermal insulators Step 2: Board Assembly With the components already mounted on the heat sink, fit them onto the printed circuit board. Follow the schematic to make the correct connections. The layout of components can be adapted according to your preference, as long as you maintain the correct connections. Step 3: Resistor Connection Solder the two 220Ω resistors as indicated in the schematic. They are essential for the correct operation of the regulator circuit. Fig. 4 – Schematic Diagram Adjustable Power Supply Module 1.25V to 33V, 6A Step 4: Potentiometer Installation The voltage control potentiometer will not be soldered directly to the board. Instead, we recommend installing it remotely on the front panel of your power supply. To facilitate assembly and disassembly, we’ll use a two-pin connector. 💡 Expert Tip: For greater precision in voltage adjustment, consider using a multi-turn potentiometer. They allow for finer adjustments, essential for applications that require specific voltages. Step 5: Soldering Connections With all components properly positioned, proceed with soldering all connections. Make sure there are no solder bridges or cold joints that could compromise the circuit’s operation. Fig. 5 – Soldering all connections on the universal board Step 6: Remote Potentiometer Connection Use a cable with a two-pin male connector to connect the potentiometer. This will facilitate the final assembly of your bench power supply, allowing the potentiometer to be installed on the front panel while the regulator module remains inside. Fig. 6 – Cable with connector for remote potentiometer connection 🏋️‍♀️ Want More Power? Expand to 12 Amperes! For those who think 6A is still not enough, we have excellent news! With a simple modification, it’s possible to double the current capacity to an impressive 12 amperes. The secret? Simply build two identical modules to this one and connect them in parallel. This way, you’ll have an extremely powerful bench power supply, maintaining all protections (short-circuit and thermal) and precise voltage regulation. ⚠️ Safety Warning: When working with high currents like 12A, make sure to use appropriate wires and connectors for this capacity. High currents generate more heat and require greater care with thermal dissipation. 💡 Testing and Validation Before powering your module, it’s essential to perform some safety checks: Confirm that the ICs and rectifier are properly insulated from the heat sink Check for short circuits on the board traces Test the continuity of the main connections With everything verified, let’s connect a power supply. In our example, we used a 24V supply. Remember that the maximum output voltage will be limited by the input voltage minus the voltage drop across the components (approximately 1.95V). Load Test To validate our module under real conditions, we used as a load a car headlight halogen lamp (55W, 12V). According to Ohm’s Law, this lamp consumes approximately 4.58A (55W ÷ 12V). Fig. 7 – Initial test with Halogen lamp as load We adjusted the voltage to 13.52V (typical voltage of a car with an alternator running) and connected the load. The result? Excellent stability, with a voltage drop of only 0.4V under a load of 4.58A! Fig. 8 – Load test with 55W halogen lamp 🔗 Related Content If you liked this project, you might also be interested in these other articles: Adjustable Power Supply 1.25v to 57V, 6 Amps with TIP36C + LM317HV + PCB Adjustable Power Supply 1.25v to 33V, 3 Amps with LM350 + PCB Stabilized Power Supply 13.8V High Current 10 Amps with PCB Adjustable Power Supply 1.2V to 37V High Current 20A with LM317 and TIP35C + PCB Switched Power Supply SMPS 13.8V 10A using IR2153 IC and IRF840, with PCB Adjustable Power Supply 1.2V to

O post Adjustable Bench Power Supply 1.25V–33V 6A Module Tutorial apareceu primeiro em Electronic Circuits.

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Complete module for 6A adjustable bench power supply

Complete module for 6A adjustable bench power supply

🌐 You can read this article in: Português | Español

Hello electronics enthusiasts!

Whether you’re an engineer, electronics technician, designer, or hobbyist, an adjustable bench power supply is an indispensable tool in any workspace. The problem? Quality commercial power supplies tend to be expensive and, often, limited in current. But what if I told you that you can build your own robust bench power supply with 6 amperes of current and adjustable voltage from 1.25V to 33V for a fraction of the cost? Keep reading to find out how!

🧐 Why Build Your Own Bench Power Supply?

Professional bench power supplies are essential for testing and developing electronic projects, but the market offers options with two main limitations: low maximum current and high prices. Quality models easily exceed R$500.00, making them inaccessible for many students and enthusiasts.

This is exactly where our project shines! We’ve developed a fantastic module that offers:

  • Adjustable voltage: 1.25V to 33V
  • Robust current: Up to 6 continuous amperes
  • Short-circuit protection
  • Thermal protection
  • Affordable cost and easy-to-find materials

📝 Required Materials

To build this adjustable bench power supply, we’ll use components that are easy to acquire and affordable. Many of them can be salvaged from old ATX power supplies!

Materials needed for the voltage regulator circuit

Fig. 2 – Materials needed for the voltage regulator circuit

Component List:

  • 2x LM350 ICs – 3A voltage regulators each
  • 2x 220Ω Resistors (colors: Red, Red, Brown)
  • 1x 5KΩ Potentiometer (preferably multi-turn for greater precision)
  • 1x SCHOTTKY S16C45C Barrier Rectifier (16A) or alternatives
  • 1x Universal printed circuit board or perfboard
  • Heat sink (can be salvaged from an ATX power supply)
  • Thermal insulators for ICs and rectifier

💡 Expert Tip: Don’t have a S16C45C rectifier? No problem! You can replace it with two common diodes, connecting anodes to the output of each LM and joining the cathodes to form a single output, as shown in the schematic.

🛠️ Step-by-Step Assembly

Now that we have all the components in hand, let’s start the assembly! Follow each step carefully to ensure the correct and safe operation of your module.

Step 1: Component Preparation

Start by mounting the two LM350 ICs and the SCHOTTKY rectifier on the heat sink. Attention: Don’t forget to use thermal insulators between each component and the heat sink to avoid short circuits!

Components mounted on heat sink with thermal insulators

Fig. 3 – Components mounted on heat sink with thermal insulators

Step 2: Board Assembly

With the components already mounted on the heat sink, fit them onto the printed circuit board. Follow the schematic to make the correct connections. The layout of components can be adapted according to your preference, as long as you maintain the correct connections.

Step 3: Resistor Connection

Solder the two 220Ω resistors as indicated in the schematic. They are essential for the correct operation of the regulator circuit.

Schematic Diagram Adjustable Power Supply Module 1.25V to 33V, 6A

Fig. 4 – Schematic Diagram Adjustable Power Supply Module 1.25V to 33V, 6A

Step 4: Potentiometer Installation

The voltage control potentiometer will not be soldered directly to the board. Instead, we recommend installing it remotely on the front panel of your power supply. To facilitate assembly and disassembly, we’ll use a two-pin connector.

💡 Expert Tip: For greater precision in voltage adjustment, consider using a multi-turn potentiometer. They allow for finer adjustments, essential for applications that require specific voltages.

Step 5: Soldering Connections

With all components properly positioned, proceed with soldering all connections. Make sure there are no solder bridges or cold joints that could compromise the circuit’s operation.

Soldering all connections on the universal board

Fig. 5 – Soldering all connections on the universal board

Step 6: Remote Potentiometer Connection

Use a cable with a two-pin male connector to connect the potentiometer. This will facilitate the final assembly of your bench power supply, allowing the potentiometer to be installed on the front panel while the regulator module remains inside.

Cable with connector for remote potentiometer connection

Fig. 6 – Cable with connector for remote potentiometer connection

🏋️‍♀️ Want More Power? Expand to 12 Amperes!

For those who think 6A is still not enough, we have excellent news! With a simple modification, it’s possible to double the current capacity to an impressive 12 amperes.

The secret? Simply build two identical modules to this one and connect them in parallel. This way, you’ll have an extremely powerful bench power supply, maintaining all protections (short-circuit and thermal) and precise voltage regulation.

⚠️ Safety Warning: When working with high currents like 12A, make sure to use appropriate wires and connectors for this capacity. High currents generate more heat and require greater care with thermal dissipation.

💡 Testing and Validation

Before powering your module, it’s essential to perform some safety checks:

  1. Confirm that the ICs and rectifier are properly insulated from the heat sink
  2. Check for short circuits on the board traces
  3. Test the continuity of the main connections

With everything verified, let’s connect a power supply. In our example, we used a 24V supply. Remember that the maximum output voltage will be limited by the input voltage minus the voltage drop across the components (approximately 1.95V).

Load Test

To validate our module under real conditions, we used as a load a car headlight halogen lamp (55W, 12V). According to Ohm’s Law, this lamp consumes approximately 4.58A (55W ÷ 12V).

Initial test with Halogen lamp as load

Fig. 7 – Initial test with Halogen lamp as load

We adjusted the voltage to 13.52V (typical voltage of a car with an alternator running) and connected the load. The result? Excellent stability, with a voltage drop of only 0.4V under a load of 4.58A!

Load test with 55W halogen lamp

Fig. 8 – Load test with 55W halogen lamp

🔗 Related Content

📥 Download Files

Direct link: Download Files

🧾 Conclusion

Our 6A adjustable bench power supply project demonstrates that it’s possible to build quality equipment with low cost and high efficiency. The simplicity of the circuit, combined with the robustness of the components used, results in a reliable and versatile power supply for various applications.

Whether for testing prototypes, powering circuits during development or for use in your home laboratory, this adjustable bench power supply will certainly meet your needs with excellent performance and stability.

Detailed Video

For those who would like more details about the assembly process and testing, we’ve prepared a complete video on our YouTube channel. In it, we show each step in detail and share additional tips:

🤔 Frequently Asked Questions

We’ve gathered some of the most common questions about this project to help you:

❓ Can I use a transformer different from 24V?🔽

Yes! You can use transformers with voltages between 18V and 30V. Remember that the maximum output voltage will always be approximately 2V lower than the input voltage.

❓ Is it mandatory to use the SCHOTTKY rectifier?🔽

It’s not mandatory, but it’s recommended. SCHOTTKY rectifiers have lower voltage drop, which improves the circuit’s efficiency. You can replace it with common diodes as explained in the article.

❓ Do I need to use a specific heat sink?🔽

Not necessarily. Heat sinks from ATX power supplies are usually sufficient, but remember that the greater the dissipation, the better the performance at high currents.

❓ Can I add a digital display to show voltage and current?🔽

Absolutely! There are digital display modules with voltmeter and ammeter that can be easily integrated into this project for greater precision and convenience.

Did you like this project?

Leave your comment below sharing your questions, suggestions or experiences with bench power supplies! Your interaction helps us create more and more quality content for the electronics community.

Original article published on FVML (Portuguese) – December 13, 2018

✨ Our Gratitude and Next Steps

We sincerely hope this guide has been useful and enriching for your projects! Thank you for dedicating your time to this content.

Your Feedback is Invaluable:

Have any questions, suggestions, or corrections? Feel free to share them in the comments below! Your contribution helps us refine this content for the entire ElCircuits community.

If you found this guide helpful, spread the knowledge!

🔗 Share This Guide

Best regards,
The ElCircuits Team ⚡

O post Adjustable Bench Power Supply 1.25V–33V 6A Module Tutorial apareceu primeiro em Electronic Circuits.

]]> https://www.elcircuits.com/adjustable-bench-power-supply-1v25-33v-6a/feed/ 0 10A Variable Power Supply 1.25–35V Using LM317 and D13007 https://www.elcircuits.com/variable-power-supply-1v25-35v-10a-lm317-d13007/ https://www.elcircuits.com/variable-power-supply-1v25-35v-10a-lm317-d13007/#respond Fri, 17 Oct 2025 22:49:00 +0000 https://elcircuits.com/variable-power-supply-1-25-to-35v-10-amperes-with-d13007-transistor-and-lm317/ Variable Power Supply 1.25 to 35V 10A with Transistor D13007 and LM317 🌐 You can read this article in: Português | Español A Variable Bench Power Supply 1.25V to 35V with 13007 Transistor and LM317: Transforming Scrap into Professional Equipment Hello, electronics enthusiasts! If you’re an engineer, technician, hobbyist, or simply a “Maker” like me, you probably accumulate scrap components at home or in the laboratory. Among the most common treasures found in computer switching power supplies is a very well-known transistor in the maker world: the 13007. This transistor, designed for fast switching and with excellent collector current capacity, is perfect for our project today: a high-current bench power supply that will transform those forgotten components into an indispensable tool for your projects. 💡 Expert tip: This project demonstrates how it’s possible to reuse components from computer power supplies to create high-quality equipment, saving resources and contributing to sustainability in electronics. 📖 LM317 Voltage Regulator Specifications The LM317 is a 3-terminal adjustable positive voltage regulator capable of supplying a current of 1.5A over a wide output voltage range of 1.25 to 35 V. For our bench power supply, however, this maximum current would be limited. This is where the ingenuity of our project comes in: we’ll enhance the circuit with two transistors to create a Booster that will multiply the current capacity of the system. With this modification, we can easily deliver 10 Amperes with variable voltage between 1.25 to 37 Volts, using just two NPN transistors 13007 (or 13009, which supports up to 12A). Component Standard Specification With Modification Maximum Current 1.5A 10A Voltage Range 1.25V – 35V 1.25V – 37V Additional Component – 2x 13007 Transistors 🔌 Schematic Diagram The schematic diagram of the electrical circuit is shown in Figure 2, which shows the arrangement of each component and their connections. As you can see, the assembly is quite simple and straightforward, even for beginners in electronics. Fig 2 – Schematic Diagram Variable Power Supply 1.25 to 35V 10A ⚠️ Important note: When assembling this circuit, pay special attention to the polarity of components, especially diodes and electrolytic capacitors. An incorrect connection can permanently damage the components. 🛠️ Operation The 13007 transistors (which may have different prefixes like D13007, MJE13007, SDT13007, etc.) are configured in emitter follower mode. This means that the output voltage through the emitters will be equal to the output voltage of the LM317 IC. When you adjust the potentiometer of the LM317 to a specific voltage, the two power transistors reproduce this same voltage at their emitters. Since the collectors of these transistors are connected in parallel, forming a high-current bridge, they transform the limited capability of the LM317 (maximum of 1.5A) into a power supply capable of delivering much higher current. ✨ Educational analogy: Think of the LM317 as the “brain” that controls the voltage, while the 13007 transistors function as “muscles” that provide the necessary strength to deliver high current. Together, they form an efficient team where each component plays its ideal role. The final maximum current capacity will depend on both the transistors used and the specification of the transformer of the power supply that will power this circuit. 🌡️ The Vital Importance of the Heat Sink Thermal dissipation is one of the most critical aspects in this project. The 13007 transistors operating at high currents generate significant heat that, if not properly dissipated, can lead to catastrophic failures. Think of the heat sink as the cooling system of a high-performance engine – without it, overheating is inevitable.  Excessive heat not only reduces the lifespan of the transistors but also affects the stability of the output voltage. For continuous operations above 5A, a robust heat sink with sufficient area and, ideally, forced ventilation is indispensable.  Don’t skimp on this component! Investing in a good thermal dissipation system, including quality thermal paste, is the difference between a reliable power supply and a frustrating project. Remember: in power electronics, heat is the number one enemy of your project’s longevity. 🧾 Complete Bill of Materials To build this high-current bench power supply, you will need the following components. We’ve organized the list clearly to facilitate your purchase or inventory check: Component Specification Notes IC LM317 Adjustable voltage regulator T1, T2 MJE13007 NPN power transistors D1, D2 1N4007 Rectifier diodes C1 4700 uF – 63V Main filter electrolytic capacitor C2 10 uF – 63V Stabilization electrolytic capacitor C3 47 uF – 63V Output electrolytic capacitor R1 220 ohms Resistor (red, red, brown) R2, R3 0.22 ohms – 5W Power resistors (red, red, gold) P1 4.7 k ohms Linear or logarithmic potentiometer B1, B2 2-way terminal blocks Solderable type for input and output Others Wires, Solder, etc. Basic assembly material 💡 Expert tip: If you can’t find the 13007 transistor, you can replace it with the 13009, which supports up to 12A of collector current. This will give you an even greater safety margin for your power supply. 🔧 Couldn’t find the 13007 transistor? Don’t worry! We offer an exclusive tool for Transistor Substitution by Data Cross-Reference that helps you find compatible alternatives. Just access our substitution tool, enter the transistor code and get a list of direct substitutes and equivalents that will work perfectly in this circuit. 💡 Assembly and Safety Tips To ensure the correct and safe operation of your bench power supply, follow these important recommendations: ⚠️ Essential Precautions Heat dissipation: The 13007 transistors must be mounted on a good heat sink, as they will operate with high currents and generate significant heat. Consider using thermal paste to improve heat transfer. Isolation: If the transistors are mounted on the same heat sink, use mica insulators to prevent short circuits between the collectors. Ventilation: For continuous operations at high current, consider adding a small fan to assist in cooling the components. Adequate transformer: Use a transformer with current capacity compatible with your needs (minimum 10A to take full advantage of the circuit’s potential). 🔍 Circuit Testing and Adjustment After assembling the circuit,

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Variable Power Supply 1.25 to 35V 10A with Transistor D13007 and LM317 - elcircuits.com

Variable Power Supply 1.25 to 35V 10A with Transistor D13007 and LM317

🌐 You can read this article in: Português | Español

A Variable Bench Power Supply 1.25V to 35V with 13007 Transistor and LM317: Transforming Scrap into Professional Equipment

Hello, electronics enthusiasts!

If you’re an engineer, technician, hobbyist, or simply a “Maker” like me, you probably accumulate scrap components at home or in the laboratory. Among the most common treasures found in computer switching power supplies is a very well-known transistor in the maker world: the 13007.

This transistor, designed for fast switching and with excellent collector current capacity, is perfect for our project today: a high-current bench power supply that will transform those forgotten components into an indispensable tool for your projects.

💡 Expert tip: This project demonstrates how it’s possible to reuse components from computer power supplies to create high-quality equipment, saving resources and contributing to sustainability in electronics.

📖 LM317 Voltage Regulator Specifications

The LM317 is a 3-terminal adjustable positive voltage regulator capable of supplying a current of 1.5A over a wide output voltage range of 1.25 to 35 V.

For our bench power supply, however, this maximum current would be limited. This is where the ingenuity of our project comes in: we’ll enhance the circuit with two transistors to create a Booster that will multiply the current capacity of the system.

With this modification, we can easily deliver 10 Amperes with variable voltage between 1.25 to 37 Volts, using just two NPN transistors 13007 (or 13009, which supports up to 12A).

Component Standard Specification With Modification
Maximum Current 1.5A 10A
Voltage Range 1.25V – 35V 1.25V – 37V
Additional Component – 2x 13007 Transistors

🔌 Schematic Diagram

The schematic diagram of the electrical circuit is shown in Figure 2, which shows the arrangement of each component and their connections. As you can see, the assembly is quite simple and straightforward, even for beginners in electronics.

Schematic Diagram Variable Power Supply 1.25 to 35V 10A - elcircuits.com

Fig 2 – Schematic Diagram Variable Power Supply 1.25 to 35V 10A

⚠️ Important note: When assembling this circuit, pay special attention to the polarity of components, especially diodes and electrolytic capacitors. An incorrect connection can permanently damage the components.

🛠️ Operation

The 13007 transistors (which may have different prefixes like D13007, MJE13007, SDT13007, etc.) are configured in emitter follower mode. This means that the output voltage through the emitters will be equal to the output voltage of the LM317 IC.

When you adjust the potentiometer of the LM317 to a specific voltage, the two power transistors reproduce this same voltage at their emitters. Since the collectors of these transistors are connected in parallel, forming a high-current bridge, they transform the limited capability of the LM317 (maximum of 1.5A) into a power supply capable of delivering much higher current.

✨ Educational analogy: Think of the LM317 as the “brain” that controls the voltage, while the 13007 transistors function as “muscles” that provide the necessary strength to deliver high current. Together, they form an efficient team where each component plays its ideal role.

The final maximum current capacity will depend on both the transistors used and the specification of the transformer of the power supply that will power this circuit.

🌡️ The Vital Importance of the Heat Sink

Thermal dissipation is one of the most critical aspects in this project. The 13007 transistors operating at high currents generate significant heat that, if not properly dissipated, can lead to catastrophic failures. Think of the heat sink as the cooling system of a high-performance engine – without it, overheating is inevitable. 

Excessive heat not only reduces the lifespan of the transistors but also affects the stability of the output voltage. For continuous operations above 5A, a robust heat sink with sufficient area and, ideally, forced ventilation is indispensable. 

Don’t skimp on this component! Investing in a good thermal dissipation system, including quality thermal paste, is the difference between a reliable power supply and a frustrating project. Remember: in power electronics, heat is the number one enemy of your project’s longevity.

🧾 Complete Bill of Materials

To build this high-current bench power supply, you will need the following components. We’ve organized the list clearly to facilitate your purchase or inventory check:

Component Specification Notes
IC LM317 Adjustable voltage regulator
T1, T2 MJE13007 NPN power transistors
D1, D2 1N4007 Rectifier diodes
C1 4700 uF – 63V Main filter electrolytic capacitor
C2 10 uF – 63V Stabilization electrolytic capacitor
C3 47 uF – 63V Output electrolytic capacitor
R1 220 ohms Resistor (red, red, brown)
R2, R3 0.22 ohms – 5W Power resistors (red, red, gold)
P1 4.7 k ohms Linear or logarithmic potentiometer
B1, B2 2-way terminal blocks Solderable type for input and output
Others Wires, Solder, etc. Basic assembly material

💡 Expert tip: If you can’t find the 13007 transistor, you can replace it with the 13009, which supports up to 12A of collector current. This will give you an even greater safety margin for your power supply.

🔧 Couldn’t find the 13007 transistor? Don’t worry! We offer an exclusive tool for Transistor Substitution by Data Cross-Reference that helps you find compatible alternatives. Just access our substitution tool, enter the transistor code and get a list of direct substitutes and equivalents that will work perfectly in this circuit.

💡 Assembly and Safety Tips

To ensure the correct and safe operation of your bench power supply, follow these important recommendations:

⚠️ Essential Precautions

  • Heat dissipation: The 13007 transistors must be mounted on a good heat sink, as they will operate with high currents and generate significant heat. Consider using thermal paste to improve heat transfer.
  • Isolation: If the transistors are mounted on the same heat sink, use mica insulators to prevent short circuits between the collectors.
  • Ventilation: For continuous operations at high current, consider adding a small fan to assist in cooling the components.
  • Adequate transformer: Use a transformer with current capacity compatible with your needs (minimum 10A to take full advantage of the circuit’s potential).

🔍 Circuit Testing and Adjustment

After assembling the circuit, follow these steps to test and adjust your power supply:

  1. Initial check: Before powering on, check all connections, especially the polarity of diodes and electrolytic capacitors.
  2. No-load test: Connect a multimeter to the output and turn the potentiometer to check if the voltage varies correctly between 1.25V and approximately 37V.
  3. Load test: Connect a resistive load (such as a lamp or power resistor) and check if the power supply maintains the regulated voltage.
  4. Temperature monitoring: During testing, monitor the temperature of the transistors and the LM317. If any component heats excessively, turn off immediately and check the connections.

👉 Possible Improvements and Modifications

After building your basic power supply, you can consider these improvements to make it even more versatile:

  • Adding voltmeter and ammeter: Install digital meters for direct visualization of output voltage and current.
  • Current limiting: Implement an overcurrent protection circuit to protect your projects.
  • Polarity reversal protection: Add a diode at the input to protect the circuit against incorrect connections.
  • Multiple outputs: Create fixed output terminals (such as 5V and 12V) in addition to the variable output.

🤔 Frequently Asked Questions (FAQ)

We’ve gathered some of the most common questions about this project to help you:

❓ Can I use other transistors besides the 13007?🔽

Yes! You can use transistors with similar characteristics, such as 13009, 2SC5200 or even TIP35C, as long as they are NPN and support the desired current. Always check the datasheet for compatibility. To facilitate your search, use our tool: Equivalent BJT Transistor by Data Cross-Reference, which will provide compatible alternatives based on the necessary electrical characteristics.

❓ What is the maximum power this power supply can provide?🔽

The maximum power will depend on the output voltage and the transformer used. For example, at 12V with 10A, you would have 120W. Remember that the transistors will need to dissipate the heat resulting from the difference between the input and output voltage.

❓ Is it possible to add current control?🔽

Yes, it’s possible to implement a current control circuit, but this will require more complex modifications to the original circuit. There are several online projects that show how to add this functionality.

🔗 Related Content

If you liked this project, you might also be interested in these other articles:

👋 Conclusion

With this project, you’ve transformed simple components into a professional bench power supply, capable of meeting the most demanding needs of your electronic projects. Besides saving money, you’ve developed practical skills and better understood how power supplies work.

🎉 Challenge for you: After building your power supply, share a photo in the comments or on our social media! We’d love to see your creation and how you personalized the project. If you have difficulty finding any component, remember to use our tool: Equivalent BJT Transistor by Data Cross-Reference, to find compatible alternatives.

Original article published on FVML (Portuguese) – August 12, 2019

✨ Our Gratitude and Next Steps

We sincerely hope this guide has been useful and enriching for your projects! Thank you for dedicating your time to this content.

Your Feedback is Invaluable:

Have any questions, suggestions, or corrections? Feel free to share them in the comments below! Your contribution helps us refine this content for the entire ElCircuits community.

If you found this guide helpful, spread the knowledge!

🔗 Share This Guide

Best regards,
The ElCircuits Team ⚡

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]]> https://www.elcircuits.com/variable-power-supply-1v25-35v-10a-lm317-d13007/feed/ 0 How to Build a 50W RMS MOSFET Audio Amplifier – DIY Project https://www.elcircuits.com/50w-mosfet-audio-amplifier-diy/ https://www.elcircuits.com/50w-mosfet-audio-amplifier-diy/#respond Fri, 17 Oct 2025 13:29:00 +0000 https://elcircuits.com/build-a-50w-rms-audio-amplifier-with-mosfet-complete-diy-guide/ Simple 50W RMS Audio Amplifier with Mosfet 🌐 You can read this article in: Português | Español Hello, electronics enthusiasts! Today we’re going to dive into fascinating world of audio amplifiers! Get ready to build a simple yet excellent quality Audio Amplifier with 2 Mosfet output transistors that will surprise you with its 50W RMS on an 8 ohm speaker. This project is perfect both for beginners who want to improve their skills and for hobbyists looking for an efficient amplifier with good sound quality. 🔬 Amplifier Technical Specifications Output Power 50W RMS Load Impedance 8 ohms Supply Voltage +/- 35V DC Maximum Current 2A (mono) / 4A (stereo) Output Configuration Complementary push-pull with Mosfets 👨‍🔧 How Does This 50W RMS Amplifier Work? Before we get our hands dirty, let’s understand how this circuit works. The amplifier is divided into three main stages, each with a specific function to ensure clear and powerful sound reproduction. 1️⃣ Input Stage: Differential Amplifier The first stage of amplifier is a differential amplifier based on PNP transistors BC556, Q1 and Q2. This stage is responsible for receiving low-amplitude audio signal and preparing it for following stages. The capacitor C2 functions as an input DC decoupler, ensuring that only audio signal passes through. The resistor R1 limits input current, protecting circuit, and capacitor C1 diverts unwanted high frequencies, functioning as a simple low-pass filter. 2️⃣ Driver Stage: The Heart of Amplifier The second stage is drive stage composed of transistors Q3, BC546, and transistor Q4. This section functions as a voltage amplifier, increasing the signal received from the input stage and preparing it for the output stage. Additionally, this stage aims to regulate the bias of the output transistors, ensuring they operate in their linear region and minimizing distortion. 3️⃣ Output Stage: Power and Efficiency with Mosfets The output stage is a complementary push-pull stage based on MOSFETs IRF530 and IRF9530. This configuration is ideal for power amplifiers, as one MOSFET conducts the positive half of the signal while the other conducts the negative half, resulting in high efficiency and low distortion. The output is coupled to the speaker using inductor L1, which helps to isolate the speaker from any DC component that might be present in the output signal. 💡 Expert Tip If you don’t have access to any of these specific transistors, don’t worry! We provide on our website a tool called: Equivalent BJT Transistor by Data Cross-Reference With this tool, you ensure the correct functioning of the circuit, even using components different from those suggested here. 📌 Additional Components: Stability and Quality The network composed of R15 and C5 is intended for noise reduction, functioning as a Zobel filter to stabilize the load and prevent high-frequency oscillations. The capacitors C6 and C7 are power supply filters, essential for eliminating ripple and ensuring a clean power supply for the circuit. The variable resistor R6 is a crucial component intended to adjust the quiescent current of the bias transistor, allowing optimization of the MOSFETs’ operating point for lower distortion. 🔌 50 Watt Amplifier Circuit Diagram In Figure 2 below, we have the schematic diagram of the circuit. Despite being a circuit with few components, we must pay special attention during assembly, as we are working with at least 6 transistors, diodes, and electrolytic capacitors with defined polarities. ⚠️ Attention: If any component is inverted, we can cause component burnout or even small explosions, in the case of capacitors. Always check the polarity before soldering! Fig 2 – Schematic Diagram 50W RMS Audio Amplifier with Mosfet 💡 Tips for Circuit Assembly We don’t currently have a printed circuit board, so when building your amplifier, assemble it on a good quality PCB. Here are some important tips: Use a good quality printed circuit board with thick copper to support the necessary current Keep audio signal traces as short as possible to reduce noise Separate power traces from signal traces to avoid interference Use good quality solder and check all connections before powering the circuit You might also be interested in: 160W High Fidelity Amplifier using Mosfet 2SK1058 and 2SJ162 with PCB 440W Class AB Power Amplifier using Mosfet IRFP9240 and IRFP240 with PCB 200W RMS Power Amplifier With 2SC2500 AND 2SA1943 + PCB 300W RMS Power Amplifier – 2SC3858 and 2SA1494 Transistors + PCB 50W RMS Audio Amplifier with IRF530 and IRF9530 Mosfet + PCB 100W RMS Power Amplifier With 2 NPN 2SC5200 Transistors At Output + PCB Simple 3 Transistors Power Amplifier push a 600W RMS Subwoofer + PCB 🧾 Complete Bill of Materials To facilitate your assembly, we’ve organized all necessary components in a clear and detailed table. Note everything before starting your project! Component Reference Specifications Color Code / Notes 🔌 TRANSISTORS PNP Transistor Q1, Q2 BC556 – NPN Transistor Q3, Q4 BC546 – N-Channel MOSFET Q5 IRF530 – P-Channel MOSFET Q6 IRF9530 – ⚡ DIODES Rectifier Diode D1 1N4002 (1N4001, 04, 05, 07) 🔋 CAPACITORS Ceramic/Polyester C1 220pF – Electrolytic C2, C3 47µF – 35V – Electrolytic C4 100µF – 35V – Ceramic/Polyester C5 68nF – Electrolytic C6, C7 100µF – 50V – 🔧 RESISTORS Resistor R1, R12 4.7KΩ yellow, violet, red, gold Resistor R2, R5 47KΩ yellow, violet, orange, gold Resistor R3 15KΩ brown, green, orange, gold Resistor R4 1.2KΩ brown, red, red, gold Resistor R6 1KΩ brown, black, red, gold Resistor R7 820Ω gray, red, brown, gold Resistor R8 10KΩ brown, black, orange, gold Resistor R9 680Ω blue, gray, brown, gold Resistor R10, R11 2.7KΩ red, violet, red, gold Resistor R13 560Ω green, blue, brown, gold Resistor R14 2.2KΩ red, red, red, gold Resistor (2W) R15 10Ω / 2W brown, black, black, gold 🎛️ ADDITIONAL COMPONENTS Trimpot RP1 1KΩ – Connector (2 pins) P1, P2 WJ2EDGVC-5.08-2P – Connector (3 pins) P3 WJ2EDGVC-5.08-3P – Coil L1 5µH – 10 turns 18AWG 3/8″ (1cm) core Miscellaneous – Heatsink, Wires, Solder – ⚡ Adequate Power Supply To ensure the maximum performance of your amplifier, it’s crucial to use an adequate power supply.

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Simple 50W RMS Audio Amplifier with Mosfet - elcircuits.com

Simple 50W RMS Audio Amplifier with Mosfet

🌐 You can read this article in: Português | Español

Hello, electronics enthusiasts!

Today we’re going to dive into fascinating world of audio amplifiers! Get ready to build a simple yet excellent quality Audio Amplifier with 2 Mosfet output transistors that will surprise you with its 50W RMS on an 8 ohm speaker.

This project is perfect both for beginners who want to improve their skills and for hobbyists looking for an efficient amplifier with good sound quality.

🔬 Amplifier Technical Specifications

Output Power 50W RMS
Load Impedance 8 ohms
Supply Voltage +/- 35V DC
Maximum Current 2A (mono) / 4A (stereo)
Output Configuration Complementary push-pull with Mosfets

👨‍🔧 How Does This 50W RMS Amplifier Work?

Before we get our hands dirty, let’s understand how this circuit works. The amplifier is divided into three main stages, each with a specific function to ensure clear and powerful sound reproduction.

1️⃣ Input Stage: Differential Amplifier

The first stage of amplifier is a differential amplifier based on PNP transistors BC556, Q1 and Q2. This stage is responsible for receiving low-amplitude audio signal and preparing it for following stages. The capacitor C2 functions as an input DC decoupler, ensuring that only audio signal passes through. The resistor R1 limits input current, protecting circuit, and capacitor C1 diverts unwanted high frequencies, functioning as a simple low-pass filter.

2️⃣ Driver Stage: The Heart of Amplifier

The second stage is drive stage composed of transistors Q3, BC546, and transistor Q4. This section functions as a voltage amplifier, increasing the signal received from the input stage and preparing it for the output stage. Additionally, this stage aims to regulate the bias of the output transistors, ensuring they operate in their linear region and minimizing distortion.

3️⃣ Output Stage: Power and Efficiency with Mosfets

The output stage is a complementary push-pull stage based on MOSFETs IRF530 and IRF9530. This configuration is ideal for power amplifiers, as one MOSFET conducts the positive half of the signal while the other conducts the negative half, resulting in high efficiency and low distortion. The output is coupled to the speaker using inductor L1, which helps to isolate the speaker from any DC component that might be present in the output signal.

💡 Expert Tip

If you don’t have access to any of these specific transistors, don’t worry! We provide on our website a tool called:

Equivalent BJT Transistor by Data Cross-Reference

With this tool, you ensure the correct functioning of the circuit, even using components different from those suggested here.

📌 Additional Components: Stability and Quality

The network composed of R15 and C5 is intended for noise reduction, functioning as a Zobel filter to stabilize the load and prevent high-frequency oscillations. The capacitors C6 and C7 are power supply filters, essential for eliminating ripple and ensuring a clean power supply for the circuit. The variable resistor R6 is a crucial component intended to adjust the quiescent current of the bias transistor, allowing optimization of the MOSFETs’ operating point for lower distortion.

🔌 50 Watt Amplifier Circuit Diagram

In Figure 2 below, we have the schematic diagram of the circuit. Despite being a circuit with few components, we must pay special attention during assembly, as we are working with at least 6 transistors, diodes, and electrolytic capacitors with defined polarities.

⚠️ Attention: If any component is inverted, we can cause component burnout or even small explosions, in the case of capacitors. Always check the polarity before soldering!

Schematic Diagram 50W RMS Audio Amplifier with Mosfet - elcircuits

Fig 2 – Schematic Diagram 50W RMS Audio Amplifier with Mosfet

💡 Tips for Circuit Assembly

We don’t currently have a printed circuit board, so when building your amplifier, assemble it on a good quality PCB. Here are some important tips:
  • Use a good quality printed circuit board with thick copper to support the necessary current
  • Keep audio signal traces as short as possible to reduce noise
  • Separate power traces from signal traces to avoid interference
  • Use good quality solder and check all connections before powering the circuit

🧾 Complete Bill of Materials

To facilitate your assembly, we’ve organized all necessary components in a clear and detailed table. Note everything before starting your project!
Component Reference Specifications Color Code / Notes
🔌 TRANSISTORS
PNP Transistor Q1, Q2 BC556 –
NPN Transistor Q3, Q4 BC546 –
N-Channel MOSFET Q5 IRF530 –
P-Channel MOSFET Q6 IRF9530 –
⚡ DIODES
Rectifier Diode D1 1N4002 (1N4001, 04, 05, 07)
🔋 CAPACITORS
Ceramic/Polyester C1 220pF –
Electrolytic C2, C3 47µF – 35V –
Electrolytic C4 100µF – 35V –
Ceramic/Polyester C5 68nF –
Electrolytic C6, C7 100µF – 50V –
🔧 RESISTORS
Resistor R1, R12 4.7KΩ yellow, violet, red, gold
Resistor R2, R5 47KΩ yellow, violet, orange, gold
Resistor R3 15KΩ brown, green, orange, gold
Resistor R4 1.2KΩ brown, red, red, gold
Resistor R6 1KΩ brown, black, red, gold
Resistor R7 820Ω gray, red, brown, gold
Resistor R8 10KΩ brown, black, orange, gold
Resistor R9 680Ω blue, gray, brown, gold
Resistor R10, R11 2.7KΩ red, violet, red, gold
Resistor R13 560Ω green, blue, brown, gold
Resistor R14 2.2KΩ red, red, red, gold
Resistor (2W) R15 10Ω / 2W brown, black, black, gold
🎛️ ADDITIONAL COMPONENTS
Trimpot RP1 1KΩ –
Connector (2 pins) P1, P2 WJ2EDGVC-5.08-2P –
Connector (3 pins) P3 WJ2EDGVC-5.08-3P –
Coil L1 5µH – 10 turns 18AWG 3/8″ (1cm) core
Miscellaneous – Heatsink, Wires, Solder –

⚡ Adequate Power Supply

To ensure the maximum performance of your amplifier, it’s crucial to use an adequate power supply. The required power supply is of the symmetric type +/- 35V DC, with a current of at least 2 Amperes. This voltage and current are essential for the amplifier to deliver the promised 50W RMS with low distortion.

💡 Tip for Stereo Configuration

For those who want to build a stereo amplifier, just build two identical circuits and double the power supply current to 4 Amperes. Remember that each channel will need its own set of components and heat sink!

🌀 Construction of Coil L1

For coil L1, wind 12 turns of enameled copper wire 18AWG with a diameter of 3/8″ or 1cm without a physical core. This coil is crucial to isolate the speaker from any DC component and improve the frequency response of the amplifier.

🔵 Selection of Capacitors

The electrolytic capacitors C6 and C7, which act as power supply filters, should have minimum voltages of 50V to ensure safety and durability. The other electrolytics can be 25 or 35V, as long as they respect the specified capacitance values.

📏 Essential Heat Sink

An adequate Heat Sink is necessary for MOSFETs. We recommend a heatsink with medium dimensions of 22x12x12cm with sufficient dissipation area to ensure that the transistors operate at safe temperatures, even at higher volumes. Remember to use thermal paste between the MOSFETs and heatsink for better heat transfer!

⚠️ Important Warning

Pay attention to the speaker, as the output of this amplifier is 50W RMS. Make sure your speaker can handle this power to avoid damage. Speakers with lower power can be damaged at higher volumes!

🎵 Test and Adjustment

After assembling the circuit, before connecting the speaker, adjust the trimpot RP1 to approximately the middle of its course. Connect a multimeter in series with the power supply and check if the quiescent current is between 50-100mA. Adjust RP1 as necessary to obtain this value.

🤔 Possible Problems and Solutions

If you encounter problems during the assembly or operation of the amplifier, here are some solutions to the most common problems:
Problem Possible Cause Solution
No sound at output Incorrect connections or damaged components Check all connections and test the components
Distorted sound Incorrect bias or insufficient power supply Adjust RP1 and check the power supply
MOSFETs overheating Inadequate heatsink or excessive bias Improve the heatsink or reduce the RP1 adjustment
High-frequency noise Instability or interference Check capacitor C5 and board layout

🛠️ Optional Improvements

If you want to take your amplifier to the next level, here are some improvements that can be implemented:
  • Short-circuit protection: Adding a protection circuit can prevent damage to the MOSFETs in case of a short at the output.
  • Enhanced power supply filter: Larger capacitors or addition of inductors in the power supply can further reduce noise.
  • Mute circuit: Implementing a mute circuit can prevent noise when turning the amplifier on/off.
  • Power indicator: Adding LEDs or a VU meter can give a more professional look to your project.

❓ Frequently Asked Questions (FAQ)

Find answers to common questions about this amplifier.

What is the real power of this amplifier?🔽

This amplifier delivers 50W RMS on an 8-ohm speaker, when powered with a symmetric supply of +/- 35V. This is real power (RMS), not peak power or PMPO.

Can I use other MOSFET transistors instead of IRF530 and IRF9530?🔽

Yes, you can use other MOSFETs with similar characteristics. We recommend MOSFETs with operating voltage of at least 60V and maximum current of 17A or more. Some possible substitutes are IRF540/IRF9540 or IRFZ44/IRF9Z34.

Does this amplifier need a symmetric power supply?🔽

Yes, this circuit was designed to work with a symmetric power supply of +/- 35V. Trying to use a single supply will result in incorrect operation and possibly damage to the components.

How should I adjust the trimpot RP1?🔽

The trimpot RP1 adjusts the quiescent current (bias) of the MOSFETs. Start with it in the central position and measure the quiescent current with a multimeter. The ideal is between 50-100mA. Adjust slowly until you obtain this value. A very low current can cause distortion, while a very high one can overheat the transistors.

Can I use this amplifier for subwoofers?🔽

Yes, this amplifier works well for subwoofers, but you may need to adjust the value of capacitor C1 to decrease the cutoff frequency of the input high-pass filter. A value between 470pF and 1nF would be more suitable for subwoofer applications.

Original article published on FVML (Portuguese) – August 12, 2019

✨ Our Gratitude and Next Steps

We sincerely hope this guide has been useful and enriching for your projects! Thank you for dedicating your time to this content.

Your Feedback is Invaluable:

Have any questions, suggestions, or corrections? Feel free to share them in the comments below! Your contribution helps us refine this content for the entire ElCircuits community.

If you found this guide helpful, spread the knowledge!

🔗 Share This Guide

Best regards, The ElCircuits Team ⚡

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]]> https://www.elcircuits.com/50w-mosfet-audio-amplifier-diy/feed/ 0 Mini Switching Power Supply 5V–25V 3A Using TNY268 – With PCB https://www.elcircuits.com/mini-switching-power-supply-5v-25v-3a-tny268/ https://www.elcircuits.com/mini-switching-power-supply-5v-25v-3a-tny268/#respond Fri, 14 Apr 2023 17:36:00 +0000 https://elcircuits.com/mini-switching-power-supply-5v-25v-3a-using-tny268-and-pcb/ Mini Switching Power Supply 5V – 25V, 3A with TNY268 and PCB 🌐 You can read this article in: Português|Español Compact 3A Mini Switching Power Supply: Build Your Own 5V-25V Solution with TNY268 and PCB Hello, electronics enthusiasts! In this article, we will be discussing a mini switched power supply that provides 5V to 25Vdc output. This power supply is perfect for various electronic devices that require a stable and reliable power supply. This is a power supply based on the TNY268 Integrated Circuit, which is part of a series of TinySwitch-II circuits: TNY263, TNY264, TNY265, TNY266, TNY267 and TNY268. For a Flyback-type switched power supply like the one proposed, this IC is ideal, it integrates in its encapsulation the components necessary for it to work: PWM Control, Power Mosfets Overcurrent Protection Over-Temperature Protection Self-Feeding System It does not need auxiliary windings, which makes it a complete IC, with DIP8 encapsulation, with a PWM working frequency of 132kHz and a voltage of up to 700V. We will dive into the technical specifications, design, and features of this power supply and how it compares to other similar products in the market. 📖 Technical Specifications The mini switched power supply has an input voltage range of 80V to 260V AC, which makes it suitable for use in different parts of the world. It provides an output voltage that can be regulated between 5V to 25V, with a current of up to 3A, depending on the configuration that we choose. The power supply also has short-circuit protection and overvoltage protection, ensuring the safety of the connected devices. ℹ️ Design The mini switched power supply has a compact design, with dimensions of 55mm x 26mm x 21mm. The power supply is enclosed in a plastic case that protects the circuitry from dust and other environmental factors. The power supply has a standard WJ2EDGVC-5.08-2P connector, making it easy to connect different electronic devices. ⚠️ Caution!⚠️ “This circuit works directly connected to the electrical network, this is extremely dangerous, any carelessness, or wrong connections, design error, or any other occasion, can lead to irreversible damage. We are not responsible for any type of occurrence. If you don’t have enough experience, don’t build this circuit, and if you build it, when testing it, be sure to have the proper protections and be accompanied by someone else.” 🛠️ Features One of the standout features of this mini switched power supply is its efficiency. It has a high efficiency rating of up to 85%, which means that it wastes less energy as heat compared to other similar products. This feature is especially important for electronic devices that are battery-powered, as it helps to extend their battery life. Another feature of this power supply is its low ripple and noise. The power supply has a ripple voltage of less than 50mV, which ensures that the connected devices receive a stable and noise-free power supply. This is especially important for audio devices, where any noise in the power supply can cause unwanted noise in the audio output. 🧷 TNY268 – Pinout and Description The TNY268 is packaged in a DIP-8B structure for perforated pinouts and an SMD-8B package for SMD. The package is similar to the well-known IC LM555, with the exception of pin 6 hidden in the TNY268, as we can see in the pinout of Figure 2, below. Fig. 2 -Pinout TNY268 🧮 We leave below the description of each pin of the TNY268 Integrated Circuit to facilitate our understanding. DRAIN (D): Power MOSFET drain connection. Provides internal operating current for start-up and steady-state operation. BYPASS (BP): Connection point for an external 0.1 µF bypass capacitor for the internally generated 5.8 V supply. ENABLE/UNDERVOLTAGE (EN/UV): This pin has two functions: input enable and line undervoltage detection. During normal operation, power MOSFET switching is controlled by this pin. MOSFET switching is terminated when a current greater than 240 μA is drawn from this pin.This pin also detects line undervoltage conditions through an external resistor connected to the DC line voltage. If there is no external resistor connected to this pin, TinySwitch-II detects its absence and disables the line undervoltage function. SOURCE (S): Common control circuit, connected internally to the output MOSFET source. SOURCE (HV RTN): MOSFET source connection output for high voltage feedback. 🔌 The Switched Power Supply Circuit The Mini Switched Power Supply Circuit with TNY268 for 5V – 24V, 3A output is a simple yet powerful design, as shown in Figure 3 below. However, due to the involvement of electricity, it requires careful handling and at least intermediate knowledge of electronics to assemble the circuit. Fig. 3 – Schematic Diagram Mini Switching Power Supply 5V – 25V, 3A with TNY268 The schematic diagram of the Mini Switched Power Supply Circuit is well laid out and easy to understand. It includes a TNY268 controller that regulates the output voltage and current of the power supply. The circuit has a few essential components such as capacitors, resistors, diodes, and an inductor, which work together to provide stable and efficient power. 🔗 Related Content   If you liked this project, you might also be interested in these other articles: Symmetrical SMPS Switched Power Supply with IR2153 and IRF840 – 2x50V 350W + PCB Adjustable Switching Power Supply 5.1 to 40V, 2.5 Amp using L4960 + PCB Switched Power Supply SMPS 13.8V 10A using IR2153 IC and IRF840, with PCB How to Modify an ATX Power Supply to 13.6V, 22 Amperes 5A, 1.22V to 26V, 500kHz Step-Down Converter Using RT8289 IC + PCB 4A Low-Noise High-Frequency Step-Up DC-DC Converter using MAX1709 + PCB How ATX Power Supplies Work: Learn to Diagnose Problems in 10 Simple Steps 🔧 Regulate The Output Voltage The output voltage is adjusted through two parameters in the circuit: The D4 diode, which is a 1W Power Zener diode. The secondary winding of the transformer. 📌 The Zener Diode The zener diode D4, is the diode that will adjust the output voltage, we must configure it as follows, when

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Mini Switching Power Supply 5V - 25V, 3A with TNY268 and PCB - Elcircuits

Mini Switching Power Supply 5V – 25V, 3A with TNY268 and PCB

🌐 You can read this article in: Português|Español

Compact 3A Mini Switching Power Supply: Build Your Own 5V-25V Solution with TNY268 and PCB

Hello, electronics enthusiasts!

In this article, we will be discussing a mini switched power supply that provides 5V to 25Vdc output. This power supply is perfect for various electronic devices that require a stable and reliable power supply.

This is a power supply based on the TNY268 Integrated Circuit, which is part of a series of TinySwitch-II circuits: TNY263, TNY264, TNY265, TNY266, TNY267 and TNY268.

For a Flyback-type switched power supply like the one proposed, this IC is ideal, it integrates in its encapsulation the components necessary for it to work:

  • PWM Control, Power Mosfets
  • Overcurrent Protection
  • Over-Temperature Protection
  • Self-Feeding System

It does not need auxiliary windings, which makes it a complete IC, with DIP8 encapsulation, with a PWM working frequency of 132kHz and a voltage of up to 700V.

We will dive into the technical specifications, design, and features of this power supply and how it compares to other similar products in the market.

📖 Technical Specifications

The mini switched power supply has an input voltage range of 80V to 260V AC, which makes it suitable for use in different parts of the world.

It provides an output voltage that can be regulated between 5V to 25V, with a current of up to 3A, depending on the configuration that we choose.

The power supply also has short-circuit protection and overvoltage protection, ensuring the safety of the connected devices.

ℹ️ Design

The mini switched power supply has a compact design, with dimensions of 55mm x 26mm x 21mm. The power supply is enclosed in a plastic case that protects the circuitry from dust and other environmental factors.

The power supply has a standard WJ2EDGVC-5.08-2P connector, making it easy to connect different electronic devices.

⚠️ Caution!⚠️

“This circuit works directly connected to the electrical network, this is extremely dangerous, any carelessness, or wrong connections, design error, or any other occasion, can lead to irreversible damage. We are not responsible for any type of occurrence. If you don’t have enough experience, don’t build this circuit, and if you build it, when testing it, be sure to have the proper protections and be accompanied by someone else.”

🛠️ Features

One of the standout features of this mini switched power supply is its efficiency. It has a high efficiency rating of up to 85%, which means that it wastes less energy as heat compared to other similar products.

This feature is especially important for electronic devices that are battery-powered, as it helps to extend their battery life.

Another feature of this power supply is its low ripple and noise. The power supply has a ripple voltage of less than 50mV, which ensures that the connected devices receive a stable and noise-free power supply.

This is especially important for audio devices, where any noise in the power supply can cause unwanted noise in the audio output.

🧷 TNY268 – Pinout and Description

The TNY268 is packaged in a DIP-8B structure for perforated pinouts and an SMD-8B package for SMD. The package is similar to the well-known IC LM555, with the exception of pin 6 hidden in the TNY268, as we can see in the pinout of Figure 2, below.
Pinout - Pinout TNY268 - Elcircuits

Fig. 2 -Pinout TNY268

🧮 We leave below the description of each pin of the TNY268 Integrated Circuit to facilitate our understanding.

  • DRAIN (D): Power MOSFET drain connection. Provides internal operating current for start-up and steady-state operation.
  • BYPASS (BP): Connection point for an external 0.1 µF bypass capacitor for the internally generated 5.8 V supply.
  • ENABLE/UNDERVOLTAGE (EN/UV): This pin has two functions: input enable and line undervoltage detection. During normal operation, power MOSFET switching is controlled by this pin. MOSFET switching is terminated when a current greater than 240 μA is drawn from this pin.This pin also detects line undervoltage conditions through an external resistor connected to the DC line voltage. If there is no external resistor connected to this pin, TinySwitch-II detects its absence and disables the line undervoltage function.
  • SOURCE (S): Common control circuit, connected internally to the output MOSFET source.
  • SOURCE (HV RTN): MOSFET source connection output for high voltage feedback.

🔌 The Switched Power Supply Circuit

The Mini Switched Power Supply Circuit with TNY268 for 5V – 24V, 3A output is a simple yet powerful design, as shown in Figure 3 below. However, due to the involvement of electricity, it requires careful handling and at least intermediate knowledge of electronics to assemble the circuit.
Schematic Diagram Mini Switching Power Supply 5V - 25V, 3A with TNY268 - Elcircuits

Fig. 3 – Schematic Diagram Mini Switching Power Supply 5V – 25V, 3A with TNY268

The schematic diagram of the Mini Switched Power Supply Circuit is well laid out and easy to understand. It includes a TNY268 controller that regulates the output voltage and current of the power supply. The circuit has a few essential components such as capacitors, resistors, diodes, and an inductor, which work together to provide stable and efficient power.

🔗 Related Content

 

🔧 Regulate The Output Voltage

The output voltage is adjusted through two parameters in the circuit:

  • The D4 diode, which is a 1W Power Zener diode.
  • The secondary winding of the transformer.

📌 The Zener Diode

The zener diode D4, is the diode that will adjust the output voltage, we must configure it as follows, when the desired voltage is Xv, the zener diode must have a voltage Xv – 1. The diode should be 1V lower than the nominal voltage of the power supply, this lower voltage is due to the photocoupler being connected in series with the zener diode, and since it is an “LED” diode, we have the voltage drop on it.

💡 For example:

To obtain a voltage of 5V at the power supply output:
  • The zener diode D4 = 4V. We use a commercial 4.3V, 1N4731 zener diode.
To obtain a voltage of 9V at the power supply output:
  • The zener diode D4 = 8V. We use a commercial 8.2V, 1N4738 zener diode.
To obtain a voltage of 12V at the power supply output:
  • The zener diode D4 = 11V. We use a commercial 11V, 1N4741 zener diode.
To obtain a voltage of 25V at the power supply output:
  • The zener diode D4 = 24V. We use a commercial 24V, 1N4749 zener diode.

🌀 The Transformer

The transformer used in this circuit was a high frequency transformer, often found in PC power supplies, as illustrated in Figure 4 below, a model EE-25 Ferrite transformer.
4 EE-25 Ferrite Transformer - Elcircuits

Fig. 4 EE-25 Ferrite Transformer

✔️ Primary coil winding

The primary will be wound to support a voltage between 85V and 260V, and this will be done by winding 140 turns of 33AWG enamelled wire, or 0.18 mm diameter wire.

Right after winding the primary, place appropriate insulation tape, with electrical and thermal insulation, to insulate the primary from the secondary.

✔️ Secondary coil winding

The secondary will be wound according to the desired output voltage, and this will be done in such a way that, for each desired 1V, 1.4 turns of 17AWG enameled wire or 1.15 mm wire are wound.

👉 The calculation for an output voltage of 5V can be achieved using the formula below:

Formula: N = V * F
  • N = Number of Turns
  • V = Desired Voltage
  • C = Constant = 1.4
  • V = 5V
  • C = 1.4
  • N = ?
  • N = 5 * 1.4
  • N = 7 laps
For 5V on the output, we have 7 turns to wind in the secondary.

👉 The calculation for an output voltage of 9V:

  • V = 9V
  • F = 1.4
  • N = ?
  • N = 9 * 1.4
  • N = 12.6 = ~13 Rounds
For 9V on the output, we have 13 turns to wind in the secondary.

👉 The calculation for an output voltage of 12V:

  • V = 12V
  • F = 1.4
  • N = ?
  • N = 12 * 1.4
  • N = 16.8 = ~17 Rounds
For 12V output, we have 17 turns to wind in the secondary.

👉 The calculation for an output voltage of 24V:

  • V = 25V
  • F = 1.4
  • N = ?
  • N = 25 * 1.4
  • N = 35 Turns

For 24V output, we have 37 turns to wind in the secondary.

The good thing is that with the formula, we can calculate any voltage we want to get at the output of our switching power supply.

🧾 Bill of Materials

Semiconductor

  • U1 ……… Integrated Circuit TNY268P
  • OPT……. TLP181 Opto-Coupler
  • D1, D2 … Diode 1N4007
  • D3 ……… Fast Diode FR307
  • D4 ……… Zener Diode *See Text

Resistor

  • R1 …. Resistor 10Ω / 1W (brown, black, black, gold)
  • R2 …. Resistor 200KΩ / 1/4W (red, black, yellow, gold)
  • R3 …. Resistor 470Ω / 1/4W (yellow, violet, brown, gold)

Capacitors

  • C1 ……. Electrolytic Capacitor 47uF/400V
  • C2 ……. Polyester Capacitor 2.2nF
  • C3 ……. Polyester Capacitor 100nF
  • C4 ……. Electrolytic Capacitor 470uF/35V

Several

  • T1 ……… EE-25 Ferrite Transformer
  • P1, P2 … Connector WJ2EDGVC-5.08-2P
  • Others… PCI, Wires, Solders, Etc.

🖨️ Printed Circuit Board (PCB) – Download

In Figure 5 below, we are making the PCI available in GERBER, PDF and JPEG files, for those who want to create a more optimized assembly, either at home, or if you prefer, at a company that prints the board.
PCB-Mini Switching Power Supply 5V - 25V, 3A with TNY268 - Elcircuits

Fig. 5 – PCB-Mini Switching Power Supply 5V – 25V, 3A with TNY268

📥 Files to Download, Direct Link:

Click on the link beside: GERBER, PDF and PNG files

🧾 Conclusion

In conclusion, the mini switched power supply that provides a programable 5V to 25Vdc output is an excellent choice for various electronic devices. Its compact design, high efficiency, and low ripple and noise make it stand out compared to other similar products in the market.

Its safety features, such as short-circuit protection and overvoltage protection, ensure that connected devices are protected from damage. If you are looking for a reliable and efficient power supply for your electronic devices, then this mini switched power supply is a great choice.

✨ Our Gratitude and Next Steps

We sincerely hope this guide has been useful and enriching for your projects! Thank you for dedicating your time to this content.

Your Feedback is Invaluable:

Have any questions, suggestions, or corrections? Feel free to share them in the comments below! Your contribution helps us refine this content for the entire ElCircuits community.

If you found this guide helpful, spread the knowledge!

🔗 Share This Guide

Best regards,

The ElCircuits Team ⚡

O post Mini Switching Power Supply 5V–25V 3A Using TNY268 – With PCB apareceu primeiro em Electronic Circuits.

]]> https://www.elcircuits.com/mini-switching-power-supply-5v-25v-3a-tny268/feed/ 0 13.8V 10A SMPS Power Supply Using IR2153 and IRF840 – With PCB https://www.elcircuits.com/smps-power-supply-13v8-10a-ir2153-irf840/ https://www.elcircuits.com/smps-power-supply-13v8-10a-ir2153-irf840/#comments Mon, 30 Jan 2023 16:02:00 +0000 https://elcircuits.com/switched-power-supply-smps-13-8v-10a-using-ir2153-ic-and-irf840-with-pcb/ Switched-Mode Power Supply SMPS 13.8V 10A with IR2153 and IRF840 + PCB 🌐 You can read this article in: Português | Español Hello, electronics enthusiasts! Today we’re going to dive into the fascinating world of SMPS (Switched-Mode Power Supply) with a practical and powerful project: a 13.8V power supply capable of delivering up to 10A of continuous current! This project uses the efficient PWM controller IR2153 and the robust MOSFET transistors IRF840, components that together form an unbeatable combination in terms of cost-effectiveness and performance. Whether you’re a student, a professional in the field, a designer, or a hobbyist looking for a reliable power supply for your applications, this article is for you! We’ll unravel each step of this circuit together, from theory to practice, with clear and detailed explanations. 🔍 What is a Switched-Mode Power Supply (SMPS)? Before diving into the project, let’s understand what makes switched-mode power supplies so special. Unlike traditional linear power supplies, which dissipate excess energy as heat, SMPS operate with high-frequency switching, resulting in higher energy efficiency and reduced size. Think of an SMPS as an intelligent system that rapidly “turns on and off” the power, adjusting it to provide exactly what your circuit needs. This switching process occurs at very high frequencies (typically above 20kHz), allowing the use of smaller and lighter components. 🔧 Detailed Circuit Analysis Our 13.8V 10A SMPS power supply project can be divided into 8 fundamental stages, each playing a crucial role in the overall functioning of the circuit. Let’s explore each of them: 📊 Structure of the Switched-Mode Power Supply (SMPS) Protection Circuit Transient Filter Primary Rectification Primary Filter Switching Stage High-Frequency Transformer Fast Rectification Output Filter 1️⃣ Protection Circuit Safety comes first! Our protection circuit consists of a 5A/250V Fuse, which acts as a bodyguard, interrupting the circuit in case of a dangerous overcurrent. In parallel, we have an NTC (Negative Temperature Coefficient), a special thermistor that limits the initial surge current. Think of the NTC as an “intelligent traffic light” for electricity: when the circuit is turned on, it offers high resistance, limiting the initial current. As it heats up, its resistance decreases, allowing normal current flow to occur. This topology is found in most modern SMPS, such as those in laptops and computers. 2️⃣ Transient Filter This stage acts as a “traffic guard” for electricity, preventing high-frequency noise from traveling between our circuit and the power grid. It consists of an initial capacitive filter (C1, C2) that inhibits high frequencies from returning to the grid, and an EMI (Electromagnetic Interference) filter choke, which attenuates the noise generated by switching. 3️⃣ Primary Rectification Here, the alternating current from the power grid (110V or 220V) is converted into pulsating direct current through the rectifier bridge D1. It’s as if we’re transforming the bidirectional flow of electricity into a unidirectional flow, preparing it for the next stages. 4️⃣ Primary Filter The capacitors C3 and C4 act as energy reservoirs, smoothing the ripple of the pulsating direct current and providing a more stable voltage for the switching stage. Think of them as small “energy lakes” that ensure a constant flow. 5️⃣ Switching Stage This is the “magic” of the switched-mode power supply! The heart of this stage is the IR2153 IC, a PWM (Pulse Width Modulation) controller that generates high-frequency signals to control the MOSFET transistors Q1 and Q2 (IRF840). These transistors function as ultra-fast switches, turning on and off at high frequency to “slice” the direct voltage into high-frequency pulses. The IR2153 is particularly interesting because it already incorporates a driver for MOSFETs in its 8-pin package, significantly simplifying the design and reducing the component count. 6️⃣ High-Frequency Transformer Unlike conventional transformers that operate at 60Hz, our Chopper Transformer operates at high frequency, allowing a drastically reduced size with the same power capacity. It is responsible for two crucial functions: galvanically isolating the output circuit from the power grid (essential for safety!) and transforming the high voltage of the primary to the low voltage needed in the secondary. 7️⃣ Fast Rectification In the secondary of the transformer, we need to convert the high-frequency pulses back into direct current. For this, we use the fast diode D3 (MBR3045PT), which is capable of operating efficiently at the high frequencies generated by our circuit. Common diodes would not be suitable here due to their slow recovery time. 8️⃣ Output Filter Finally, the inductor L2 and the capacitor C9 form an LC filter that smooths the residual ripple, providing a clean and stable output voltage of 13.8V. It’s the last barrier between the rectified pulses and the perfectly usable energy that will power your projects. ⚠️ WARNING! ⚠️ This circuit operates directly connected to the power grid, which represents a risk of serious or fatal electric shock. Any carelessness, incorrect connection, or design error can lead to irreversible damage to equipment or even personal accidents. We are not responsible for any type of occurrence. If you do not have sufficient experience with circuits connected to the power grid, do not assemble this circuit. If you decide to assemble it, use all appropriate protections and, if possible, perform the tests accompanied by another person. ⚡ The IR2153 PWM Controller in Detail The IR2153 is the brain of our switched-mode power supply. This integrated circuit from International Rectifier (now part of Infineon) is specifically designed for half-bridge applications in switched-mode power supplies, combining an oscillator with MOSFET drivers in a single package. The IC is powered through the power resistor R3 (27K 5W) together with the capacitor C5. Internally, the IR2153 already has a 15.6V Zener diode to regulate its power supply, but the available current is limited. Therefore, it’s crucial not to use a resistor R3 with a value lower than specified, as this could overload and damage the IC. An interesting improvement would be to add an external 15V Zener diode in parallel with the IC’s power supply, providing additional protection and greater stability. It’s worth highlighting an important difference between the IR2153 and the IR2153D:

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]]>
Switched-Mode Power Supply SMPS 13.8V 10A with IR2153 and IRF840 + PCB
Switched-Mode Power Supply SMPS 13.8V 10A with IR2153 and IRF840 + PCB

🌐 You can read this article in: Português | Español

Hello, electronics enthusiasts!

Today we’re going to dive into the fascinating world of SMPS (Switched-Mode Power Supply) with a practical and powerful project: a 13.8V power supply capable of delivering up to 10A of continuous current! This project uses the efficient PWM controller IR2153 and the robust MOSFET transistors IRF840, components that together form an unbeatable combination in terms of cost-effectiveness and performance.

Whether you’re a student, a professional in the field, a designer, or a hobbyist looking for a reliable power supply for your applications, this article is for you! We’ll unravel each step of this circuit together, from theory to practice, with clear and detailed explanations.

🔍 What is a Switched-Mode Power Supply (SMPS)?

Before diving into the project, let’s understand what makes switched-mode power supplies so special. Unlike traditional linear power supplies, which dissipate excess energy as heat, SMPS operate with high-frequency switching, resulting in higher energy efficiency and reduced size.

Think of an SMPS as an intelligent system that rapidly “turns on and off” the power, adjusting it to provide exactly what your circuit needs. This switching process occurs at very high frequencies (typically above 20kHz), allowing the use of smaller and lighter components.

🔧 Detailed Circuit Analysis

Our 13.8V 10A SMPS power supply project can be divided into 8 fundamental stages, each playing a crucial role in the overall functioning of the circuit. Let’s explore each of them:

📊 Structure of the Switched-Mode Power Supply (SMPS)

  1. Protection Circuit
  2. Transient Filter
  3. Primary Rectification
  4. Primary Filter
  5. Switching Stage
  6. High-Frequency Transformer
  7. Fast Rectification
  8. Output Filter

1️⃣ Protection Circuit

Safety comes first! Our protection circuit consists of a 5A/250V Fuse, which acts as a bodyguard, interrupting the circuit in case of a dangerous overcurrent. In parallel, we have an NTC (Negative Temperature Coefficient), a special thermistor that limits the initial surge current.

Think of the NTC as an “intelligent traffic light” for electricity: when the circuit is turned on, it offers high resistance, limiting the initial current. As it heats up, its resistance decreases, allowing normal current flow to occur. This topology is found in most modern SMPS, such as those in laptops and computers.

2️⃣ Transient Filter

This stage acts as a “traffic guard” for electricity, preventing high-frequency noise from traveling between our circuit and the power grid. It consists of an initial capacitive filter (C1, C2) that inhibits high frequencies from returning to the grid, and an EMI (Electromagnetic Interference) filter choke, which attenuates the noise generated by switching.

3️⃣ Primary Rectification

Here, the alternating current from the power grid (110V or 220V) is converted into pulsating direct current through the rectifier bridge D1. It’s as if we’re transforming the bidirectional flow of electricity into a unidirectional flow, preparing it for the next stages.

4️⃣ Primary Filter

The capacitors C3 and C4 act as energy reservoirs, smoothing the ripple of the pulsating direct current and providing a more stable voltage for the switching stage. Think of them as small “energy lakes” that ensure a constant flow.

5️⃣ Switching Stage

This is the “magic” of the switched-mode power supply! The heart of this stage is the IR2153 IC, a PWM (Pulse Width Modulation) controller that generates high-frequency signals to control the MOSFET transistors Q1 and Q2 (IRF840). These transistors function as ultra-fast switches, turning on and off at high frequency to “slice” the direct voltage into high-frequency pulses.

The IR2153 is particularly interesting because it already incorporates a driver for MOSFETs in its 8-pin package, significantly simplifying the design and reducing the component count.

6️⃣ High-Frequency Transformer

Unlike conventional transformers that operate at 60Hz, our Chopper Transformer operates at high frequency, allowing a drastically reduced size with the same power capacity. It is responsible for two crucial functions: galvanically isolating the output circuit from the power grid (essential for safety!) and transforming the high voltage of the primary to the low voltage needed in the secondary.

7️⃣ Fast Rectification

In the secondary of the transformer, we need to convert the high-frequency pulses back into direct current. For this, we use the fast diode D3 (MBR3045PT), which is capable of operating efficiently at the high frequencies generated by our circuit. Common diodes would not be suitable here due to their slow recovery time.

8️⃣ Output Filter

Finally, the inductor L2 and the capacitor C9 form an LC filter that smooths the residual ripple, providing a clean and stable output voltage of 13.8V. It’s the last barrier between the rectified pulses and the perfectly usable energy that will power your projects.

⚠️ WARNING! ⚠️

This circuit operates directly connected to the power grid, which represents a risk of serious or fatal electric shock. Any carelessness, incorrect connection, or design error can lead to irreversible damage to equipment or even personal accidents.

We are not responsible for any type of occurrence. If you do not have sufficient experience with circuits connected to the power grid, do not assemble this circuit. If you decide to assemble it, use all appropriate protections and, if possible, perform the tests accompanied by another person.

⚡ The IR2153 PWM Controller in Detail

The IR2153 is the brain of our switched-mode power supply. This integrated circuit from International Rectifier (now part of Infineon) is specifically designed for half-bridge applications in switched-mode power supplies, combining an oscillator with MOSFET drivers in a single package.

The IC is powered through the power resistor R3 (27K 5W) together with the capacitor C5. Internally, the IR2153 already has a 15.6V Zener diode to regulate its power supply, but the available current is limited. Therefore, it’s crucial not to use a resistor R3 with a value lower than specified, as this could overload and damage the IC.

An interesting improvement would be to add an external 15V Zener diode in parallel with the IC’s power supply, providing additional protection and greater stability.

It’s worth highlighting an important difference between the IR2153 and the IR2153D: the “D” model already incorporates internally the diode D2 (FR107 or BA159) necessary for the proper functioning of the circuit. If you’re using the IR2153D, you can omit this component. If it’s the IR2153 (without the “D”), keep the diode D2 as shown in the schematic.

🔌 Complete Schematic Diagram

Now that we understand each part of the circuit, let’s examine the complete schematic diagram in Figure 2. This is the moment when all the pieces of the puzzle fit together, forming a cohesive and functional system.

Schematic Diagram SMPS Power Supply 13.8V 10A
Figure 2 – Schematic Diagram SMPS Power Supply 13.8V 10A

🔧 The Transformer: Heart of the Switched-Mode Power Supply

The transformer TR1 is a critical component in our power supply. For this project, we used a transformer model IE-35A recovered from a scrap ATX power supply. The good news is that practically any ATX power supply transformer can be used, as long as we follow the correct pinout.

One of the great advantages of this project is that there is no need to rewind the transformer! You just need to correctly identify the terminals and connect them as shown in Figure 3 below. This approach saves time and eliminates one of the most complex steps in building switched-mode power supplies.

ATX power supply transformer connection diagram
Fig. 3 – ATX power supply transformer connection diagram

In addition to the EI-35A model, other transformers from AT or ATX power supplies can be used, such as the models EI-33, ER35, TM3341101QC, ERL35, EI28, among others. Figure 4 shows an example of the EI-35A transformer we used:

ATX power supply transformer model EI-35A
Fig. 4 – ATX power supply transformer model EI-35A

As for the inductors L1 and L2, both can be salvaged from the original ATX power supply. The inductor L1 is the input EMI filter, while L2 is the output filter. If you prefer to build your own filter, you can wind an inductor on a ferrite toroidal core using 0.6 mm enameled copper wire with approximately 25 turns.

📝 Complete List of Components

To facilitate your assembly, we’ve compiled a detailed list of all the necessary components for this project:

Component Specification Notes
IC1 Integrated Circuit IR2153D or IR2153 See text for differences
Q1, Q2 MOSFET Transistors IRF840 Can be replaced by equivalents
R1, R2 150k Resistor (brown, green, yellow, gold)
R3 27K 5W Resistor (red, violet, orange, gold)
R4 8K2 Resistor (gray, red, red, gold)
R5, R6 10Ω Resistor (brown, black, black, gold)
D1 KBU606 Diode Bridge Or equivalent
D2 Fast Diode FR107 or BA159 Not needed with IR2153D
D3 Fast Diode MBR3045PT Or equivalent
C1, C2 470nF – 400Vac Polyester Capacitor X2 Class
C3, C4 330uF – 200V Electrolytic Capacitor Low ESR recommended
C5, C7 100uF – 25V Electrolytic Capacitor Low ESR recommended
C6 680pF Polyester Capacitor Polystyrene recommended
C8 2.2uF – 400V Polyester Capacitor Polypropylene recommended
C9 2200uF – 25V Electrolytic Capacitor Low ESR recommended
RV1 47kΩ Trimpot For voltage adjustment
NTC1 5Ω Thermistor Surge current limiter
L1, L2 Inductors See text
TR1 Transformer See text
F1 5A Solderable Fuse Overcurrent protection

🖨️ Printed Circuit Board (PCB)

To facilitate your assembly, we’ve made the PCB (Printed Circuit Board) files available in different formats, covering all your needs, whether for a homemade assembly or for sending to a professional fabrication.

The files are available in GERBER format (for professional fabrication), PDF (for viewing and printing) and PNG (for visual reference). And best of all: they are available for free download directly from the MEGA server, through a direct link, without any complications or redirections!

PCB Switched-Mode Power Supply SMPS 13.8V 10A with IR2153 and IRF840
Fig. 5 – PCB Switched-Mode Power Supply SMPS 13.8V 10A with IR2153 and IRF840

📥 Download Files

To download the necessary files for assembling the electronic circuit, just click on the direct link provided below:

Link to Download: Download Files (PCB Layout, PDF, GERBER, JPG)

🤔 Frequently Asked Questions (FAQ)

To ensure your project is a success, we’ve compiled some of the most common questions on this topic. Check it out!

Can I use other MOSFET models besides the IRF840? 🔽

Yes, you can use other MOSFETs equivalent to the IRF840, as long as they meet the minimum specifications for voltage (minimum 500V), current (minimum 8A), and have low on-resistance (Rds(on)). Some models that can be used as substitutes include IRF740, IRF830, STP8NM50, among others. Always check the datasheet to ensure compatibility.

How to adjust the output voltage to values different from 13.8V? 🔽

The output voltage can be adjusted through the trimpot RV1. Turn it carefully with a small screwdriver while monitoring the output voltage with a multimeter. The circuit allows adjustment approximately between 11V and 15V. Remember that changing the output voltage will also affect the maximum available current, keeping the total maximum power at approximately 140W.

Is it possible to modify this circuit to provide more than 10A? 🔽

Yes, it’s possible to modify the circuit to provide more current, but this will require several important changes: MOSFETs with higher current capacity, transformer with thicker wire on the secondary, output diodes with higher current capacity, and output filter capacitors with higher capacitance. Additionally, the MOSFET heat sink will need to be resized. These modifications should be made with care and advanced technical knowledge.

Does this circuit have short-circuit protection? 🔽

The basic circuit presented does not have electronic short-circuit protection, only the fuse F1 as protection against severe overcurrent. To add short-circuit protection, it would be necessary to implement a current monitoring circuit that shuts down the PWM controller when it detects an overcurrent. This is a recommended modification for more critical applications.

What is the operating frequency of this circuit? 🔽

🎓 Conclusion and Next Steps

Building your own SMPS power supply is a challenging but extremely rewarding project. Besides saving money, you gain deep knowledge about how modern power supplies work, essential in practically all electronic equipment we use daily.

We hope this detailed guide has been useful for your journey in electronics. Always remember to prioritize safety when working with circuits connected to the power grid and don’t hesitate to seek help if you have doubts.

✨ Our Gratitude and Next Steps

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The ElCircuits Team ⚡

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