Tuesday, February 8, 2022

440W Class AB Power Amplifier using Mosfet IRFP9240 and IRFP240 Transistors with PCB


Fig. 1 - 440W Class AB Power Amplifier using Mosfet IRFP9240 and IRFP240 Transistors with PCB


This is a high performance power amplifier, which despite its simplicity in construction, in the tests performed, it presented parameters with great results, very close to what we call a HI-FI amplifier.

The Circuit Works

The complexity of the circuit is at an advanced level, it is not recommended for those who don't have experience in electronics and in assembling amplifier circuits, you must have minimal knowledge at an advanced level to assemble this type of power amplifier.

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The circuit diagram of the power amplifier is shown in Figure 2 below. It uses 8 output Mosfet power transistors, 4 transistors for the positive cycle and 4 transistors for the negative cycle. 

Fig. 2 - Schematic diagram 440W Class AB Power Amplifier using Mosfet IRFP9240 and IRFP240 Transistors 

The input circuit consists of a TL431 Op-Amp, it is used as a feed-forward preamplifier for the driver circuit units that produce a primary voltage gain at the output stage.

The circuit is divided into 2 identical half-cycles: one side for the positive half-wave of the signal fed through driver transistor Q1 NPN BD139, which feeds the output transistors (Q3, Q5, Q7, Q9 ) P-Channel IRFP9240, the other side for the negative half-wave of the signal fed through driver transistor Q2 PNP BD140, which feeds the output transistors (Q4, Q6, Q8, Q10) N-Channel IRFP240.

The Power Supply 

The power supply is of the symmetrical type, with a supply voltage of +55V | 0V | -55V, with a current of 10 Amperes, with good filtering. 

In Figure 3 below, we have a suggestion for a power supply that we use in our projects. In this article, besides having the schematic diagram with the Printed Circuit Board, you will understand how to easily calculate your own Power Supply, with the desired voltage.

You can in the link below:

Fig. 3 - Symmetrical Power Supply for Power Amplifiers

Components List

  • Semiconductors
    • U1 .......................... TL071 Integrated Circuit
    • Q1 .......................... BD139 NPN Transistor
    • Q2 .......................... BD140 PNP Transistor
    • Q3, Q4, Q5, Q6 ..... IRFP9240 Mosfet Transistor
    • Q7, Q8, Q9, Q10 ... IRFP240 Mosfet Transistor
    • D1, D2 ................... 1N4744 15V Zener diode
      D3, D4 ................... 1N4148 diode

  • Resistor
    • R1, R33 ................. 47KΩ (yellow, violet, orange, gold
    • R2 .......................... 1KΩ  (brown, black, red, gold)
    • R3, R4 .................... 2K7Ω (red, violet, red, gold)
    • R5, R6 .................... 2KΩ (red, black, red, gold)
    • R7 ........................... 6k8Ω Trimpot 
    • R8, R9 .................... 22KΩ (red, red, orange, gold)
    • R10, R11 ................ 33Ω (orange, orange, black, gold)
    • R12, R13 ................ 220Ω (red, red, brown, gold)
    • R14, R5 .................. 820Ω ( grey, red, brown, gold)
    • R16 ......................... 3.3Ω (orange, orange, gold, gold)
    • R17, R18, R21, R22, R25, R26, R29, R30 .... 39Ω (orange, white, black, gold)
    • R19, R20, R23, R24, R27, R28, R31, R32 .... 5W 0.33Ω (orange, orange, silver, gold)
  • Capacitor
    • C1, C5 .................... 100pF Ceramic Capacitor
    • C2, C6, C7 .............. 1uF Ceramic Capacitor
    • C3, C4, C9, C10 ..... 470uF / 65V Electrolytic Capacitor 
    • C8 ........................... 100nF Ceramic Capacitor


  • Miscellaneous 
    • P1 .......... 2-pin PCB soldering terminal blocks
    • P2 .......... 3-pin PCB soldering terminal blocks
    • Others .... Printed Circuit Board, heat sink, wires, etc.


We are offering the PCB - Printed Circuit Board, in GERBER, PDF and PNG files, for you who want to do the most optimized assembly, either at home, or if you prefer in a company that develops the board, you can is downloading and make the files in the Download option below.
Fig. 3 - 440W Class AB Power Amplifier using Mosfet IRFP9240 and IRFP240 Transistors

Files to Download, Direct Link:

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

If you have any questions, suggestions or corrections, please leave them in the comments and we will answer them soon.

Subscribe to our blog!!! Click Here - elcircuits.com!!!

My Best Regards!!!


Monday, February 7, 2022

USB 5V 4A Car Charger using 78S05 with PCB

Fig. 1 - USB 5V 4A Car Charger using 78S05

This is a simple USB 5V 4A Car Charger circuit to charge a cell phone, tablet, or any other gadget that requires a voltage of 5V with a current of 2 Amperes via USB.

The circuit is a DC converter that takes power from a cigarette lighter socket in your vehicle, and converts the 12V battery voltage to a stabilized 5V voltage.

There are several models of USB chargers on the market, the problem is the high price, and the supply current is quite low, around 400mA to 600mA, smartphones currently have chargers with 1000mA, 1500mA, 2000mA... 

The circuit is based on the LM78S05 IC, it is extremely easy to build, using very few components. 

L78S00 Description

The L78S00 series of three-terminal positive regulators  is available in TO-220 and TO-3 package sand  with several  fixed output  voltages, making it useful in a wide range of applications. 

These regulators can provide local on card regulation, eliminating the distribution problems associated with single point regulation. Each type employs internal current limiting, thermal  shut-down and safe area protection, making it essentially indestructible. 

If adequate heat sinking is provided, they can deliver over 2A output current. Although designed primarily as fixed voltage regulators, these devices can be used with external components to obtain adjustable voltage sand currents.

Feature

  • Output Current to 2A.
  • Output  Voltage of: 5 ; 7.5 ; 9 ; 10 ; 12 ; 15 ;18 ; 24V.
  • Thermal Overload Protection.
  • Short Circuit Protection.
  • Output Transistor SOA Protection

Circuit Operation

In Figure 2, below, we can see the schematic diagram of USB 5V 4A Car Charger using 78S05, the Circuit's operation is pretty basic, what happens is that when you plug your USB converter into the cigarette socket of your car, it converts this 12V battery voltage to a regulated 5V voltage.

Fig. 2 - Schematic circuit USB 5V 4A Car Charger using 78S05

The total output current of the circuit is 4 Amps, 2A for each USB port, this is enough current to charge any USB device today.

The circuit has overload protection, which means that if there is a short circuit on the output, or if a device with higher current is connected to the USB converter, it will shut down, until that current is reduced to a maximum of 2A.

Components List

  • Semiconductors
    • U1, U2 ...... 78S05 Integrated Circuit Voltage regulator
    • LED1 ....  Light Emitter Diodo, general purpose

  • Resistor
    • R1 ..... 4.7KΩ (yellow, violet, orange, gold
    • RP1 ......... 10KΩ Trimpot
  • Capacitor
    • C1 .......... 47nF Ceramic Capacitor
    • C2 .......... 100nF Ceramic Capacitor
    • C3 .......... 4.700uF / 35V Electrolytic Capacitor 

  • Miscellaneous 
    • F1 .......... 20A - 250V soldering Fuse
    • P1 .......... 2-pin PCB soldering terminal blocks
    • P2 .......... 3-pin PCB soldering terminal blocks
    • Others .... Printed Circuit Board, heat sink, wires, etc.

Printed Circuit Board

In Figure 3, we provide the PCB - Printed Circuit Board, in GERBER, PDF and PNG files. These files are available for free download, on the MEGA server, in a direct link, without any bypass. 

All to make it easier for you to do a more optimized assembly, either at home, or with a company that prints the board. You can download the files in the Download option below.

Fig. 3 - PCB - USB 5V 4A Car Charger using 78S05

Files to Download, Direct Link:

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

If you have any questions, suggestions or corrections, please leave them in the comments and we will answer them soon.

Subscribe to our blog!!! Click Here - elcircuits.com!!!

My Best Regards!!!


Sunday, February 6, 2022

12V to 220V 60Hz 500W Inverter using IR2153D with PCB

Fig. 1 - 12V to 220V 60Hz 500W Inverter using IR2153D with PCB

You know that moment when you are at home tired from work, ready for bed, and suddenly the power goes out? Yes my friends, it is a moment that we don't want to happen, but we know it happens.

The best thing in these moments is to have something that can supply our power outage problem... With this we present a simple circuit, easy to build and very cheap.

I present to you a simple circuit to build, whose purpose is precisely to provide AC power to feed a fan, the lights, and some electronic equipment, with a 12V battery.

Integrated Circuit IR2153D

The IR2153D is an improved version of the popular IR2155 and IR2151 gate driver ICs, and incorporates a high voltage half-bridge gate driver with a front end oscillator similar to the industry standard CMOS 555 timer.  

The IR2153D provides more functionality and is easier to use than previous ICs.  A shutdown feature has been designed into the CT pin, so that both gate driver outputs can be disabled using a low voltage control signal. 

In addition, the gate driver output pulse widths are the same once the rising under voltage lock out threshold on VCC has been reached, resulting in a more stable profile of frequency vs time at startup. 

Noise immunity has been improved significantly, both by lowering the peak di/dt of the gate drivers, and by increasing the under-voltage lockout hysteresis to 1V

Finally, special attention has been payed to maximizing the latch immunity of the device, and providing comprehensive ESD protection on all pins.

Features

  • Integrated 600V half-bridge gate driver
  • 15.6V zener clamp on Vcc
  • True micropower start up
  • Tighter initial deadtime control
  • Low temperature coefficient deadtime
  • Shutdown feature (1/6th Vcc) on CT pin
  • Increased under-voltage lockout Hysteresis (1V)
  • Lower power level-shifting circuit
  • Constant LO, HO pulse widths at startup
  • Lower di/dt gate driver for better noise immunity
  • Low side  output in phase with RT
  • Internal 50nsec (typ.) bootstrap diode (IR2153D)
  • Excellent latch immunity on all inputs and outputs
  • ESD protection on all leads
  • Also available LEAD-FREE

Circuit Works

In Figure 2, below, we can see the schematic diagram of 12V to 220V 600Hz 500W inverter, the circuit works in a simple and direct way, when feeding the circuit the IR2153D IC starts operating, and triggers a square wave in the GATEs of the output MOSFETs transistors.
Fig. 2 - Schematic Circuit 12V to 220V 60Hz 500W Inverter using IR2153D with PCB

This triggering is done by cycle, when triggering the HO output, pin 7 is at HIGH, and the MOSFETs are activated, in the next cycle the work, the HO output is turned off, and the LO output is activated, that is, pin 5 is set to HIGH, and this cycle repeats.

This causes an oscillation in the secondary of the transformer, generating a magnetic field that will be passed to the primary of the transformer, which is the output, thus generating an output voltage of 110V or b at a frequency of 50Hz or 60Hz, this frequency is adjusted in the trimpot.

Transformer

The transformer is a network transformer with secondary windings with 10V center tape, and should have a power according to the consumption power, or load that you will use. 

Power Supply - Safety Voltage

The power supply must have enough current to provide the circuit's consumption demand. The supply voltage should be in the 9 - 14V  range. 

If the supply voltage drops too low and falls below 9V, the IR2153D circuit will shut down, preventing damage to the battery or battery bank, or to the inverter circuit.

Efficiency and Consumption

The battery, or batteries bank, must provide a sufficiently high current, according to the consumption of your device, for example, for a 100W consumption of the inverter, you should take into account a battery that supplies this power.

Considering that the average efficiency factor of this equipment is approximately 80%, we will consider that for an average consumption of 100W, we will use a basic account for this:
Power in W of the load * 1.2 (20% efficiency loss) = Power in W of the Inverter

So:
100W of the load x 1.2 = 120W total

So let us now use ohms law to formulate our account:
  • General formula:
    • P = V * I
A consumption of 120W with a battery voltage of 12V, we would be left with:
  • I = P / V
  • I = 120 / 12
  • I = 10A
For a 100W load we would have a consumption of 10A per hour.

Components List

  • Semiconductors
    • U1 .......... IR2153D Integrated Circuit
    • Q1 to Q6 .... IRF3205 N-Channel Power Mosfet

  • Resistor
    • R1 ........... 47KΩ (yellow, violet, orange, gold
    • RP1 ......... 10KΩ Trimpot
  • Capacitor
    • C1 .......... 47nF Ceramic Capacitor
    • C2 .......... 100nF Ceramic Capacitor
    • C3 .......... 4.700uF / 35V Electrolytic Capacitor 

  • Miscellaneous 
    • F1 .......... 20A - 250V soldering Fuse
    • P1 .......... 2-pin PCB soldering terminal blocks
    • P2 .......... 3-pin PCB soldering terminal blocks
    • Others .... Printed Circuit Board, heat sink, wires, etc.

Printed Circuit Board

In Figure 3, we provide the PCB - Printed Circuit Board, in GERBER, PDF and PNG files. These files are available for free download, on the MEGA server, in a direct link, without any bypass. 

All to make it easier for you to do a more optimized assembly, either at home, or with a company that prints the board. You can download the files in the Download option below.

Fig.  3 -PCB - 12V to 220V 60Hz 500W Inverter using IR2153D

Files to Download, Direct Link:

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

If you have any questions, suggestions or corrections, please leave them in the comments and we will answer them soon.

Subscribe to our blog!!! Click Here - elcircuits.com!!!

My Best Regards!!!


Thursday, February 3, 2022

FM Transmitter 70MHz to 150MHz using MAX2606 IC with PCB

Fig. 1 - FM Transmitter 70MHz to 150MHz using MAX2606 IC with PCB

This is a low power micro FM transmitter with a voltage controlled oscillator, VCO, that covers the FM Modulated Frequency bands from 88 to 108Mhz, adjusted by a trimpot. 

The transmitter is based on the MAX2606 integrated circuit, which brings us great advantages, and one of the main ones is that the transmitter has a very small size, and can also be used for "Espionage". 

The MAX2606 Integrated Circuit

The MAX2606 is a compact high-performance intermediate-frequency (IF) Voltage Controlled  Oscillators (VCOs) designed  specifically  for  demanding  portable wireless communication systems. 

They combine monolithic  construction  with  low-noiselow-power  operation  in  a tiny 6-pin SOT23 package, as showed in Figure 2 above.
Fig. 2 - Pinout MAX2606 Integrated Circuit

These low-noise VCOs feature an on-chip varactor and feedback capacitors that eliminate the need for external tuning  elements,  making  the  MAX2605–MAX2609  ideal for  portable  systems.  

Only  an  external  inductor  is required to set the oscillation frequency. In addition, an integrated  differential  output  buffer  is  provided  for  driving a mixer or pre-scaler. 

The buffer output is capable of  supplying  up  to  -8dBm  (differential)  with  a  simple power match. It also provides isolation from load impedance variations. 

The  MAX2606  operate  from  a  single  +2.7V  to +5.5V power supply and offer low current consumption. These IF oscillators  can  cover  the  70MHz  to 150MHz  frequency range.

Features

  • Small Size 
  • Integrated Varactor for Tuning
  • Low Phase Noise
  • Wide Application Frequency Range
  • Differential or Single-Ended Outputs
  • Single +2.7V to +5.5V Supply
  • Ultra-Small SOT23-6 Package
  • On-Chip Temperature-Stable Bias
  • Low-Current Operation

ATTENTION!

For each Country, Region, State... There are Laws on broadcasting, telecommunications, audio and video transmission, etc.

Do not use telecommunications equipment without authorization from the entities responsible for transmitting Radio Frequencies.

Electronic Circuits teaches electronics applied to various segments, with the aim of improving knowledge, we do not support or take responsibility for any type of illegal operation.

For any operation with RF, we recommend looking for the competent regulatory agencies, seeking certification and/or legalization.

Transmitter Operation

This FM Transmitter circuit has its frequency adjustment through a Varicap diode built in the MAX2606 chip, this means that the frequency oscillator of the transmitter is controlled by applying voltage to input pin 3 of the MAX2606 chip.

The Frequency

The nominal frequency of the transmitter using the MAX2606 is 70 to 150 MHz, however, for our project we used a 390uH coil, which sets the frequency of the transmitter oscillator to the range 88 to 108 MHz.

Audio Input

The audio input is balanced through two resistors R1 and R2, so we can work with stereo input.

The RP2 Trimpot controls the gain of the transmitter's audio input, remembering that the audio input signal should not exceed 60mV to avoid distortions.

Frequency Adjustment

The RP1 Trimpot controls the oscillation frequency of the transmitter, varying the commercial FM frequency range from 88 to 108 MHz.

The antenna consists of a piece of wire approximately 75 cm long.

The coil L1 is 390mH, in case you cannot get a commercial coil, you can build one with approximately 8 to 14 turns of 0.5mm diameter copper wire wrapped around a 5mm core

To make a finer adjustment, you can be compressing or expanding the coil, and thus change its inductance.

The Power Supply

The MAX2606 integrated circuit works with a supply voltage ranging from 2.7 to 5.5Vdc with a current of 2.1mA. If you are going to use a power supply it is recommended to have good filtering, since Radio Frequency Transmitters are very sensitive to interference.

But, as most already intend to do with batteries, it is recommended not to use long wires, so as not to pick up external electromagnetic interference.

The Circuit

In Figure 2 below we can see the schematic diagram of FM Transmitter 70MHz to 150MHz using MAX2606 IC.

It is a circuit that has moderate difficulty, and should be assembled by people who have at least an intermediate level of knowledge
Fig. 3 - Schematic Circuit FM Transmitter 70MHz to 150MHz using MAX2606 IC

Components List

  • Semiconductors
    • U1 .......... MAX2606 Integrated Circuit

  • Resistor
    • R1, R2 ..... 22KΩ (red, red, orange, gold)
    • R3 ............ 4.7KΩ (yellow, violet, red, gold
    • R4 ............ 270Ω (red, violet, brown, gold)
    • R5, R6 ..... 1KΩ (brown, black, red, gold)
    • RP1 ......... 100KΩ Trimpot
    • RP2 ......... 10KΩ Trimpot

  • Capacitor
    • C1 .......... 10uF / 16V Electrolytic Capacitor
    • C2 .......... 0.47uF / 16V Electrolytic Capacitor
    • C3 .......... 680pF Ceramic Capacitor
    • C4 .......... 1nF Ceramic Capacitor
    • C5 .......... 100nF Polyester/Ceramic Capacitor
    • C6 .......... 220uF / 16V Electrolytic Capacitor
       
  • Miscellaneous 
    • P1 .......... 3-pin PCB soldering terminal blocks
    • P2 .......... 2-pin PCB soldering terminal blocks
    • Others .... Printed Circuit Board, tin, wires, etc.

Printed Circuit Board

In Figure 3, we provide the PCB - Printed Circuit Board, in GERBER, PDF and PNG files. These files are available for free download, on the MEGA server, in a direct link, without any bypass. 

All to make it easier for you to do a more optimized assembly, either at home, or with a company that prints the board. You can download the files in the Download option below.

Fig. 3 - PCB - FM Transmitter 70MHz to 150MHz using MAX2606 IC

Files to Download, Direct Link:

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

If you have any questions, suggestions or corrections, please leave them in the comments and we will answer them soon.

Subscribe to our blog!!! Click Here - elcircuits.com!!!

My Best Regards!!!


Thursday, January 27, 2022

12 Volts Automatic Lead Acid Battery Charger Using LM350 IC with PCB

Fig, 1 - 12 Volts Automatic Lead Acid Battery Charger Circuit + PCB

This is a 12V Automatic Lead Acid Battery Charger Circuit, of the type used in nobreaks, with loads ranging from 1A to 9 Amps.

The main advantage of this battery charger circuit is its charging mode, since it has a charge control, so that the battery does not receive voltage when it is not needed, giving more autonomy to the battery and protecting it from overvoltage.

What is Lead Acid Battery

The lead acid battery is a type of rechargeable battery first invented in 1859 by French physicist Gaston Planté

It is the first type of rechargeable battery ever created. Compared to modern rechargeable batteries, lead-acid batteries have relatively low energy density. 

Despite this, their ability to supply high surge currents means that the cells have a relatively large power-to-weight ratio. 

These features, along with their low cost, make them attractive for use in motor vehicles to provide the high current required by starter motors.

Lead Acid Battery Charger Method

There are several features related to the charging process of various battery segments and classes. 
The charging method for lead-acid batteries differs from NiCd batteries in the voltage limit, rather than the current limit to be used.

The charging time for lead-acid (sealed) batteries is 8 to 16 hours, depending on the capacity of the battery and the method used. 

With higher charging currents and multi-stage charging methods, the charging time can be reduced to 8 hours or less. 

For a multi-stage charger, three stages of charging application are required: 
  •  Constant current
  •  Peak charge
  •  Float charge

The Circuit

In Figure 2 below, we have the schematic diagram of the lead-acid battery charger circuit. It is a very simple circuit, with few external components, easy to assemble, yet even with its simplicity it works very well.
Fig. 2 - Schematic Circuit 12 Volts Automatic Lead Acid Battery Charger Circuit

Working

The voltage regulation for charging the battery is done by the LM350 IC voltage regulator. 
The charging current control is done using the BC548B NPN transistor, it controls the demand current from the battery, causing the circuit to activate or deactivate the voltage required for charging the battery.

The potentiometer RP1 1K is used for fine tuning the battery charging voltage, which should be adjusted by using a multimeter to measure the output voltage, which should be at most 20% of the nominal battery voltage.

If you cannot find the description of the battery charging voltage on the battery itself, you can adjust the average charging voltage, which ranges from 13.8V to 14.4V.

It is necessary to use a heat sink in the voltage regulator, since the initial current to charge the battery is high. 
As the circuit charges the battery, it lowers the charging current until it reaches zero voltage, when the battery is fully charged.

Components List

  • Semiconductors
    • U1 .......... LM350 Voltage Regulator Circuit
    • Q1 .......... BC548B NPN Transistor
    • D1 .......... 1N5408 Silico Diode

  • Resistor
    • R1 .......... 100Ω Resistor (brown, black, brown, gold)
    • R2 .......... 0.5Ω 5W Resistor (green, black, silver, gold
    • R3 .......... 470Ω Resistor (yellow, violet, brown, gold)
    • R4 .......... 120Ω Resistor (brown, red, brown, gold)
    • RP1 ........ 1KΩ Potentiometer

  • Capacitor
    • C1 .......... 2.2uF / 25V Electrolytic Capacitor
    • C2 .......... 0.33uF / 25V Electrolytic Capacitor
       
  • Other
    • P1, P2 .... 2-pin PCB soldering terminal blocks
    • Others .... Printed Circuit Board, Heat Sink, tin, wires, etc.

Printed Circuit Board

In Figure 3, we provide the PCB - Printed Circuit Board, in GERBER, PDF and PNG files. These files are available for free download, on the MEGA server, in a direct link, without any bypass. 

All to make it easier for you to do a more optimized assembly, either at home, or with a company that prints the board. You can download the files in the Download option below.

Fig. 3 - PCB - 12 Volts Automatic Lead Acid Battery Charger Circuit


Files to Download, Direct Link:

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

If you have any questions, suggestions or corrections, please leave them in the comments and we will answer them soon.

Subscribe to our blog!!! Click Here - elcircuits.com!!!

My Best Regards!!!


Wednesday, January 26, 2022

Lithium (Li-Ion) Battery Charger using LP2951 IC + PCB

Fig. 1 - Lithium (Li-Ion) Battery Charger using LP2951 IC + PCB

Para versão em Português, Clique Aqui!

This is a complete and compact Li-Ion battery charger circuit, composed of Integrated Circuit LP2951

The circuit performs assisted and controlled charging, and this represents a longer life for your battery and a full charge giving more autonomy in the circuits powered by these batteries.

It is a very simple circuit to assemble, because the external components are minimal, due to the IC having integrated in its encapsulation all the necessary components to perform the task.

LP2951 Integrated Circuit

The LP2951 is an adjustable micro power voltage regulator suitable  for  use  in  battery-powered  systems.  

This  regulator has  various  functions  such  as  alarm  which  warns  of  a  low output voltage, often due to falling batteries on the input, the external   shutdown   which   enables   the   regulator   to   be switched on and off, current and temperature limiting.

Additional Features

The LP2951 has three additional features: 

  • 1st - Error output that can be used to signal external circuits of an out-of-regulation condition or as a microprocessor reset trigger. 
  • 2nd - Allows the output voltage to be preset to 5.0 V, 3.3 V or 3.0 V (depending on the version) or programmed from 1.25 V to 29 V. It consists of a fixed resistor divider along with direct access to the Error input on the internal operational amplifier feedback. 
  • 3rd - It has a shutdown input that allows a logic level signal to turn the regulator output off or on.

What it is used for

Due to the low specifications for input to output voltage differential and bias current, this device is ideal for computers, consumers, and battery powered industrial equipment where extended battery life is desirable, battery charger. 

The LP2951 is available in eight-pin dual-line, SOIC-8 and Micro-8 surface mount packages. Devices with an 'A' suffix have an initial output voltage tolerance of ± 0.5%.

Features

  • Low Quiescent Current 
  • Low Dropout Voltage
  • Low Temperature Coefficient
  • Tight Line and Load Regulation
  • Guaranteed 100mA Output Current
  • Internal Short Current & Thermal Limit
  • Error Signals of Output Dropout (8 pin Versions only)
  • External Shut Down ( 8-Pin Versions Only)

The Circuit

In Figure 2 below we can see the schematic diagram of the Li-Ion battery charger, the LP2951 IC is responsible for measuring the state of the battery through the voltage divider, at the charging voltage output of the battery, and thereby control it to not emit an unnecessary charge.
Fig. 2 - Schematic Diagram Lithium (Li-Ion) Battery Charger using LP2951 IC


Capacitor C1 and C2 act as an RF filter to eliminate spurious, capacitor C3 is for stability of the feedback system, the 50K potentiometer RP1 is to adjust the system according to the operating voltage of the cell.

The Li-Ion battery charger circuit can be powered by a DC voltage between 6 to 10V with a current equal to 1.5 times the capacity of the cells to be charged.

Charger Operation

When we connect the power supply to the circuit and insert the battery, the LP2951 IC checks the charging status and, when it detects a charge below the programmed one, it triggers the charging to complete the charge.

After the battery is fully charged, the circuit goes into sleep mode, it keeps checking periodically the status of the battery and if necessary it activates the continuity of charging. 

Components List

  • Semiconductors
    • U1 .......... LP2951 Voltage Regulator Circuit
    • D1 .......... 1N4007 Silico Diode

  • Resistor
    • R1 .......... 2MΩ 1%  Precision Resistor (red, black, yellow, brown)
    • R2 .......... 806KΩ 1%  Resistor (gray, black, blue, orange, brown
    • RP1 ........ 50KΩ Potentiometer

  • Capacitor
    • C1 .......... 0.1uF or 100nF Polyester/Ceramic Capacitor
    • C2 .......... 2.2uF / 16V Electrolytic Capacitor
    • C3 .......... 470pF Polyester/Ceramic Capacitor
       
  • Other
    • B1, B2 ... 2-pin PCB soldering terminal blocks
    • Others .... Printed Circuit Board, tin, wires, etc.

Printed Circuit Board

In Figure 3, we provide the PCB - Printed Circuit Board, in GERBER, PDF and PNG files. These files are available for free download, on the MEGA server, in a direct link, without any bypass. 

All to make it easier for you to do a more optimized assembly, either at home, or with a company that prints the board. You can download the files in the Download option below.

Fig. 3 - PCB - Lithium (Li-Ion) Battery Charger using LP2951 IC

Files to Download, Direct Link:

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

If you have any questions, suggestions or corrections, please leave them in the comments and we will answer them soon.

Subscribe to our blog!!! Click Here - elcircuits.com!!!

My Best Regards!!!