The LM317HV is an adjustable 3-terminal positive voltage regulator capable of supplying 1.5 A or more currents over a 1.25V to 57V output voltage range. It requires only two external resistors to set the output voltage. The LM317HV is packaged in standard transistor packages that are easily mounted and handled.
However, the LM317HV supports high voltage, but the current is still low, only 1.5A, our circuit, we are increasing a drive circuit to increase the current we need to 6 Amps, with three TIP36C transistors, which provides an adjustable output voltage between 1.25v to 57 volts, with a current of 6 Amps, which is enough for a bench power supply.
The schematic electrical diagram, which follows in Figure 2 below, it's very simple, first one, we have the voltage input that comes through connector J1, which enters through resistor R1, that as long as there is no current greater than the one calculated, there is no drop of voltage in R1, more if the current increases, there will be a voltage drop of approximately 0.6V, which will cause the transistors to saturate, causing the current to pass through the power transistors.
The capacitor C1 has the objective of attenuating the interference of the ripples and their stability. Capacitor C2 has the function of eliminating high interference, and capacitor C3 has the function of constancy to decrease the ripple and stability of the power supply.
P1, is a 5K analog potentiometer, if you don’t have 5K you can put 4.7K, which is more commercial, the diodes D1 and D2 are to avoid reverse voltage over the Integrated Circuit U1, and in the transistors, resistors R3, R4 and R5, are impact resistors, which attenuate the difference between the transistors and prevent one from working more than the other.
Fig. 2- Adjustable Power Supply Schematic LM317HV + TIP36
Components list
U1…………….... LM317HV – Integrated circuit, voltage regulator
Others ............… Printed Circuit Board, tin, wire, etc.
We are offering to Download the link with the printed circuit board printing files, they are; Gerber, PDF layout, PNG, all the files with a direct link to Mega.
Nowadays it is very important and necessary to have abench power supplyto test ours; projects, electronic circuits, to maintain equipment, among others. However, this power supply must have at least a voltage adjustment control, and at least a short circuit protection.
And this is the proposal of this circuit, a simple and very effective circuit, with protection against short circuit, and that brings in its output an adjustable voltage between, 1.25v to 33 volts, with a current of 3 Amps, which is enough for most of the projects, and still, this PS has protection circuit against short circuit and over-temperature protection.
The LM350IC is an adjustable three-pin positive voltage regulator capable of delivering 3.0 Amperes in an output voltage range of 1.2 V to 33 V. This voltage regulator is exceptionally easy to use and requires only two external resistors to adjust the output voltage.
Besides:
Internal Current Limiting
Thermal shutdown
Secure Area Compensation
What do the LM350 integrated circuit, an essentially explosion-proof component.
The LM350 serves a wide variety of applications:
Static Voltage Regulator for digital circuits
Stable Current Regulator
Variable Current Regulator
This device also does an especially simple adjustable switching regulator, a programmable output regulator, or connecting a fixed resistor between the setting and the output, the LM350 can be used as a precision current regulator:
Guaranteed 3.0 The output current
Adjustable output between 1.2 V and 33 V
Load Regulation Normally 0.1%
Line Regulation Normally 0.005% / V
Internal thermal overload protection
Temperature Short-Circuit Internal Current Limiting Current
Compensation of the safe area of the output transistor
Floating Operation for High Voltage Applications
Standard 3-way Transistor Package
Eliminates Socks Many Back Fix
The Circuit
The electric schematic diagram, it follows in Figure 2 below, is quite simple, first, we have the rectifier diode bridge KBL610 that is a bridge of 6 Amperes to 1000 Volts, however, you can use anyone that you have and that is above 4 Amperes over 50 Volts.
Diodes D2 and D3 are for the protection of the IC LM350, against short circuits, because when we start the Power Supply, and the capacitor C3 is totally discharged, and it becomes as a short-circuit for the IC.
The C1 capacitor is to attenuate the ripples interference and stability of the same. The C2 capacitor has the function of constancy to decrease Ripple, and stability of the power supply.
P1, is an analog potentiometer of 5K, if you don’t have the 5K you can put a 4.7K, which is more commercial. T1 is a transformer of at least 3 Amperes, with input according to your local network, which can be 220v or 110v depending on your region, and the transformer secondary is 25 Vac for the output of 33 Vdc.
Fig. 2- Adjustable Power Supply Schematic LM350
So you want to do a more powerful adjustable power supply, for example with 6 Amps, we have this adjustable module post in the link below:
Others .... Printed Circuit Board, tin, wire, etc.
We are offering to Download the link with the printed circuit board printing files, they are; Gerber, PDF layout, PNG, all the files with a direct link to Mega.
ATX Switched-Mode Power Supplies have some interesting features when compared to standard Switched Mode Power Supply (SMPS).
In the ATX power supply, there are different output voltages: + 12V, + 5V, +3.3V, -12V, -5V and 5VSB. There are some variations on these types of Power Supply, but in the general context, the pattern is this.
The way SMPS work is pretty much the same.
They control the output voltage by opening and closing the switching circuit so as to maintain the opening and closing time of this circuit, that is, the width of the pulses and their frequencies, to obtain the desired voltage.
There are separate processes for everything to work smoothly.
So let's see the modular diagram to unravel the steps of these processes so that we can step by step understanding.
This is the block in modules divided by steps, to improve our understanding.
There are 10 basic steps to running an ATX power supply, there are other underlying modules that are intrinsic in the steps, but, we'll not go as deep as it would be extremely great this Blogger, for those who want to watch the explanatory video with details in Portuguese. On the original post channel from YouTube.
Is through that stage that the voltage coming from your network, whether 110 or 220V AC should enter.
Transient Filter
This voltage goes through basic protection, the fuse, that if some step ahead short, the fuse opens, avoiding to burst everything ahead, and in the same line, we have the NTC (Negative Temperature Coefficient), It's a surge current limiter, in series with the electric circuit,
In it the value of ohmic resistance decreases as its temperature rises, its initial resistance is approximately 15 Ohms, which we can understand by the Ohms' law, the advantages one has in using it in series after the power supply switches it on lowers its resistance to approximately 0.5 Ohms.
EMI filters also exist, these are used to avoid high-frequency noise and a huge amount of harmonics generated by the switches that can propagate through the electrical network and cause interference in nearby electronic equipment.
Step 2 - Primary Rectification
Primary Rectification
In this stage we find the rectifier bridge or an arrangement formed by four common diodes, which has the function of rectifying a full-wave voltage, that is, rectifying an alternating electric current (AC), transforming it into a continuous electric current ( DC).
Step 3 - Filtration
Filtration
After rectification, the DC signal, Ripples (which are small variations, the capacitors are responsible for the filtering and stabilization IE, a decrease of these Ripples, in the rectified voltage, this voltage rises to something around 300V, which are used in the power switches, this part is fundamental to the correct stabilization of the source especially if its source is of high power.
Step 4 - Power Switches
Power Switches
These switches can be BipolarPower Transistors such as MOSFETs, or any other type, but they differ from ordinary transistors, by the type of operation in which these transistors work, these switching transistors dissipate less power than a common working transistor in a linear source because they work as a switch on / off at high speeds, depending on the design of the source, they suffer variations that are usually between 20Khz to 100kHz, they are directly responsible for the output voltage, and stability of that voltage, through of the commands received by the Control Circuit.
Step 5 - Output Transformer
Output Transformer
The transformer is a high-frequency CHOPPER TRANSFORMER, and they also work with alternating voltage, when passing through the switches the voltage will be a square wave AC type PWM, but with high frequency, not with the same frequency of 60Hz of the input voltage.
The switches work on two different levels, High and Low, when it is HIGH, the voltage goes through it normally, causing a constant voltage level in the input of the coil of the transformer, the action of these transistors, goes from HIGH to LOW very quickly.
This will induce the winding to have the necessary voltages according to the winding and frequency placed on these switches.
Step 6 - Fast Rectifier
Fast Rectifier
With the voltage generated by high-frequency switches, a diode is needed to meet this demand, so we have the high-speed diodes called SCHOTTKY DIODES or fast recovery diodes since ordinary diodes would not be able to work with high-frequency voltages.
Step 7 - Output Filters
Output Filters
The inductor - This has the function of eliminating the high-frequency harmonics so that they do not travel to the equipment that will be fed, imagine if these harmonics pass to a micro-controller for example, could cause undue loads and errors of reading in the control processes.
And the Capacitors - They are the ones that filter and stabilize the voltage at the output, avoiding ripples and instabilities at the output.
Step 8 - Driver Transformer
Driver Transformer
The driver transformer in this case is nothing less than the one responsible for traffic the information coming from the Integrated Circuit Controller, and pass these commands to the switches, so as to bring insulation or electrical decoupling between primary and secondary, in this topology there is a pair of transistors that also switch the Transformer Drive to receive these PWM pulses from the driver IC, passing this information to the power step we already saw in Step 4.
Step 9 - PWM control
PWM control
The brain of a switched source is its PWM controller, they are dedicated integrated circuits, to perform that work, but they do not work alone, there are also current sensors, which also vary from source to source, but it is very likely that you will find in its source the TL341IC, it has the aspect of a transistor, but, it is not a transistor, it is very popular for its cost-benefit.
This circuit is connected to the output of the power supply, receives Feedback, and directs the voltage information to the IC that controls the oscillator that generates a rectangular signal whose pulse width is controlled and sent to the Transformer Drive that sends these commands to the step of power.
If the power at the output to raise the voltage tends to drop, the circuit activates the instantaneous correction in the pulse width of the switching transistors and the voltage keeps stabilized.
Step 10 – Primary Power Supply VSB
Primary Power Supply VSB
VSB stands for Voltage Standby, which is technically a power supply that keeps its output active, whenever the source power cord is connected to the mains, its capacity is approximately 2 Amps, and this depends on the total power of the source, this active voltage line is to keep the circuit active and is necessary for when the power on button is activated through PSON, which is the start of the power supply, then the oscillator will activate the power line also powers the motherboard hardware to activate peripherals via software, keyboard, network, and so on.
If you have any questions, suggestions or corrections, please leave them in the comments and we will answer them soon.
Fig 1 – Stabilized Power Supply 13.8V High Current 10 Amps
This is an excellent and simple stabilized power supply of 13.8V and high current, 10 Amps. This power supply has great stability, and you can use it with a large number of projects, such as:
Power supply for Radio Amateurs, which need a high current and excellent stabilization to work well, batteries chargers, since, 13.8V is a good voltage to charge most batteries, automotive sound power supply, etc.
Finally, it can be used for countless types of projects, not to mention that its assembly is easy to build, using discrete components that are easy to acquire.
Miscellaneous …….. Printed Circuit Board, tin, wire, etc.
The Transformer
The power transformer must have a supply capacity of at least 10 Amperes, this taking into account that you want to use this circuit for 10A.
You may be using a power transformer with a smaller capacity that will not harm the circuit, just making it clear, that if a power transformer with a lower current is placed, for example, 5A, at the output you will have a maximum of 5A.
I said at most because, we know that there are losses due to dissipation, conversion, etc., but it’ll work, the voltage of the transformer must be at least 12Vac, and a maximum of 18Vac, for a more efficient operation.
We are offering to download the link with the printed circuit board printing files, they are; Gerber, PDF layout, PNG, all the files with a direct link to Mega.
So you want to do a more powerful adjustable power supply, for example with 
