Many people, acquiring new computer equipment, throw their old system unit into the trash. It's pretty short-sighted, because it may still contain workable components that can be used for other purposes. In particular, we are talking about a computer power supply, from which you can.
It is worth noting that the cost of making your own hands is minimal, which allows you to significantly save your money.The computer power supply is a voltage converter, respectively +5, +12, -12, -5 V. By certain manipulations, you can make a completely working charger for your car from such a PSU. In general, there are two types of chargers:
Chargers with many options (starting the engine, exercising, recharging, etc.).
Battery charger - such chargers are needed for cars that have small mileage between runs.We are interested in the second type of chargers, because most vehicles are operated for short runs, i.e. the car was started, drove a certain distance, and then drowned out. Such operation leads to the fact that the car battery runs out of charge rather quickly, which is especially typical for winter time. Therefore, such stationary units are in demand, with the help of which you can very quickly charge the battery, returning it to working condition. The charging itself is carried out using a current of about 5 Amperes, and the voltage at the terminals ranges from 14 to 14.3 V. The charging power, which is calculated by multiplying the voltage and current values, can be provided from the computer power supply, because its average power is about 300-350 W.
Converting a computer power supply into a charger
Today, the cost of a laboratory power supply is approximately 10 thousand rubles. But it turns out that there is an option for converting a computer power supply into a laboratory one. For just a thousand rubles, you get short circuit protection, cooling, overload protection and several voltage lines: 3V, 5V and 12V. However, we will be modifying it to have a 1.5V to 24V range, which is ideal for most electronics.
I think this is the best way to convert a computer power supply to 24 volts, given that I was able to make it a reality with my own hands at only 14 years old.
WARNING: We are working with current here, be careful and follow the safety measures!
You will need:
- roulette
- screwdriver
- Computer power supply (recommend 250W+) and cable for it
- Wire Latches
- soldering iron
- 10 ohm resistor 10W or more (some newer PSUs don't work properly with no load, so the resistor should provide it)
Not necessary:
- switch
- 2 LEDs of any color (red and green are best)
- If you are using LEDs, you will need 1 or 2 330 ohm resistors,
- Heat shrink
- Outer case (you can put everything in the original case, or you can take another one).
Depending on which method you use for a regulated computer PSU (more on this later):
- Terminal blocks
- Drill
- Resistor 120 ohm
- Variable resistor 5 kΩ
- Connectors
- Clips "crocodile"
Step 1: Gathering and preparing the power supply
Warning: MAKE SURE THE POWER SUPPLY IS NOT CONNECTED BEFORE YOU START
Capacitors can electrocute, which is quite painful. Let the power supply lie down for a few days to discharge it, or connect a 10 ohm resistor to the red and black wires.
If you hear a buzzing sound when you turn on the power, it means there is a short circuit somewhere or some other serious problem. If you hear a buzzing sound (not from a soldering iron) while soldering, it means that the power supply is connected. Remember that if a unit that is connected to power is turned off with a button, there will still be current in it.
Okay, let's take the power supply out of the computer. It is usually attached with 4 screws to the back of the case. Take the wires out of the hole, then group them by color and cut off the ends.
By the way, you just voided your warranty.
Step 2: Making the wiring
Now let's get to the tricky part, where you need to add LEDs, switches and other such details. We have many wires of each type, so I recommend using 2-4 wires. Some people go through everything inside the box, but I did everything outside. It depends on which method you use in the next step.
If you want to add a standby indicator or power on indicator, you will need an LED (I recommend red, but not required) and a 330 ohm resistor. Solder the black wire to one end of the resistor and the short end of the LED to the other. The resistor will reduce the voltage so as not to damage the LED. Before soldering, put on a small piece of heat shrink to protect the pins from shorting. Solder the purple wire to the longer leg and when you apply power (not including the block) the LED should light up.
You can also install another LED for the switched on power supply (I recommend green). Some say to use the gray wire to power the LED, but then you need another 330 ohm resistor. I just connected it to the orange 3.3V wire.
If you are using the gray wire method:
Before soldering it, put on another piece of heat shrink to prevent a short circuit. Solder the gray wire to one end of the resistor and the other end of the resistor to the longer leg of the LED. Solder the black wire to the short leg.
When using the orange 3.3V wire:
Before soldering it, put on another piece of heat shrink to prevent a short circuit. Solder the orange wire to the longer leg of the LED and the black wire to the shorter leg.
Now to the switch: if there is already a switch on the back of your power supply, this item will not be very useful to you. Connect the green wire to one pin on the switch and the black wire to the other. If you don't want to use the switch, just connect the green and black wires.
You can also use a 1A fuse. All you have to do is cut the black wires about halfway down and connect them to the fuse in the holder.
Some power supplies need a load to work properly. To provide this load, solder the red wire to one end of the 10 ohm/10 watt resistor and the black wire to the other. This way the block will think that it is doing something.
If you do not understand anything, take a look at the diagram that I have attached. It shows how to connect wires. I will talk about this in the next step. It shows the way with the gray wire to the LED (but you can use the orange one as above) and also shows the wiring for the high ohm resistor.
Step 3: Let's start the current!
In the tutorials I've read, there are many different ways to connect connectors to connect your devices to power. We'll start with the best and work our way down to the worst.
Some tutorials will tell you how to assemble all the parts inside the case, but this is dangerous and will lead to excessive heat and breakage. I recommend using external mounting.
Adding a Variable Resistor
I personally think this is the best method, as it can provide any voltage from 1.5V to 24V. The reason it's 22V and not 12V is because it uses the blue wire, which is -12V, not the regular ground (black wire).
We will need:
- Voltage regulator LM317 or LM338K
- Capacitors 100nF (ceramic or tantalum)
- Capacitors 1uF Electrolytic
- Power diode 1N4001 or 1N4002
- Resistor 120 ohm
- Variable resistor 5 kΩ
First build the circuit from the main picture and connect your +12 and -12V lines. Then drill holes in the power supply or outer case to install the variable resistor. All other details must be inside. Now I suggest adding two terminal blocks so you can connect devices directly. You can also connect crocodiles to them. When you turn the variable resistor, the voltage should be between 1.5V and 24V.
NOTE. There is a typo on the main image, which should be taken into account: + 24V instead of 22V. If you have an old voltmeter, you can connect it to the circuit to monitor the output voltage.
Connectors
Now you need to install connectors for connecting equipment. Drill holes for them (make sure to wrap the PCB in plastic, as metal fragments can short it out), and then check if they fit by inserting the connectors and tightening the bolt. Choose how much voltage should go to each connector and how many connectors to insert. Designations of wires by colors:
- Red: +5V
- Yellow: +12V
- Orange: +3.3V
- Black: Earth
- White: -5V
Above is an image using the connector method.
Crocodile Clips
If you don't have much experience or don't have the above parts and for some reason you can't buy them, you can just connect whatever voltage lines you want to the crocodile clips. If you choose this option, I recommend using insulation to prevent short circuits.
- Don't be afraid to add ingredients to the box: LEDs, stickers, etc.
- Make sure you are using an ATX power supply. If it's an AT or older power supply it will most likely have a different color scheme for the wires. If you don't have wiring data, don't even start any work or you'll just break your block.
- If the LED on the front panel does not light up, then the legs are connected incorrectly. Just swap the wires and it should light up.
- Some modern PSUs have a "Regulator Feedback" wire that must be connected to a power source for the unit to operate. If the wire is grey, connect it to the orange wire, if it is pink, connect it to the red wire.
- A high power power resistor can get quite hot; you can use a heatsink to cool it down, but make sure it doesn't create a short circuit.
- If you decide to mount the parts inside the case, the fan can be installed outside to free up some space.
- The fan can be noisy because it is powered by 12V. Since this is not a computer that gets very hot, you can cut the red fan wire and connect the orange 3.3V. Monitor the temperature after that. If it is too large, reconnect the red wire.
Congratulations! You have successfully made your power supply.
In this article I will tell you how to make a laboratory power supply very useful for any radio amateur from an old computer power supply.
You can buy a computer power supply very cheaply at a local flea market or beg from a friend or acquaintance who has upgraded his PC. Before you start working on a PSU, you should remember that high voltage is life-threatening and you need to follow safety rules and exercise extra caution.
The power supply we made will have two outputs with a fixed voltage of 5V and 12V and one output with an adjustable voltage of 1.24 to 10.27V. The output current depends on the power of the computer power supply used and in my case is about 20A for a 5V output, 9A for a 12V output, and about 1.5A for a regulated output.
We will need:
1. Power supply from an old PC (any ATX)
2. LCD voltmeter module
3. Radiator for the microcircuit (any suitable size)
4. LM317 chip (voltage regulator)
5. electrolytic capacitor 1uF
6. Capacitor 0.1uF
7. LEDs 5mm - 2 pcs.
8. Fan
9. Switch
10. Terminals - 4 pcs.
11. Resistors 220 Ohm 0.5W - 2 pcs.
12. Soldering accessories, 4 x M3 screws, washers, 2 x self-tapping screws and 4 x 30mm brass standoffs.
I want to clarify that the list is indicative, everyone can use what is at hand.
General characteristics of the ATX power supply:
ATX power supplies used in desktop computers are switching power supplies using a PWM controller. Roughly speaking, this means that the circuit is not classical, consisting of a transformer, rectifierand voltage stabilizer.Her work includes the following steps:A) The input high voltage is first rectified and filtered.
b) At the next stage, a constant voltage is converted into a sequence of pulses with a variable duration or duty cycle (PWM) with a frequency of about 40 kHz.
V) In the future, these pulses pass through a ferrite transformer, while the output is relatively low voltage with a sufficiently large current. In addition, the transformer provides galvanic isolation between
high and low voltage parts of the circuit.
G) Finally, the signal is rectified again, filtered and fed to the output terminals of the power supply. If the current in the secondary windings increases and the PSU output voltage drops, the PWM controller corrects the pulse width andthus, the output voltage is stabilized.
The main advantages of such sources are:
- High power with small dimensions
- High efficiency
The term ATX means that the motherboard controls the power supply. To ensure the operation of the control unit and some peripheral devices, even in the off state, a standby voltage of 5V and 3.3V is supplied to the board.
To disadvantages include the presence of impulse, and in some cases, radio frequency interference. In addition, during operation of such power supplies, fan noise is heard.
Power supply power
The electrical characteristics of the power supply are printed on a sticker (see figure) which is usually located on the side of the case. From it you can get the following information:
Voltage - Current
3.3V - 15A
5V - 26A
12V - 9A
5 V - 0.5 A
5 Vsb - 1 A
For this project, voltages of 5V and 12V are suitable for us. The maximum current, respectively, will be 26A and 9A, which is very good.
Supply voltages
The output of the PC power supply consists of a bundle of wires in various colors. The color of the wire corresponds to the voltage:It is easy to see that in addition to connectors with supply voltages of +3.3V, +5V, -5V, +12V, -12V and ground, there are three more additional connectors: 5VSB, PS_ON and PWR_OK.
Connector 5VSB used to power the motherboard when the power supply is in standby mode.
PS_ON connector(power on) is used to turn on the power supply from standby mode. When a voltage of 0V is applied to this connector, the power supply turns on, i.e. to run the power supply without a motherboard, it must be connected tocommon wire (ground).
POWER_OK connector in standby mode has a state close to zero. After the power supply is turned on and the required voltage level is formed at all outputs, a voltage of about 5V appears on the POWER_OK connector.
IMPORTANT: In order for the power supply to work without connecting to a computer, you must connect the green wire to a common wire. The best way to do this is through a switch.
Power Supply Upgrade
1. Disassembly and cleaning
It is necessary to disassemble and clean the power supply well. The best thing for this is a vacuum cleaner turned on by blowing or a compressor. You need to be extra careful, because. even after disconnecting the power supply from the mains, life-threatening voltages remain on the board.
2. Prepare the wires
We unsolder or bite off all the wires that will not be used. In our case, we will leave two red, two black, two yellow, lilac and green.
If there is a powerful enough soldering iron, we solder the extra wires, if not, we bite off with wire cutters and insulate with heat shrink.
3. Making the front panel.
First you need to choose a place to place the front panel. The ideal option would be the side of the power supply from which the wires exit. Then we make a drawing of the front panel in Autocad or another similar program. Using a hacksaw, a drill and a cutter, we make a front panel from a piece of plexiglass.
4. Rack placement
According to the mounting holes in the drawing of the front panel, we drill similar holes in the power supply case and fasten the racks that will hold the front panel.
5. Voltage regulation and stabilization
To be able to adjust the output voltage, you need to add a regulator circuit. The famous LM317 chip was chosen because of its ease of inclusion and low cost.The LM317 is a three-terminal adjustable voltage regulator capable of providing voltage regulation in the range from 1.2V to 37V at a current of up to 1.5A. The chip wiring is very simple and consists of two resistors that are needed to set the output voltage. Additionally, this microcircuit has protection for overheating and overcurrent.
The switching circuit and pinout of the microcircuit are shown below:
Resistors R1 and R2 can adjust the output voltage from 1.25V to 37V. That is, in our case, as soon as the voltage reaches 12V, then further rotation of the resistor R2 will not regulate the voltage. In order for the adjustment to take place over the entire range of rotation of the regulator, it is necessary to calculate the new value of the resistor R2. To calculate, you can use the formula recommended by the chip manufacturer:
Or a simplified form of this expression:
Vout = 1.25(1+R2/R1)
The error in this case is very low, so that the second formula can be used.
Taking into account the obtained formula, the following conclusions can be drawn: when the variable resistor is set to the minimum value (R2 = 0), the output voltage is 1.25V. As the resistor knob is turned, the output voltage will increase until it reaches the maximum voltage, which in our case is slightly less than 12V. In other words, our maximum should not exceed 12V.
R2=(Vout-1.25)(R1/1.25)
R2=(12-1.25)(240/1.25)
R2=2064 Ohm
The standard resistor value closest to 2064 ohms is 2k ohms. The resistor values will be as follows:
R1= 240 Ohm, R2= 2 kOhm
This completes the calculation of the controller.
6. Assembly of the regulator
We will assemble the regulator according to the following scheme:
Below is a schematic diagram:
The assembly of the regulator can be done by surface mounting, soldering the parts directly to the pins of the microcircuit and connecting the remaining parts with wires. You can also etch a printed circuit board specifically for this or assemble a circuit on a mounting board. In this project, the circuit was assembled on a circuit board.
You also need to attach the stabilizer chip to a good radiator. If the radiator does not have a screw hole, then it is made with a 2.9mm drill, and the thread is cut with the same M3 screw that will be used to screw the microcircuit.
If the heatsink is screwed directly to the power supply case, then it is necessary to isolate the back of the chip from the heatsink with a piece of mica or silicone. In this case, the screw with which the LM317 is fastened must be insulated with a plastic or getinax washer. If the radiator does not come into contact with the metal case of the power supply, the stabilizer chip must be put on thermal paste. In the figure you can see how the radiator is attached with epoxy resin through a Plexiglas plate:
7. Connection
Before soldering, you must install the LEDs, switch, voltmeter, variable resistor and connectors on the front panel. The LEDs fit perfectly into holes drilled with a 5mm drill, although they can be additionally secured with superglue. The switch and voltmeter are held firmly on their own latches in precisely cut holes. The connectors are fastened with nuts. Having fixed all the details, you can start soldering the wires in accordance with the following scheme:
To limit the current, a 220 ohm resistor is soldered in series with each LED. The joints are insulated with heat shrink. The connectors are soldered directly to the cable or through adapters. The wires must be long enough to remove the front panel without any problems.
They often ask questions and complain about failures. To show that the alteration is really possible and it is not difficult at all, we have prepared another article, with illustrations and explanations.
Recall that you can remake any blocks, both AT and ATX. The first differ simply in the absence of a duty room. As a result, the TL494 in them is powered directly from the output of the power transformer, and, again, as a result, when adjusted at low loads, it simply will not have enough power, because. the duty cycle of the pulses on the primary transformer will be too small. The introduction of a separate power supply for the microcircuit solves the problem, but requires additional space in the case.
ATX power supplies here compare favorably in that nothing needs to be added, you just need to remove the excess and add, roughly speaking, two variable resistors.
On alteration - ATX MAV-300W-P4 computer power supply. The task is to convert it into a laboratory 0-24V, in terms of current - how it will turn out. They say that it is possible to receive 10A. Well, let's check.
Click on the diagram to enlarge
The power supply circuit is easy to google, but we can do without it, because we know that from the TL494 we need the inputs of both comparators, and these are pins 1, 2, 15, 16, and their common output 3, which is usually used for correction. We also release pin 4, since it is usually used for various protections. However, we leave the capacitor C22 and the resistor R46 hanging on it for a smooth start. We solder only the D17 diode, disconnecting the voltage monitor from the TL-ki.
Add resistors, regulators, shunt. As the latter, two 0.025 ohm SMD resistors are used in parallel, which are included in the gap of the negative track from the transformer.
We connect the power supply to the network through a 200W incandescent lamp, which is designed to protect against breakdown of power transistors in case of an emergency. At idle, the voltage is perfectly regulated from almost 0 to 24 volts. What happens under load? We connect several powerful halogens and see that the voltage is already regulated up to 20 volts. This is to be expected since we are using 12V windings and a mid-point rectifier. On a powerful load, PWM is already at the limit and it is no longer possible to get more.
What to do? You can simply use the power supply to power not very powerful loads. But what to do if you really want to get the coveted 10 amps, especially since they are just declared on the power supply label for the 12 volt line? Everything is very simple: we change the rectifier to a classic bridge of four diodes, thereby increasing the voltage amplitude at its output. To do this, you need to install two more diodes. The diagram shows that such diodes were just installed, these are D24 and D25, along the -12 volt line. Unfortunately, their location on the board is unsuccessful for our case, so we will have to use diodes in "transistor" cases and either install separate heatsinks on them, or attach them to a common heatsink and solder them with wires. The requirements for diodes are the same: fast, powerful, for the required voltage.
With a converted rectifier, the voltage, even with a powerful load, is regulated from 0 to 24 volts, current regulation also works.
It remains to solve one more problem - the power supply of the fan. It is impossible to leave the power supply without active cooling, because the power transistors and rectifier diodes heat up according to the load. Normally, the fan was powered by a +12 volt line, which we turned into an adjustable one with a voltage range slightly wider than the fan needs. Therefore, the simplest solution is to feed it from the duty room. To do this, we replace the capacitor C13 with a more capacious one, increasing its capacity by 10 times. The voltage at the cathode D10 is 16 volts, and we take it for the fan, only through a resistor, the resistance of which must be selected so that the fan has 12 volts. As a bonus, you can bring a good five-volt + 5VSB power line from this PSU.
The requirements for the inductor are the same: with the DHS we wind all the windings and wind a new one: from 20 turns, 10 wires with a diameter of 0.5 mm in parallel. Of course, such a thick core may not fit into the ring, so the number of parallel wires can be reduced according to your load. For a maximum current of 10 amps, the inductance of the inductor should be in the region of 20uH.
A shunt built into an ammeter can be used as a shunt, and vice versa - a shunt can be used to connect an ammeter without a built-in shunt. The shunt resistance is around 0.01 ohm. By decreasing the resistance of the resistor R, you can increase the range of voltage adjustment upwards.
Regulated power supply from an ATX computer power supply
(ATX is with a duty room)
There is a lot of information on the Internet about the alteration of the power supply (PSU) from a computer type AT and ATX. But I decided to highlight the most important information and compile my own article from everything that I found on the Internet specifically for the site site
First of all, we look at the quality of the assembled BP by the “Chinese)))”. A normal PSU should look something like this
What you should pay attention to is the high-voltage part of the PSU. There should be smoothing capacitors and chokes (They smooth out the impulse surge into the network), it should also be at least 2A on the diode bridge and capacitors after the bridge (I usually set 680 uF / 200V or 330 uF / 200V based on the power demand), if you want to get 300 W (30V / 10A) from the PSU, then you need to set at least 600 uF.
Naturally, you need to pay attention to the Q1-2 power switches and the C8R4 damper circuit. Q1-2 is usually set to MJE13007- MJE13009 (There are also articles about altering the circuit for field-effect transistors). C8R4 damper circuit, I noticed that when adjusting the PSU R4 of this circuit it gets very hot, I decided to select C8.
Further, the alteration of the PSU must be continued with a careful study of the circuit of the PSU itself (although the circuits are almost the same, but still worth it), all subsequent work depends on this. It is necessary to pay special attention to several things in studying the circuit: the protection system (4th pin of the PWM controller), the Power Good System (it can simply be removed), the current error amplifier (15,16,3 PWM pins), the voltage error amplifier (1,2,3 PWM pins) and also the power supply output circuit (Here you will need to redo everything).
Let's consider each point in order.
Protection systems (4th conclusion) The scheme is taken from Golubev's article drive2.ru
This is a typical scheme (although there are others) of what is happening here. With an increase in the load on the inverter above the allowable one, the pulse width at the middle terminal of the isolation transformer T2 increases. Diode D1 detects them and negative voltage is increased across capacitor C1. Having reached a certain level (approximately -11 V), it opens the transistor Q2 through the resistor R3. A voltage of +5 V through an open transistor will go to pin 4 of the controller, and stop the operation of its pulse generator.
All diodes and resistors are soldered from the circuit, suitable from the secondary rectifiers to the base Q1, and a zener diode D3 is installed for a voltage of 22 V (or higher voltage), for example, KS522A, and resistor R8.
In the event of an emergency increase in voltage at the output of the power supply above 22 V, the zener diode will break through and open transistor Q1. That, in turn, will open the transistor Q2, through which +5 V will be supplied to the output 4 of the controller, and stop the operation of its pulse generator.
If you do not need protection, then you can simply unsolder everything and close pin 4 to the case through a resistor (the diagram will be below).
Power System Good - I usually just drink it.
Current error amplifier (15,16,3 PWM pins) This is the output current adjustment. But this does not mean that you can not worry about protection from short circuit.
Voltage error amplifier (1,2,3 PWM pins) - This is the output voltage adjustment.
So is voltage regulation.
(Here is the protection scheme)
This circuit is drawn without current regulation.
The 14th PWM pin is the reference voltage. And conclusions 2.1 are the voltage inputs of the op-amp.
All regulation is carried out using voltage dividers. At pin 2, we apply an exemplary voltage from the 14th pin through a divider R5R6 of 3.3 kOhm. This divider is designed for a voltage of 2.4V. Next, we need to apply the output voltage from the secondary circuit to the first PWM output and also through the divider, but already through the variable. Variable resistor R1 and constant R3. On my PSU came out adjustment from 2-24 volts. The output voltage also depends on the power transformer and the output circuit, but more on that later. Let's return to our Shimka, the voltage regulation setting does not end there. We also need to pay attention to the 3rd PWM output, this is the output of the op-amp and it needs to make the OOS on the 2nd leg for smooth adjustment and remove the noise, crackling and other unpleasant sound of the transformer. I have it assembled on C4R3 and C1. Although C4R3 is often enough, but due to the many varieties of "Chinese manufacturers", you sometimes need to add a conder, usually 1 microfarad is enough, but sometimes it reaches 5 microfarads.
Chains C4R3 and C1 must be selected so that there is no noise in the tr-re, but if it still remains, then you need to pay attention to the secondary circuit choke, there is a core violation, but we'll talk about that later.
Yes, about protection, I removed it here and put a 2 kOhm resistor R4.
Now about the current regulation
In principle, current regulation is also voltage regulation. With the help of a divider, but only here the reference voltage is already changing and the voltage drop on the ammeter (or shunt) is being monitored. In principle, there is nothing new about voltage regulation, only C1 is necessary and it may need to add a resistor in series, but this already depends on PWM and Tr-ra.
The general adjustment scheme is 100% workable, proven practice, if your circuit does not work stably or not quite correctly, then you need to: 1. Choose the ratings for your PWM and tr-r, 2. Look for errors in the assembly and modify. Again, I repeat in practice, it has shown that Chinese PWM and PSU as a whole react to changes in circuits in different ways. Everything needs to be set up by selection and calculation.
In the ATX PSU, the PWM and isolation transformer are powered from the Standby power supply, it can reach 25 V and is fed into the 12 PWM output circuit. Many people think that the diode in the secondary circuit of the Power TR-RA going to the 12th pin should be removed. I think it's better to leave this circuit, it gives additional confidence in the preservation of the power switches when they fail the standby power supply.
Now about the secondary circuit
The best conversion scheme seemed to me S. Golubeva (Driver2.ru)
Although the fan cannot be hung on a five-volt winding, because the voltage will also change there, and there is still no feedback from the PWM, and therefore, yes, with a load with a current of 0.15A, the voltage will drop significantly.
Now about the output voltage circuit itself. It makes no sense to change the pinout of the tr-ra and install a diode bridge. Because voltage increases and power decreases. Therefore, I prefer such a scheme, and then there are fewer alterations. Rectifier diodes D3 must be for a current of at least 10 A and a reverse voltage of at least 200 volts. These can be STPR1020CT, F12C20.ER1602CT. Diode D4, this is (as I call it) the auxiliary power supply circuit for PWM and Protection Vcc and Vdd. The ring inductance L1, if desired, you can leave the old one (Unless of course it works fine), but I rewind the same wire + wire from a five-volt circuit. Inductance L2 is usually left unmeasured. Capacitors C5C6 should not be set with a value of more than 2200 microfarads, it makes no sense. I usually put on 1000 microfarads and it's enough. Non-polar C4C7 can be raised to 1 microfarad if desired, but I also did not see much difference. But the resistor R5 should not be set less than 300 ohms, it will simply warm up at a voltage of more than 10 V, but not more than 500 ohms. This resistor balances the PSU so to speak.
That's actually all the most important thing in the alteration of the PSU.
Again, I focus on the fact that not all PSUs are easily and simply amenable to alteration and tuning. Therefore, you need to carefully study the diagram and information on the alteration.