200W ATX PC Power Supply Electronic Circuit.

Download this schematic diagram.




Datasheet semiconductor component. (PDF Format)

1. IN5406
2. 2SC4242
3. FR155
4. 2SC945
5. 2SA733
6. 2SC3457
7. LM7805
8. TL494
9. LM393
10. TL431C

Here I bring you wiring diagram of PCs power supply of DTK company. This power supply has ATX design and 200W performance. I was drawed diagram, when I repaired this power supply.

This power supply circuit uses chip TL494. Similar circuit is used in the most power supplies with output power about 200W.Device use push-pull transistor circuit with regulation of output voltage.

Line voltage goes through input filter circuit (C1, R1, T1, C4, T5) to the bridge rectifier. When voltage is switched from 230V to 115V, then rectifier works like a doubler. Varistors Z1 and Z2 have overvoltage protect function on the line input.
Thermistor NTCR1 limits input current until capacitors C5 and C6 are charged. R2 and R3 are only for discharge capacitors after disconnecting power supply. When power supply is connected to the line voltage, then at first are charged capacitors C5 and C6 together for about 300V.
Then take a run secondary power supply controlled by transistor Q12 and on his output will be voltage. Behind the voltage regulator IC3 will be voltage 5V, which goes in to the motherboard and it is necessary for turn-on logic and for "Wake on something" functions.
Next unstabilized voltage goes through diode D30 to the main control chip IC1 and control transistors Q3 and Q4. When main power supply is running, then this voltage goes from +12V output through diode D.

Power Supply 1.3 - 32 V / 5A with Short Circuit Protection

This is a very easy to build power supply that is based on LM338 5A adjustable voltage regulator. I am using the supply for a long time, have no problem yet. Only current adjust is missing but I overcome this situation by using an LCD panel ampermeter. There is no PCB for the circuit. I took a 3x16 copper plate and strip the unused areas by a knife. If you want you can use analog meters instead of LCD panels.

Download this schematic diagram.

Download datasheet semiconductor component. (PDF Format)

1. LM338

2. IN4002

Notes:

1. Use thick wires for connections.
2. When connecting the LM338 to the heatsink use thermal paste.
3. Use external supplies for LCD panels. They can be 9V batteries. The panels I use draws 1mA current and the batteries last sufficiently long time. If you have small transformers which can supply regulated 9V, you can use them. You need separate transformers for each panel!
4. The transformer should be 100 Watt but if you don't need high current you can try transformers that you already have. (I can draw 6A from 100Watt transformer.)
5. If you have multi winding transformer you can use the diode connections shown in schematic. Diodes must be 10-15 A.
6. Be careful while connecting LM338. Don't put it inverse.
7. Output of your transformer mustn't exceed 25V AC...