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 for the 40 W single chip amplifier.

Constructing the power supply for this amplifier is simple. As shown on the schematic above you need to wire up a 18-0-18 (center tapped) transformer in order to get the recommended +/- 25V. Be very careful since this construction involves mains wiring.

1-chip 40 watt amplifier.

This is a compact, easy to build amplifier that uses one IC only but delivers 40 watts of audio power. It is ideal for amplifying audio from your mobile CD player or iPod. The chip being used here is the TDA1514 originally brought to the market by Phillips/Valvo. The best characteristics of this chip is its high output power and robustness. It is available in a 9-pin SIL plastic package with a metal mount.

Its package has a heat resistance of less than 1.5K/W. This means that the heatsink must have a heat resistance of only 3.8K/W when the chip reaches its maximum power dissipation of 19W (at Ub = +/-27.5V, Tu = 50⁰C).
One can see from the diagram that only a handful of passive elements are needed to build the chip into a powerful audio amplifier. The power supply as supplied must be able to deliver a current of at least 3 amperes. The standby current consumption is about 60 mA. The supply voltage must never go beyond 27.5 volts!

In building the circuit, keep the wires to the power supply and outputs as short as possible. The resistos R4 and R5 set the voltage gain at the feedback which, in this case, is between 20 and 46 dB.
For a single channel amplifier(mono), a 80 VA transformer (T1) should be sufficient. If you construct two channels (or stereo) amps, 120 VA is recommended. Capacitors Cx and Cy should be at least 4.700uF rated at 35V. It can be up to 10.000uF. Capacitors twice as large discharge slower giving better peak power potential resulting to better power output. Feel free to increase the capacitance but take note that you may not get much additional benefit for the price involved. Make sure they are connected the right way around too or they will blow and cause injury.


Download this schematic diagram.




Semiconductor datasheet component. (PDF Format)

1. TDA 1514