Electronic Parts and Schematic Diagram: September 2010

The circuit is being powered by two 15V power supply for each channel, that is regulated by the combination of resistors R7-9 and Zener diodes D1-2. The frequency bandwidth is limited to a specific value due to the presence of low pass filter from R2 & C2 and high pass filter from R3 & C1. The total feedback of the circuit is concentrated on the positive non-inverting input of the IC1 that functions as differential amplifier. The node of R4-5 is applied with the feedback voltage from the output through R6. The current regulated by R10 & R14 across Q1-2 is 10mA as they operate in class A while in class AB, the power transistors Q8-11 operate in the output with a regulated constant current of 100mA each power transistor, done by trimmer TR1 and Q3. This will match the voltage drop at 27mV, higher than the provided voltage of R25-28.

A heatsink with sufficient dimension to provide cooling is placed above Q1-2-3-6-7 to maintain the possible thermic stability while the protection from reverse voltages from the load is performed by diodes D9-10.Additional fan can also be employed to suppress high temperature for efficient operation. The stability during high frequencies is sustained by the Zobel network consisting of R29 & C18. Due to capacitive load, the amplifier output is protected by a 1mm diameter 15-coil inductor L1 with R30 for square pulses passage.

Each power amplifier that is created will correspond to a transformer to handle large capacitors and provide proportional power. The transformer input is connected to the AC line which can incorporate delay circuit for protection from excessive supply. The cables that would carry the current to the amplifier should be appropriate enough.

Wednesday, September 1, 2010

1000 W Power Amplifier Schematic Diagram.

Download this schematic diagram.

Datasheet semiconductor component download.

1. BC546
2. BD681
3. MJE350
4. MJE340
5. 2SC5200
6. 2SA1943
7. 2SA1494
8. 2SC3858

The assemble cables for DC power supply and output transistors must be large, use size 1.5-3mm for large current passed. The supply used transformer with 20A/45Ct and at least 4x10000uf/80 volt capasitor. this circuit is able to supply power 10000watt therefore the power transistor will be very hot, give good cooling fan on the power transisitor

Transitor alternative to replacement of the 2SA1494 is 2SA1216 From SANKEN. The transistor has a 200-350 watt power dissipation of each pair so that for long-term operation of more durable. Keep in mind, usually sold a pair of power transistors with its complement, so you can not buy 2SC2922 alone without 2SA1216 or 2SA1494 without 2SC3858.

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.