Great Wall ATX-300P4-PFC computer power supply auxiliary circuit schematic

MOS power IC full range

inductance

SMD aluminum electrolytic capacitor

description

The following figure shows a complete switching power supply circuit. Its components mainly include switching oscillator circuit consisting of switching tube Q2 (C3866), starting resistors R10, R10A, R10B, R15 and switching transformer T3; automatic voltage regulation control The circuit consists of precision voltage regulator IC1 (TL431AC), optocoupler UI (P421), transistor Q4, resistors R16~R19, J2, etc.; overcurrent protection circuit (by transistor Q4, resistor R14, R13, capacitor C9, diode D5 , T3 N2 winding and photocoupler secondary photosensitive tube, etc.). The function of this circuit is different from that of ordinary switching power supply (it is placed on the same circuit board in the Great Wall ATX-300P4-PFC power supply), which can generate about 15V and stable 5V DC voltage during operation. The effect of these two sets of voltages is: 15V voltage is dedicated to the start voltage (standby) for the ATX power supply; 5V voltage is sent to the computer motherboard standby through the purple line end (10 5VSB). However, when the ATX power supply is controlled to start, the 15V voltage will not be effective.