The mains power (220V AC) fed from N1 is filtered through
C1, L1, C2 and L2 then rectified by D1, D2, D3 and D4 and generates an output
at 00VDC. This 300VDC fed to T1 (pin2, pin4) which connects to TEA1523P (pin2),
then TEA1523Pwill automatically generate a 50 KHz square waveform, this 50 KHz
square waveform controls the ON/OFF between TEA1523Ppin2 and the ground. In
normal condition, T1 primary (between pin2 and pin4) will create a 50KHz square
waveform which is controlled by TEA1523P , this signal then fed to T1 and
generates 2 different potential voltages of 12V and 5V between pin17, pin14 and
pin16, pin14 respectively . The 12VDC and 5VDC then rectified by D7, D8, and D9
and then filtered by L3, L4, L5, C9, C10 and C1 1. The feedback voltage is controlled
by Ic3 TL431 and IC2 PC817. When the output voltage is higher than 5V , the
voltage at TL431(2.5V) is compared with R10 and send out a signal to 5L0380R,
the output square waveform then will change to adjust the output voltage, this
acts as a voltage stabilizer.
SMPS PROGRAMMABLE SHUNT REGULATOR.
The TL431/TL431A are three-terminal adjustable regulator
series with a guaranteed thermal stability over applicable temperature ranges.
The output voltage may be set to any value between VREF (approximately 2.5 volts)
and 36 volts with two external resistors. These devices have a typical dynamic
output impedance of 2.0W
Active output circuitry provides a very sharp turn-on characteristic
making these devices excel lent replacement for zener diodes in many applications.
POWER SUPPLY FAULT TRACING FLOW CHART
CLICK ON THE PICTURES TO MAGNIFY
