Toshiba TDP-ST20E Service Manual page 54

d) Over Voltage Limit
Output voltage is detected by winding voltage of B1-B2 (T101).
This voltage is same as Vcc of
IC101 (pin 6). If output voltage becomes over voltage condition, pin 8 of IC101 to be pulled up through zener
diode ZD104, then power supply is shut down .(Latch)
e) Over Heat Protection
Over heat protection is detected Soldering parts temperature of Q1,Q2 (MC102) by TH102.
At abnormal condition (ex. Over-load or fan-lock ) when over temperature from
power supply shall be shut downed.
5) Secondary rectifier circuit
The cathode voltage of D202 is pulsating. D202,C203 and C204, which smooth out the pulsation to
make a ripple voltage lower through LC filter at L201 and C208.
6-11
Chapter 6
setting temperature,