Circuit Descriptions; Division Of Power Supply; Division Of Reset Circuit - Samsung SRL3928B(A) Service Manual

8. Circuit Descriptions

8-1. Division of power supply

Power supply
Vcc (DC 5V)
Vcc (DC 12V)
AC inputed power is decompressed through DC-TRANS and the reduced volatage is converted to the DC
voltage through rectifying DIODE. Then it becomes flat through 1000 F/35V CAPACITOR and through
REGULATOR 7812, stabilized DC 12V output comes and it is used as power source for RELAY and
DISPLAY.Also from this 12V, stabilized 5V output comes through REGULATOR7805 and used as power
source for MICOM auxiliary circuit and various signals(SENSOR, S/W).

8-2. Division of RESET Circuit

Division of RESET circuit makes it possible that programed function of system is set to be initial state
by initializing various parts such as RAM in MICOM when power is impressed or instantaneous
electricity failure is occurred. RESET voltage at the impressed moment of power is maintained as
LOW state for a few seconds and High under normal working condition.
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Auxiliary power supply of MICOM and sensing part of SENSOR
LED DISPLAY working part, RELAY working
Used circuit
Samsung Electronics