12-1) Source Power Circuit; 12-2) Oscillation Circuit - Samsung RB215BSSB Service Manual

OPERATION PRINCIPLES BY PARTS OF CIRCUIT

12-1) SOURCE POWER CIRCUIT

Power
1) When the power is supplied,AC voltage stepped down on the 2nd transformer flows between ①and
③at about AC 16V and changes to DC voltage when it goes through the diode D101 and D108,and
constant 12V will be output via regulator REG1(7812).And,it will supply DC5V to MICOM and power
to other circuits via regulator REG2 (MC7805ACT),and make entire PCB operate.

12-2) OSCILLATION CIRCUIT

1) It is an Oscillation Circuit for synchronism clock generation and time calculation on the information
sending &receiving of the MICOM internal logic elements and when specifications for Resonator
change,the timing system of MICOM changes resulting in errors. (Rated parts must be used)
Vcc(DC 5V)
+12V(DC 12V)
Circuit
MICOM POWER AND SENSORS
RELAY,PANEL DRIVING CIRCUIT
Terminal
Xin(#19)
Xout(#18)
47
Oscillation Freq.
8MHz
8MHz