Circuit Details; Power Supply Part; Reset Circuit Part - Samsung RL33EBMS Service Manual

6. CIRCUIT DETAILS

6-1 Power Supply Part

Power supply
Vcc (DC 5V)
Vcc (DC 12V)
The AC input voltage will be stepped down by the transformer and be converted into the DC voltage
by the rectifying circuit (D101-104). The 1000F/35V wave filter capacitor will be used to filter out the
residue AC voltage and the manostat 7812 is used to output the steady 12V DC voltage that will be
used as the control voltage of the relay and display. The 12V DC voltage will be regulated by the
manostat 7805 to output the steady 5V voltage, which will be used as the output voltage of the chip
peripheral circuit and various signals (sensor, switch) .

6-2 Reset Circuit Part

Vcc
C203
104
The reset circuit part enables the system program to return the system that meets power trouble
or abrupt power-off to the initial state by the memory of the core chip. At the very beginning of
the power-on, the reset chip voltage is LV, and becomes HV after normal operation.
7
5
C105 C105
D101-104
104 104 1000uF
In4007
Applied circuit
Chip peripheral circuit and sensor
Control voltage of the display and relay
Ic02
I
5195A
G
17
C101 C801
104
O
C202
104
C802
104
RESET
18
21
VSS/ASS