Power Supply - Samsung S3F84B8 Design Manual

S3F84B8_ALL-IN-ONE IH COOKER_AN_REV 0.00

2.2 POWER SUPPLY

Figure 2-2 shows the circuit diagram for power supply.
D6
AC_L
220 VAC
D7
1N4007
D1
AC_N
1N4007 1N4007
The power circuit contains a transformer, an SMPS primary switcher, and a +5V DC regulator. After passing
through a half-wave rectifier and an LC filter, the 220V AC power enters the primary side of transformer.
Thereafter, VIPER12 and 78L05 produce stable +18V DC power for the transistors and +5V DC power for the
MCU and other devices.
L1
330uH
R1
100K/0.5W
D2
C2
+
UF4007
4.7uF/450V
Figure 2-2
T1
1 5
D7 UF4007
6
C1
4 8
102/1KV
EE-19
U1
8 1
D4 S1
7 2
D3 S2
6 3
D2 FB
5 4
D1 VDD
VIPER12A
Power Supply Circuit
2-6
2 HARDWARE IMPLEMENTATION
D4 UF4007 +18V
C6
+
100uF/25V
Z1 C21
+
18V UF4007 100uF/25V
D5
+ C8
C3 10uF/50V
104
78L05
1 +5V
VIN
3
VOUT
2 C13
+
GND
100uF/16V
IC1