Instruction manual

9. Technical Board Information
9.1.4 OEM Power Board
Block diagram
OEM Power Board
IC7
DC 380V from PFC
5
4
3
2
F
S
X
L(M)
D
7
1
C
3
T3
+B
COL
1
5
4
AUX
GND
D25
C85
1
2
4
3
ISO5
1
2
4
3
ISO6
IC9
Linear regulator
D21
15V
D
2
2
5V
IC10
Linear regulator
D
2
6
GND
3.3V
IC13
TL431CLP
IC500
>>Input
OV/UV
Protec
Output
V
9
12
16
1
5V from Standby
-5V
IC11
Linear regulator
D
2
4
GND
10
13
Image 9-6
Block diagram OEM power board
Description
The OEM power board repeats operation which turns on and off at pin 7 pf IC12, and the pulse appears in secondary sides through
the converter transformer T3. At the time, the voltage of 3.3V at the secondary side is detected by IC13, the negative feedback to
IC12 is carried out at photo coupler ISO5 and then the voltage is stabilized.
Other outputs are determined by the turn ratio of secondary side of T3, and the voltage rectified, smoothed through the series
regulators (-5V is stablized at IC
11, 5V is stabilized at IC10, 15V is stabilized at IC9). The voltage rectified and smoothed by D25
and C85 at primary windings of T3 is supplied as a power supply voltage of IC12 on primary side.
R5976766 RLM G5 22/04/2004
51