Circuit Operation Theory - BenQ G2010WP Service Manual

Inverter board
2,4 +16V
FB802 85Ω
2 VCC5V
R517
33
R522
200K
R512
10K
2 BRIGHTNESS
C510
1000p/50V
R542
200K
2 ON/OFF
R501
10K
R518
470K 1%

5.5 Circuit Operation Theory

5.5.1. Electronic Circuit Theory
Low voltage to high voltage circuit
16VDC provides the power for IC501; the control signals Brightness and ON/OFF come from I/F board. ON/OFF
signal connect to R501 to control pin1 of IC501 and makes IC501 enable. Brightness signal connect to pin3 of IC501
and regulates the panel brightness, delaying time circuit is setting by the IC501 internal , C510 is used to dump noise.
The operation frequency is determined by the external Resistor R508 and Capacitor C512,C521 connected to pin13
of IC501. BURST MODE regulated dimming frequency is determined by the external resistor R516 and capacitor
C516 connected to pin11
noise.
The output drives, include DRV1, DRV2 (pins1,16 respectively) output square pulses to drive MOSFET U501, U502,
and each of U501, U502 , is consist of dual N channel MOSFET. U501,OR U502 work as Push-Pull- topology, it is
high efficient, PWM switching.
During start up, R519 senses the voltage at the transformer secondary. When OVP reaches Vense 3v Level, the output
voltage is regulated. If no current is sensed approximately 2seconds IC501 shut off.
C503
NC
R534
15
C507
2.2u/16V
1 16
DRV1 DRV2
2 15
VDDA GNDA
3 14
DIM TIMER
4 13
ISEN CT
5 12
PID SSTCMP
6 11
RSTR LCT
7 10
RT OVPT
8 9
ENA VSEN
R513 R515 IC501
75K 1% 1M 1% INL837
C520
0.1/50V
C518
0.01/50V R537
10K 1%
R539
5K1 1% 1 IS1
3 D506
IS2
2 BAT54
R538
C517 10K 1%
6800p/50V
of IC501. C511 is used for soft start and compensation, C518, C519 are used for dump
R504
C501
33
C502 470u/25V
NC
C504
1000p/50V
1 8
2 7
3 6
5V 4 5
U501
AP9971GD
R507
3M3 1%
R508
43K 1%
R535
15 R532
33
C515 C529
2.2u/16V 1000p/50V
1 8
2 7
3 6
4 5
U502
AP9971GD
R520
100K 1%
D505 D511
SN4148 SN4148
R526
1M
D512
SN4148
R519
C519
1M
0.1/50V
32
R505
33
R506
1M5 3KV
C505
1000p/50V
1 7
R540
3 C506 20K 1%
10p/3KV
C508 4 R510
NC 1K8 1%
6 8
T501
SPW-080
C509 2
3p/3KV 3
1
C513 C514
470p/50V 3900p/50V
R530
33
R525
C522 1M5 3KV
1000p/50V D508 BAV99
1 7 3
3
R541
C526 4 C523 20K 1%
NC 10p/3KV
6 8 R531
1K8 1%
T502
SPW-080
C531
5V 470u/25V C528 2
3p/3KV 3
1
D509
op1 BAV99
C525 C527
op2
470p/50V 3900p/50V
InnoLux BenQ G2010W
Document Number : SIZE :
TITLE :
Inverter
2008-01-08
DATE :
Rev :
3 3
SHEET OF
1
H
CN501
op1
2 4100-D02
L
R524
200
3
D502
BAV99
1 2
1
H
R521 CN502
470 2 4100-D02
L
1
D503 3
BAV99 D504 2
BAV99
IS1
C530 R536
2200p/50V R523 6K8 1%
820 1%
1
H
CN503
op2
2 4100-D02
L
2 R527
200
1
1
H
R529 CN504
470 2 4100-D02
L
1
3
D507 2
BAV99
IS2
C524
R533
2200p/50V R528 6K8 1%
820 1%
APPRO BY :
Custom
CHECK BY :
DRAWN BY :
V01