Dell E1709W - Power PWM Circuit; AC Input and EMI Filter

Service Manual
8
2.2 Power PWM circuit
2.2.1) Block diagram :( fig.4)
Fig.4
2.2.2) AC Input and EMI Filter :( fig.5)
fig.5
CN850 is a connector for connecting AC Power. F850 is a fuse to protect all the circuit AC.
Input voltage is from 90V to 264V. R850 and R851 are joined between two inputting main circuit
to prevent man from shock. L850 is used to clear up low frequency wave. C850 and C851 are
RT850
5R4A
VZ850
10561 NC
F850
3.15A 250V
C851
332 Y 2
C850
332 Y 2
R850
750K
C852
0.47uF X2
CN850
HF-301PCB 7MM
1 3
2
L850
CHK-007
4
3
1
2
R851
750K
EMI Filter
Rectifier and
filter
Isolation power
transformer
Rectifier and filter
Inverter circuit
PWM controller
Switching element
Feedback Isolation
Rectifier and filter
LDO regulator