Dell E1709W Service Manual download pdf (Page 7)

Service Manual

Electronic Circuit Theory

2.1 Inverter PWM circuit

2.1.1) Inverter Control circuit :( fig.2)

R18 0R

R10

200k/Open

OLP1

C35A

R15

10K

ZD3

BAV70

10R

330k

10nF

ON/OFF3

ISEN1

C14

10nF/25V X7R

100K

C11/Open

0.1uF/25V

+5V

ZD5/Open BAW56

DIM3

R16

100K

820K

T1A

10K

P6006HVG

R22

30K/Open

R13

R17 10K/Open

R30

33R

10nF/25V X7R

C13

10nF/25V

R28

5K/Open

2.2uF/16V

100K

47K

OLP2

R3 10K

+5V

T1B

+12V

C10

2.2uF/10V

C27

120p/Open

C36A

INL837

8 9

DRV1

VDDA

DIM

ISEN

PID

RSTR

ENA VSEN

OVPT

LCT

SSTCMP

TIMER

GNDA

DRV2

47nF/16V

D9/Open

1N4148

C26

2700p

R29

33R

R11

3.3M

270pF/16V NPO

C34A

PID_Input

R12

91K 1%

R20

100K

R14

C16

27nF/Open

R26 0R

C25

2700p

C33A

2.2uF/10V

C23

1nF/50V

R24

4.7K

C28

120p/Open

C22

1nF/50V

33nF

100K

ZD4/Open

BAV70

R21

100K

R23

30K/Open

C24

0.1uF/50V

1nF

D10

1N4148

DIM

ISEN2

C18

27nF/Open

Fig.2

DC_5V through R1 and C1 will provide power for U1 on the pin2 (VDDA).

EN-ON/OFF voltage signal coming from scalar which is on IF BD will enable U1 to work. This

applies a level greater than approximately 2V to pin8 (ENA) enables the IC, A voltage less than 1V

will disable the IC. R3 is used to limit current.C3 and R16 is used to dump noise.

The soft-start function is provided by connecting C8 to pin12(SSTCMP), In the start-up mode,

current charges C8, its voltage controls the gradual increase in power to the transformer and

subsequently to the output load, this reduces in-rush current and provides reliable operation to the

CCFL.If no current is sensed approximately 2 seconds, U1 shuts off. Once the voltage at the pin4

(ISEN) reaches the lamp on threshold, the IC switches from the striking mode to the normal

operation mode and the PWM dimming control is activated.

DIM-ADJ duty cycle signal through R2 and C2 is on Pin 3(DIM), which adjusted will can

change the brightness of Panel. R15 is used to limit current. Internal LPWM dimming control is

determined by R11 and C7 connected to LCT (pin11), analog dimming is implemented by providing

1 2 3 4 5 6 7 8 9 10 11 12 ... 61 62

Comments to this Manuals

No comments

Dell E1709W Service Manual Page 7

Comments to this Manuals

Related products and manuals for TVs & monitors Dell E1709W