Transistor & Diode Circuit - ViewSonic P774B-2NT Series Service Manual

The X-ray protection input pin25 provides a voltage detector with a precise threshold. If the voltage
exceeds this threshold for a certain time, an internal latch switches the whole IC into protection mode.
In this mode several pins are forced into defined states:
Vertical Oscillator
The vertical free –running frequency is determined by the resistor C610 at pin19. Usually the free-
running frequency should be lower than the minimum trigger frequency.
5-3 TRANSISTOR & DIODE CIRCUIT
LOCATION
D901 ~ D904
D910
D918, D919
D922
D923
D925
Q901
Q907, Q908
Q909, Q918
Q912, Q920
Q913
Q921
Q701
Q402
Q426
Q404, Q405
Q406
Q705
CIRCUIT FUNCTION DESCRIPTION
Bridge Rectifier for AC Source
Clamp Diode for Snubber CKT
Rectifier for Output Voltage
Rectifier for Output Voltage
Rectifier for Output Voltage
Rectifier for B+ Supply
MOS FET for Switching Power Control.
Use for Off-Mode to Cut-off 6.3V Supply Voltage
Use for Standy-By or Suspend Mode to Cut-off 12V Supply Voltage
Push-Pull Topology to Drive Q911
Degaussing Switcher Transistor
5V Regulator Transistor
Turn-on at Power ON/OFF and Change Mode to Protect Hor.Block
HOR. Driver Transistor
Horizontal s correction control MOSFET
As Differential Amp. to Drive Q406
Transistor for H-Size Control
Brightness Control CKT
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