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36
CIRCUIT DESCRIPTION
TURNING ON THE DEFLECTION POWER SUPPLY: See Figure 5
When the Projection Television is turned on, the Microprocessor outputs a high for Pin (35), which is
inverted by Q002. This low is routed through the connector PQS1 pin (8) on the signal PWB to the Sub
Power Supply PWB. It is then routed to Q903, and its collector will go high. This will pull up pin (5) of
I907 and I908, turning ON the two DC to DC converters. The output of both DC to DC converters I907
and I908, are used by the relay which supplies AC voltage to the Deflection Power Supply on the Power/
Deflection PWB. The output of I907 SW+5V regulator supplies B+ for pin (3) of the relay S901. The
output of I908 SW+12V drives the base of Q911 turning it on and grounding pin (4) of the relay S901. The
relay now provides AC to the bridge rectifier on the Deflection Power Supply.
QP04
I001
Micro
Processor
Power On/Off
53
Q002
PQS1
8
Stby +11V
I701
8
DVcc
Power ON
Driver
(Relay Driver)
SIGNAL PWB
SUB POWER PWB
DEFLECTION PWB
SUB DEFLECTION PWB
ZP-94/95 DEFLECTION Vcc PRODUCTION CIRCUIT
Other Power
On/Off Circuits
From I906 Stby +11V Reg.
PQD2
3
1
STBY +11V
Start Up Power
DP21
Power On by
Remote Control or
Front Power Key Press
DP35
DP36
Q003
Q004
Turns on I009 SW +9V Reg and
IS13 +5V Reg on Surround PWB
B+ GENERATION FOR THE DEFLECTION POWER SUPPLY DRIVER IC See Figure 1
Vcc for the Driver IC is first generated by the AC input. This voltage is called Start-Up Voltage. IP01
requires 21V DC to operate normal. However, it will begin operation at 14.5V DC on pin (4) of IP01.
When AC is applied by the relay on the Sub Power Supply R901, AC is routed through the connector
PQD1. Then it arrives at the bridge rectifier DP01 where it is converted to DC voltage. One leg of the AC
is routed to a half wave rectifier DP02 where it is rectified, routed through RP02 and RP03 (both a 5.6K
ohm resistor), filtered by CP05, and made available to pin (4) of IP01 as start up voltage. The Red LED
DP37 is illuminated by this power supply. When this voltage reaches 14.4Vdc, the internal Regulator of
IP01 is turned on and begins the operation of IP01.