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Explanation for circuit operation
2-1) Horizontal B+ supply part
This horizontal B+ supply part cuts off horizontal B+ power by two TRs, using a Darlington
circuit. DC voltage supplied for E/W terminal (Pin No. 11) in deflection IC(I403) is input to EW
1st inversion circuit IF11 PIN2 by using EW waveform and then output to PIN1. The amplified
EW waveform is output to PIN7 and connected with B+ drive circuit, which is supplied for the
Darlington circuit composed of Q403 and Q404 through Q311 connector and C417, R429
horizontal. 135V via D415 and R433 is supplied for Q403, Q404 connector. When 100V is
supplied for Q403 base, DC voltage (100V-110V) amplified in Q404 and E/V compensating
waveform supply B+ for horizontal output Tr (Q402) by R409 and D405 via pin drive trans
T402 and dummy trans T403.
2-2) Horizontal output part
The horizontal output part makes a voltage and current enough for horizontal deflection
using a power supplied from horizontal B+ generator and drives H drive trans (T401) after
application to Q401. The drive pulse via H drive trans is supplied for the base of horizontal
output Tr (Q402) base and operates the horizontal output Tr. When it works. a horizontal
output voltage is made by using a horizontal deflection coil and retrace condenser (C407,
C408). At this time, the horizontal output voltage is approx. 1000V to 1200V and the retrace
time is approx. 4.0 sec. The horizontal output current via the deflection coil is supplied for CS
condenser (C409, C410).
3) Vertical drive part
The vertical drive part consists of +12V, -12V positive power, using TDA8172, vertical output
IC of SGS-THOMSON Co. Ltd. and performs vertical deflection and vertical-related
geometrical correction. The main operations of this vertical drive part are as follows. The
vertical waveform and vertical correction signal outputted to the vertical output terminal
(PIN12, PIN13) of vertical/horizontal deflection IC (I403) are input to inverted input terminal
(I412) of vertical output IC (I412), amplified in the vertical output I, outputted to the output
terminal (PIN6) and applied to vertical deflection coil. For the current via the deflection coil,
DC-feedback via R311 and AC feedback via C318 are executed.
4) High voltage generating part
The high voltage generating circuit uses a high voltage generator for projection, differently
from the conventional FBT method. This HVG has been developed by PHILIPS CO., LTD.
and performs the following operations. The HVG module is composed of 10 pins, 3 EHT
output holes and 1 focus output hole. Each terminal is displayed below.
PIN 1 : NC
PIN 2 : ABL ( BEAM CURRENT INFORMATION )
PIN 3 : GROUND (AUXILIARY VOLTAGE )
PIN 4 : AUXILIARY VOLTAGE ( -220V )
PIN 5 : NC
PIN 6 : NC
PIN 7 : OVP ( TEST POINT FOR OVER VOLTAGE PROTECTION )
PIN 8 : ON/OFF (ON/OFF 5V)
PIN 9 : GROUND
PIN10 : VB+ ( POWER SUPPLY VOLTAGE )
