Service manual

CB-24
CB CIRCUIT DESCRIPTIONS
High Voltage Shutdown
The x-ray protection (high voltage shutdown) circuit uses the current from pin 6. DX3002 and CX3003
convert this current to DC. The resulting voltage is applied to the resistor divider network in the emitter
circuit of QX3002. Voltage applied to the base of this transistor remains constant because of the zener
diode, ZDX3004. If HV reaches 35.7 kV (33.9 kV for 27 sets) DC applied to the emitter of QX3002
will switch the transistor on. The resulting voltage across RX3002M will switch QX3001 on, attenuating
the flyback signal on pin 18 of the video processor. If the signal is reduced to 1 Vp-p or less, IC2200 will
cease production of H-drive and thereby shut down the set.
<<Figure CB-22>>
Vertical Amplification
The yoke receives vertical sweep drive from ICX2100, the vertical amplifier. This IC consists of a pump-
up stage, a power amplifier, and thermal protection circuitry. The ±14VSW power the IC at pins 1 and 6.
DX3002
CX3002
CX3003
RX3005
RX3006
ZDX3004
RX3003
RX3004
RX3002M
DX3001
RX3001M
RX3211
QX3002
RX3007
CX3001M
QX3001
D2205
R2224M
R2222M
R2223M
PROV
C2241M
C2214M
PROV
C2215M
PROV
From Sweep
Transformer
Flyback
Pulse
To Shutdown
Pin 18, IC2200
7
1
2
3
4
5
6
221-1410
ICX2100
-
+
AMP
Pump-Up
Thermal
Protection
<<Figure CB-23>>