Pcb-Deflection Circu~T - Mitsubishi C-6919 Service Manual

capacitors C610 and R610 and applied to the base of
transistor Q603. The differential amplifier, formed
by transistors Q603 and Q604 compares the voltage
across R308 with the reference level set by potentio-
meter VR601. If the voltage drop across R308, produced
by the beam current, exceeds the level set at VR601,
transistor Q603 conducts and turns on transistor Q605.
The collector of transistor Q605 pulls the CRT grid
voltage negative to limit the beam current.
3.5 PCB-DEFLECTION CIRCUIT
This PCB unit contains Vertical Deflection circuit,
Horizontal Deflection circuit, High Voltage circuit, PCC
circuit and High Voltage Protector circuit.
3.5.1 Vertical Deflection Circuit
The vertical deflection circuits consist of the IC503,
(contains the vertical oscillator and vertical driver),
vertical output stage and vertical centering circuit.
~ H-OSC
IC503 HAll414
Fig. 3-1 Block Diagram of IC503
The vertical sync pulse is applied to pin #8 of IC503,
and oscillator sawtooth wave generated in the IC503 is
compared with the feed back deflection current wave
developed across R40B and R409. Height control, VR402
adjusts the waveform of the feed back voltage.
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