8.1 Circuit Diagram of High Voltage Hold Down Circuit.
The high voltage hold-down circuit protects the high voltage circuit from dangerous voltage with short circuiting between emitter and collector of power-regulating transistor.
The base voltage of X701 is increased when the B1 voltage is increased more than 138.5 V DC.
When the base of X701 is increased, a short is produced by X701 between pin 11 and ground of IC 501, shutting down the horizontal osc. and high voltage.
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