Picture tube beam current suppression circuit - applies constant voltage to blanking circuit making it operative when beam blanking pulses fail

摘要

The picture tube beam current is suppressed when parts of the equipment surrounding the tube fail. The circuit has a circuit controlled by blanking pulses which blanks the electron beams during a period of the electron beam cycle not used for display. Blanking pulses are so coupled with a constant voltage (Usp). that when the blanking pulses fail, the voltage (Usp) is applied to the blanking circuit (11) input and makes it operative. The pulses are fed to the blanking circuit over a clamping circuit including a diode, capacitor, and two resistors, which is connected to the voltage source.