BLACK LEVEL STABILITY CIRCUIT IN CRT

摘要

The device prevents the irregularity of the display and achieves accurate contrast signal by automatically controlling the black level of the CRT according to the video level. The device comprises: an adder which sums video signal of the color matrix with level signal of the measured pulse; a limiter which restricts the amplitude of the adder output; a mixer which mixes the limiter output, the external white level adjust signal, and feedback signal; an amplifier which amplifies the mixer output; transistor and resistor which bypasses the cathode current to ground.