THYRISTOR TRIGGER CIRCUIT

PURPOSE:To prevent appearance of lateral lines on a screen by connecting a signal terminal between an anode and a gate of a thyristor and turning on the thyristor via a cathode. CONSTITUTION:A sawtooth wave current I1 flowing from a vertical deflection output circuit 1 flows to a path of a vertical deflection york V-DY, a resonance circuit 3 and a resistor R2 and energy is stored in a capacitor C2. Then a switch SW is closed for a horizontal blanking period 4 and a charge in the capacitor C2 is discharged through a coil L2. Even after a voltage across the capacitor C2 is zero by the resonance of the coil L2 and the capacitor C2, although the current of the circuit 3 is going to flow, the circuit constant is set so as to open the switch SW by a control signal. Furthermore, the switch SW is opened for a horizontal scanning period 6, and a resonated parabolic current I2 flows to the yoke V-DY-a damping circuit 2. The circuit 2 bypasses the current I2 from the circuit 1 and no lateral line is caused on the screen.