Transistorized Vertical Scan System for Magnetic Deflection

Abstract

A transistorized vertical deflection system has been developed to scan a 90-degree, 14-inch picture tube at 14 KV accelerating voltage. This system consists of two transistors in a common-emitter multivibrator to form a vertical oscillator, one transistor as a driver and one output transistor, and the system is supplied power from a 12-volt d-c source. To prevent decentering of the raster, due to the d-c component of current in the deflection-coils, the output stage is coupled to these coils by means of an isolation transformer. Feedback networks are introduced to correct for the non-linear characteristics of the transistors, and to predistort the input waveform to the output transistor in order to compensate for the non-linearity of the transformer.