Switching arrangement for convergence faults - designed for correction of corner convergence in three electron beam CRT

摘要

The switching arrangement is based on a circuit having a line frequency convergence potential capable of being modulated in both directions by a picture frequency potential. The latter is derived from the collector of a transistor connected on the input side between the base and emitter electrodes. The base electrode can be fed to the second forward trace sweep potentials. Between the base and emitter electrodes two potentiometers are switched in parallel with a tapped earth connection. The layers of the potentiometers are connected, via diodes, to a source of single phase vertical frequency saw-tooth potential. The diodes are so terminated that in the pair of potentiometers a loop comprises the first forward trace half and the other logs the second forward trace half of the saw-tooth potential.