Circuit for producing a dynamic focusing voltage in a television set

摘要

A circuit for generating a dynamic focusing voltage in a television receiver utilizing overscan periods includes a focusing voltage generator. The focusing voltage is compared to a reference voltage and a switching signal is provided when the focusing voltage goes below the reference voltage. A switch is responsive to the switching signal and provides a direct focusing voltage during the overscan periods. The direct focusing voltage has a level which maintains the arithmetic mean of the focusing voltage the same during the normal scan period and the overscan periods.