Abstract: Switching the time constant of a filter in the APC-loop of a color television receiver is done by a keyed transistor switch so that the circuit is suitable to be formed as an integrated circuit.

Abstract: A circuit arrangement in a picture display apparatus including an integrator having a time constant which is of the same order as one field period and which integrates the control voltage generated by the line phase discriminator. The voltage thus integrated is applied by means of a switch to the output terminal of the discriminator during each field blanking period. As a result both the flickering effect and the shift which may occur at the upper edge of the screen of the picture display tube as a result of the broad field synchronizing pulses and the equalizing pulses disappear. The circuit arrangement also includes a circuit which separates the discriminator from the integrator and which may be constituted as a long-tailed pair arrangement.