Abstract: An arrangement for a television receiver is disclosed which facilitates the coupling of synchronization signals to an on-screen display integrated circuit of the receiver. The receiver includes sources of periodic vertical and horizontal rate pulses. A composite timing signal generator combines the vertical and horizontal rate pulses so as to form a composite timing signal in which the horizontal rate pulses are absent during the duration of each vertical rate pulse. The composite timing signal is coupled via a single conductor path to an input terminal of the on-screen display circuit. The composite timing signal can be readily decoded by a simple digital counter to provide separate horizontal and vertical rate pulses for the on-screen display circuit.
Abstract: In a video display monitor having a multiple rate scanning capability, a synchronized switching power supply develops the regulated operating voltages for the monitor. A deflection circuit produces scanning current in a deflection winding and is capable of being operated at either one of two selectable scanning frequencies. A signal synchronously related to the scanning current, such as a retrace pulse voltage, is applied to the control circuit of the switching power supply. The control circuit generates a control signal from the retrace pulse voltage that is synchronously related to the scanning current and of a frequency that is unchanged when the deflection circuit is operated at either of the two selectable scanning frequencies. The output stage of the switching power supply responds to the control signal and produces switching operation at the unchanged frequency in synchronism with the scanning current.