Abstract: A multisync horizontal drive generator for use in a television receiver or computer monitor display is operative in response to an applied horizontal scan synchronizing signal. A delay network couples the horizontal sync signal to a gated detector which compares the delayed horizontal sync signal to a differentiated horizontal scan flyback signal to produce an error signal. A gain adjustable error amplifier couples the error signal to a summing network which includes a nominal frequency input. A range control detects the frequency of the horizontal drive signal and applies a range control signal to the summing network. The combined signal inputs are coupled from the summing network to a signal controllable current source which drives a saw forming network to produce a horizontal scan signal.

Abstract: A television receiver includes conventional systems for receiving a broadcast type signal and displaying the received signal upon a cathode ray tube. Vertical and horizontal scan system oscillators and controls produce vertical and horizontal scan signal synchronized to the reference sync signals. A scan clock system cooperates with the horizontal oscillator and control system to produce horizontal scan related signals which are synchronized to the CRT scan.

Abstract: A multiple frequency scan oscillator control system includes a phase locked loop operative upon a scan oscillator to provide phase and frequency synchronization thereof to a periodic reference signal. A static phase error correction is operative to provide adjustment of the free-running or static frequency of the scan oscillator. An error amplifier includes a pair of intercoupled differential amplifier configurations one having a constant current source and the other having a frequency dependent current source which responds to a frequency dependent bias current to alter amplifier gain. A threshold detection circuit includes a differential amplifier pair coupled to a pair of switching circuits for establishing a threshold action in response to system error voltage to indicate large magnitude error voltages and signal the need for free-running frequency adjustment of the oscillator.