Control device for tape transport speed - has phase of vertical synchronisation pulses from track compared with reference signal and used for speed control

摘要

The tape transport speed control device also ensures accurate track holding during reproduction of video signals recorded in oblique tracks on a magnetic tape. A full frame or a field is recorded in each track. Phases of vertical synchronisation pulses scanned from the oblique tracks and separated are compared with a reference signal. An error signal so obtained read-justs the transport mechanism motor through its servo control. The sequence of components consists of an amplifier (5), an FM demodulator (6), a synchronisation signal separator (7), an integrator (8), a manually operated phase adjusted (14), a phase comparator (9), a voltage controled oscillator (12) and a servo-mechanism (13). The phase comparator (9) also receives signals from the impulse former (11).