Reference frequency generator for film transport velocity control

摘要

A reference frequency generator for the control of a film transport velocity comprises a first counter, dividing a supplied studio reference clock by a presettable factor. There is a digitally controlled oscillator, whose output clock, or a clock derived from it by division, is used for the control of the film transport velocity. A phase comparison stage compares the divided studio reference clock with the output clock pulse of the digitally controlled oscillator, with the result fed to the oscillator as the control signal.