Helical scan recorder having capstan motor speed responsive to a frequency of a command signal

Claim 1

A motor speed control circuit for a motor of a video tape machine operable to move the tape at normal or at search mode speeds comprising, a rotational speed generator associated with said motor and producing a series of pulses which have a pulse repetition rate indicative of the motors speed, a motor drive circuit supplying a signal to said motor, a first saw tooth wave generator receiving the output of said rotational speed generator, a first integrating circuit receiving the output of said first saw tooth generator, a phase lock loop generator, a second saw tooth generator receiving either the output of said phase lock loop or a variable frequency search command signal, a second integrating circuit receiving the output of said second saw tooth wave generator, a first comparison circuit receiving the outputs of said first and second integrating circuits on its negative and positive input terminals respectively, and supplying an input to said motor drive circuit, and the time constant of said first integrating circuit being larger than the time constant of said second integrating circuit.