摘要 |
Apparatus and method for controlling the speed of a tape drive having an ingoing capstan and an outgoing capstan with a magnetic head therebetween. First and second phase lock loop servo-circuits for driving first and second dc motors which drive the ingoing and outgoing capstans, respectively. A stable reference oscillator providing the reference frequency to one of the phase lock loop servo-circuits and to another phase lock loop circuit which provides the reference frequency to the other phase lock loop servo-circuit. The feedback frequency in the third phase lock loop circuit is adjustable to control the difference in the two reference frequencies to the two servo-circuits for the purpose of controlling the difference in speeds of the ingoing and outgoing capstans.
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