| 摘要 |
<p>A brake pulse generating circuit determines the direction of rotation of a capstan motor at the edges of signals FG1 and FG2 by using D-type flip-flops (21, 22, 23 and (24) and a NOR gate (25). A brake pulse f having a longer pulse width supplied from an intermittent drive circuit (10) for counter-current braking of the capstan motor, is terminated by an AND gate (27) as soon as it is detected that the capstan motor is inversely rotated. The brake pulse is then applied to a capstan motor drive circuit as a corrected brake pulse having a proper pulse width. A motor drive signal g supplied from the intermittent drive circuit (10) is also terminated by an OR gate (26) as soon as it is detected that the capstan motor is inversely rotated. However, an EX-OR gate (28) helps prevent the termination of the motor drive signal g that will be caused when the direction of rotation is erroneously determined at the time when the capstan motor is started.</p> |
