| 摘要 |
PURPOSE:To reduce power due to index generation to the utmost by applying power to an index generating circuit via a changeover switch when a signal indicating the number of revolutions of a motor transmitted from the host side shows a prescribed value. CONSTITUTION:When a motor-on signal from a host computer 1 is logical 1, a motor drive circuit 11 drives a DC motor 4 to drive a floppy disc 3. A switching circuit 10 supplies +5V to alight emitting element drive circuit 9 at the same time to light the element 6. Every time an index hole H crosses a line typing the element 6 and a photodetector 5, a pulse is outputted via an amplifier 7 and a waveform shaping circuit 8.
|
