| 摘要 |
PURPOSE:To phase-control the speed feedback without responding delay by always maintaining the charging time per one pulse constant by a charging time fixing circuit. CONSTITUTION:A speed signal S6 detected by a tachometer generator is set to a rectangular wave signal S7 by a comparator 13, and input through a light emitting diode 14, a phototransistor 15 and an inverter 17 to a charging time fixing circuit 18. The signal always becomes a charging time stationary pulse signal S8 that one pulse is generated only for the prescribed time in the circuit 18. Charging and discharging operations are repeated in the next charging/discharging circuit 22 to become a smooth sawtooth wave signal S9. The signal S9 is compared by the reference sawtooth wave voltage obtained from a reference sawtooth wave forming circuit 25 to regulate the motor applying voltage so that the motor rotates constantly at the preset speed. |
