| 摘要 |
PURPOSE:To achieve smooth rotation, by comparing the output from a drive speed detecting means with an external drive speed control voltage and varying the output voltage, thereby varying the width of an output pulse and increasing the amplification factor under low speed driving. CONSTITUTION:A drive speed controller for a vibration wave motor applies an encoded output of motor rotation to a drive speed detecting means 1. The means 1 comprises a mono-stable muiti-vibrator 11, a filter 12 for DC voltage conversion and an operational amplifier 13. Output voltage from the means 1 is fed to a differential amplifier 2 for detecting the difference between the output voltage and an external drive speed control voltage and to a low speed operation circuit 3. The operational amplifier 2 is connected to an operation amplifier 14 and the like, while the low speed operation circuit 3 comprises an operational amplifier 15 and the like. The gain of the differential amplifier 2 is increased during super low speed driving immediately before stoppage thus realizing smooth rotation. |
