| 摘要 |
PROBLEM TO BE SOLVED: To increase the speed gain of the constant speed control of an SR motor, while avoiding hunting generated in a light load state. SOLUTION: A detection signal (error value) of a 2nd operational amplifier 6, to which a speed command signal and a speed detection signal are inputted, is full-wave rectified by a full-wave rectifying circuit 5. The full-wave rectified error value is inputted to the non-inverted input terminal of the 1st operational amplifier 2, and at the same time, to the base terminal of an NPN transistor 1, whose collector terminal is connected to the reverse input terminal of the operational amplifier 2. Furthermore, the emitter terminal of the NPN transistor 1 is grounded via a resistor R1 and the collector terminal of the NPN transistor 1 is connected to the output terminal of the 1st operational amplifier 2 via a resistor R2, to obtain the gain of the 1st operational amplifier, which is 1+(R1+R2)/R1. |
