| 摘要 |
PROBLEM TO BE SOLVED: To compensate for a torque at a low-speed region by performing the positive feedback of the detection voltage of a drive signal current to the sum synthesis circuit for setting speed and performing control to increase a signal current. SOLUTION: An output value 1a of a sum synthesis circuit 1 for inputting speed setting 2 as a voltage value is inputted to a pulse width modulation PWM generation part 3, and output 3a is applied to a power element 5 via a logic element 4 for composing a switching circuit and a comparison circuit. A drive signal 5a is supplied to a motor 7 for driving via a current detection part 6. A voltage value 6a for indicating a current value obtained from the current detection part 6 is inputted to the logic element 4 via a current limit detection part 8 and is subjected to positive feedback to the sum synthesis circuit 1. When the motor 7 is subjected to negative feedback, a motor load increases. When the motor load goes below a setting speed, a back electromotive voltage decreases and a current increases. At the same time, a voltage value 6a due to the detection of the current is inputted to the sum synthesis circuit 1 and the output value 1a is inputted to a PWM generation part 3 as the voltage sum with the speed setting 2. The output 3a from the PWM generation part 3 increases, thus improving a torque. |
