| 摘要 |
PURPOSE:To limit a current flowed to a motor irrespective of the gain of an amplifer by turning OFF a PWM signal when a detected current value exceeds a current limit value. CONSTITUTION:A PWM signal generator 4 generates a PWM signals for driving a servo motor so that the position of the shaft of a motor, the difference between the speed and the command value becomes zero. When the current value detected by a current detector 2 exceeds the current limit vlaue of a servo motor 1, the output of a comparator 31 becomes high level. At this time, the generator 4 outputs PWM ON signal. Accordingly, the input of a flip-flop 51 becomes low level. Therefore, when the output of the comparator 31 becomes high level, the Q output of the flip-flop 51 becomes low level, and the output signal of a PWM signal generator is set by AND gate 52, 53 to low level. |
