| 摘要 |
<p>PURPOSE:To preferably brake via DC a motor by detecting the current flowed to the motor, and limiting the current so as not to exceed the prescribed value when the current reaches the prescribed value lower than the current for operating an inverter protecting unit. CONSTITUTION:When the output voltage of an operational amplifier 2 becomes negative, the output of an operational amplifier 4 is inverted, an integrating capacitor C3 is charged, and the output voltage of the amplifier 4 is raised. A negative voltage is outputted from a NOT element at the time when it becomes slightly positive voltage over zero voltage, a signal of a chopper controller CS outputted from an AND element A is stopped, a transistor Tr is interrupted, and a current is stopped by an inverter I. Accordingly, a motor M which is rotating at a low speed is stopped by a DC current limited for the prescribed time.</p> |
