| 摘要 |
PURPOSE:To increase the controlling range of a chopper by connecting the chopper between a DC power source and a load and continuously varying the chopping frequency in relation to the current flow rate of the chopper. CONSTITUTION:A motor 10 and an armature current detecting resistor 16 are connected through a chopper 12 to a DC power source 14. A motor current instruction voltage from a current setter 22 and detecting voltage of the resistor 16 are inputted differentially to an amplifier 20, the output of the amplifier is inputted through a limiter 24 to one terminal of a comparator 28, and the output of the limiter 24 is inputted through a frequency regulator 30 and a triangular wave generator 32 to the other terminal of the comparator 28, and the chopper 12 can be controlled ON or OFF by the output signal. Accordingly, the chopping frequency of the chopper 12 can be interlocked with the current flow rate, thereby performong the improvement in the controllability in a low speed range, the expansion of the controlling range and the reduction in the noise of a motor. |
