| 摘要 |
PURPOSE:To optimally set a torque, to operate in a low frequency range, to further reduce an input, and to improve feeling at the time of operation by varying an input voltage in response to a load at the time of low frequency operation. CONSTITUTION:A DC current detector 11 detects a load current of a compressor 16, and inputs it to a LSI 13. The LSI 13 contains a comparator, a discriminator, a calculator, and a memory for storing compressor rotating speed controllers I, II (frequency/voltage characteristics I, II). The LSI 13 compares a DC current value with a set DC current value to discriminates it, and drives a power transistor 14. Thus, the input voltage of the compressor 16 is varied corresponding to the load of the compressor 16 and hence a DC current value to optimally set a torque. |
