| 摘要 |
PURPOSE:To increase output torque according to the increment of load torque and recover from stalling quickly, by setting the output voltage and output frequency of an inverter with excess current signal. CONSTITUTION:From a micro-computer 38, the frequency of a frequency setting section 41 and the voltage of a voltage setting section 42 are fed to a PWM (pulse width modulation)generating section 40. The output of the PWM generating section 40 is fed to a base amplifier 36 via a buffer 37. By the base amplifier 36, a power transistor 35 is driven. In this case, when the load of a compressor 34 gets greater, then frequency is lowered by the excess current signal of an excess current detector 39 through the micro-computer 38, in order to protect the power transistor 35. As a result, generation torque is increased. Then, by lowering the frequency, a pattern refrigerant flow rate is reduced, and a compressor load is also reduced, and so. a device is quickly recovered from a stalling state. |
