| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a power supply unit avoiding influence of fluctuations in electric voltage of electric power of power supply. SOLUTION: Electric voltage for electric power of power supply, which is input to an input terminal 1, is detected by a detector 14 for electric voltage of power supply. A signal level Vs of this detected signal is compared with respective standard signal levels Va and Vb, Vc and Vd in each electric voltage comparator 15 and 22, respectively. Consequently, electric voltage of power supply is determined whether or not it is within an allowable rated range and it is also within a maximum allowable range. Namely, when electric voltage of power supply is out of the above-described allowable rated range caused by fluctuations of electric voltage of power supply, the electric voltage comparator 22 outputs a signal for showing a change of electric voltage of power supply. On the basis of the signal of the electric voltage comparator, a warning indicator 26 is lit. Further, when electric voltage of power supply is out of the above-described maximum allowable range caused by large fluctuations of electric voltage of power supply, the electric voltage comparator 15 provides an abnormal signal for electric voltage of power supply to an inverter stopping portion 18 in order to stop drive control of an inverter circuit 4 in an inverter control portion 5.</p> |
