| 摘要 |
PURPOSE: An apparatus for diagnosis of a secondary resistor of a wound type induction motor is provided to prevent damage of product by detecting and displaying faults of the secondary resistor. CONSTITUTION: An apparatus comprises a current detection unit(10) for detecting current flowing at a secondary resistor of a wound type induction motor(2); an amplifier unit(20) for amplifying the detected current; a current comparing unit(40) for comparing the detected voltage corresponding to the detected current, with a preset voltage, and outputting a level signal in accordance with the result of the comparison; a fault detection unit(50) for detecting faults in accordance with the level signal output from the current comparing unit, and outputting pulses upon detection of faults; a fault determination unit(60) for counting pulses of the fault detection unit, comparing the counted pulse with a preset pulse, and outputting a level signal; a switching control unit(70) for outputting on/off switching signals in accordance with the level signal output from the fault determination unit; and a power switch(1) arranged at a power supply terminal of the induction motor, and which switches power supply in accordance with the switching signal output from the switching control unit.
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