| 摘要 |
PROBLEM TO BE SOLVED: To provide an insulation resistance measuring apparatus capable of simply and always continuously measuring insulation resistance between AC electrical paths of a hot line (electrification) condition.SOLUTION: The insulation resistance measuring apparatus includes: a full-wave rectifier circuit for rectifying a voltage between AC electrical paths; first and second voltage-dividing resistance circuits connected in series and interposed between output terminals of the full-wave rectifier circuit to divide an output voltage from the full-wave rectifier circuit and respectively find out a positive pole side reference voltage and a negative pole side reference voltage; a detection resistor interposed between a series node of the voltage dividing resistance circuits and a grounding point; a reference voltage signal generation circuit for obtaining a reference voltage signal by respectively rectifying the positive pole side reference voltage and the negative pole side reference voltage obtained through an insulation converter; a detection voltage generation circuit for obtaining a detection voltage signal by rectifying the detection voltage obtained through the insulation converter; and an arithmetic circuit for finding out insulation resistance by dividing the reference voltage signal by the detection voltage signal, and then multiplying the divided value by a predetermined coefficient. |
