| 摘要 |
A leakage detection circuit of the present invention includes a branch having a body ground, a protective resistance, a switch element, a detection resistance, and a variable power supply that are coupled in series. A low voltage side of the variable power supply is connected to a negative electrode of a power supply device that is a subject for observation. A computer turns on the switch element only upon leakage detection. Under the control of the computer, the variable power supply outputs the voltage of 0 (zero) volt for detecting the leakage on a high voltage side and the voltage of 10-odd volts for detecting the leakage on the low voltage side. A leakage current or a leakage resistance is determined by amplifying a voltage between both ends of the detection resistance. A reference potential of the leakage detection circuit is not the body ground but the negative electrode of the power supply device, thereby making it possible to configure the circuit in a relatively simple manner by using one detection circuit with one switch element having high voltage resistance. Therefore, it is possible to provide the leakage detection circuit in a relatively simple manner without using a plurality of switch elements having high voltage resistance.
|
