| 摘要 |
<p>PROBLEM TO BE SOLVED: To make performable the voltage detection through the use of an isolated amplifier without a trouble even under conditions in which the zero voltage of a voltage detecting line fluctuates without preparing an independent power source at the input part in a voltage detecting circuit, which detects a high voltage through the use of an isolated amplifier. SOLUTION: The voltage detecting circuit uses an insulated amplifier provided with an input part 1a and an output part 1b. The input part 1a is operated by the first power source and detects the voltage of voltage detecting lines 3 and 4 from load impressed with high voltage. The output part 1b is operated by the second power source E2 and transmits voltage detection values inputted from the insulated input part 1a to the outside. In this case, the input part 1a uses a common power source E1 as the above-mentioned first power source and is provided with a constant-voltage circuit D to crate operating voltage from the first power source E1, and the earth terminal of the input part 1a is connected to the zero voltage line 4 of the above-mentioned voltage detecting line.</p> |
