| 摘要 |
PURPOSE:To use a lower-cost amplifier for the titled device by inserting a voltage dividing resistance circuit, which has a prescribed voltage dividing ratio, into the grounding wire and by connecting both ends of the resistor having smaller resistance values to the device. CONSTITUTION:A voltage dividing resistance circuit consisting of resistors 8 and 9 are inserted into the grounding wire EL, and an insulation amplifier 7 is connected to the output side of the outputting resistor 3. The output of this amplifier is applied to the resistor 9 which has a smaller resistance value. If the resistance value of the resistor 9 is set to, say, 1/20 that of the resistor 8, the voltage across the resistor 9 can be suppressed to about 10V, even if a higher harmonic voltage of about 200V is induced across the voltage dividing circuit by the rectifier circuit 6. The amplifier which can withstand such a voltage is easily and cheaply available. The harmonic voltage across the resistor 9 is not transmitted to the outputting resistor side, because the amplifier 7 lies in between. The higher harmonics which have occurred at the detecting resistor 4 is removed by the filter provided on a measuring device 2. Through this constitution, a lower-cost amplifier is available. |
