| 摘要 |
PURPOSE: To monitor the balance of a DC voltage with ground potential by grounding the center tap of a potential dividing circuit between two lead wires, comparing a first positive part voltage with a second negative part voltage and comparing a second positive part voltage with a first negative part voltage. CONSTITUTION: This device has three resistors R1a, R2a, R3a; R1b, R2b, R3b between two lead wires a, b and the point of ground potential 0V, the resistors respectively are a pair and same, and two positive part voltages U1a, U2a and two negative part voltages U1b, U2b are extracted. During regular operation, a DC voltage U balances with ground potential between the lead wires a, b, and the amplitude of the voltages U1a, U1b is equal and the amplitude of the voltage U2a, U2b is equal. When there is unbalance due to disturbance, an output is obtained from operational amplifiers OP1, OP2. |
