Corona discharge intensity measurement device - has circuit sensing difference between peak and average voltage values

摘要

The undesirable corona discharge which appears irregularly is detected and measured for amplitude by a detector circuit. The peak and average values are determined both for positive or negative voltages. A corona discharge voltage is applied to a detector input terminal (10) and is connected to ground via a measuring resistor (11). The peak value is determined by a circuit (12) comprising an operational amplifier (17) with a diode (18) in the feedback path to form a peak detector. The amplifier drives a second amplifier (19) via a second diode (20) and memory capacitor (21). A leakage resistor (22) allows the measured value to evolve with time. The output of the circuit is applied to a subtractor (15) with an average value from a resistor (13) and capacitor (14) filter circuit. The difference between the two values is obtained at the output (24).