MEASURING INSTRUMENT OF RF SIGNAL DELAY IN PARTIAL DISCHARGE MONITORING

摘要

PURPOSE: An electromagnetic wave time delay measuring apparatus of a partial discharge monitoring device is provided to accurately measure time delay of four channels without using an expensive four-channel digital oscilloscope and a digital filter. CONSTITUTION: An electromagnetic wave time delay measuring apparatus of a partial discharge monitoring device includes an electromagnetic wave and voltage converting means (302), a voltage comparing means (303), a sequential input converting means (304), a time and digital converting means (305) and a microprocessor (306). The electromagnetic wave and voltage converting means converts an electromagnetic wave signal of an input channel into a direct current having a log dBm level. The voltage comparing means compares a voltage outputted from the electromagnetic wave and voltage converting means and a reference voltage and outputs a digital value of a complementary metal-oxide semiconductor (CMOS) level. The sequential input converting means receives the output of a three-channel voltage comparing means which is different from the output of the voltage comparing means and generates a sequential input arranged by a command of the microprocessor. The time and digital converting means outputs time difference of four channels which are sequentially inputted by inputting the output of the sequential input converting means. The microprocessor controlling a control signal is included in the time and digital converting means and the sequential input converting means. [Reference numerals] (301) Four-channel electromagnetic wave input; (302) Log amp; (303) Voltage comparing means; (304) Sequential input converting means; (305) Time and digital converting means; (306) Microprocessor