AN EQUIPMENT TO PROVIDE FREQUENCY CLEARING OF METALLISED PLASTIC FILM CAPACITOR

摘要

The present invention relates to the frequency clearing of a metallised plastic film capacitor by applying Alternating Current (AC) voltage in the form of pulses to clear conducting path of the metal plate of capacitor. Equipment to provide frequency of metallised plastic film capacitor is disclosed. The equipment comprises : an AC power supply unit, control unit, output unit and Alternating Current (AC) to Direct Current (DC) converter. An AC power supply unit generates 0 to 230 V variable AC power being further step up to 1250V AC variable in steps as per the requirement of voltage. The control unit provides a fixed number of pulses required for the frequency clearing operation, The control unit comprises : digital two digit counter which counts and allows desired number of sinewave cycles pulses at the output, settable from 1 to 99; a flip-fftvp having "SET" and "RESET" terminals, to start and reset the timer; a pair of monostable multivibrator for providing square wave pulse outputs for setting and resetting the flip flop; foot switch is connected to ''SET' terminal of the flip flop through one monostable multivibrator to start the counter; count over output is connected to reset terminal of the flip flop through the second monostable multivibrator to stop and reset the counter; solid state switch to ensure that only fixed number of pulses being decided by the control unit to be given to output unit. The output unit provides an amplitude controlled AC voltage pulses to the capacitor for frequency clearing purpose, said output unit is connected to control unit, said output unit consists of variable transformer unit for providing variable amplitude AC voltage pulses. The AC to DC converter is connected to AC power supply unit for providing DC power supply to control unit and output unit. Also a method of manufacturing a metallised plastic film capacitor with frequency clearing as one of the step is disclosed.