Chopper frequency determination apparatus

摘要

A microprocessor controlled propulsion motor control apparatus for a passenger vehicle is provided, including a chopper apparatus having an interrupt clock to determine the frequency cycle of operation of that chopper apparatus. It is required that this frequency stay within a predetermined tolerance and not vary outside that tolerance. The output pulses from the microprocessor clock are counted between successive signals from the chopper interrupt clock in response to each occurrence of a determined operation condition of the passenger vehicle to determine that the chopper interrupt frequency is satisfactory.