DRIVER CIRCUIT FOR AN ELECTRIC VEHICLE AND A DIAGNOSTIC METHOD FOR DETERMINING WHEN A FIRST VOLTAGE DRIVER IS SHORTED TO A LOW VOLTAGE AND A SECOND VOLTAGE DRIVER IS SHORTED TO A HIGH VOLTAGE

摘要

A driver circuit and a diagnostic method are provided. The driver circuit includes a first voltage driver, a second voltage driver, and a microprocessor. The microprocessor generates a first pulse width modulated signal to induce the first voltage driver to output a second pulse width modulated signal to energize a contactor coil. The microprocessor sets a first diagnostic flag equal to a first value if a first filtered voltage value is less than a first threshold value. The microprocessor sets a second diagnostic flag equal to a second value if a second filtered voltage value is greater than a second threshold value. The microprocessor stops generating the first pulse width modulated signal to de-energize the contactor coil if the first and second diagnostic flags are set equal to the first and second values, respectively.