Apparatus and method for calibration of transmission shifters

The present invention relates to electrically actuated shifting mechanisms for automated mechanical transmissions. Specifically, the invention relates to an electronic circuit used to compensate for variations in the calibration of transmission shifters in automobiles or other vehicles as a result of temperature variations in the related electronic circuitry. The invention teaches an electronic circuit and method for providing a feedback calibration reference signal to a microprocessor from a power supply circuit that allows the microprocessor to account for variations in power supply temperature and resulting measurement variations during the shifter calibration process. The present invention relates to an electronic control circuit and method for calibrating a transmission shifter and compensating for temperature variations. The electronic control circuit includes a power supply circuit comprising a bias voltage supply and a voltage surge protection circuit; at least one position sensor that receives a surge-protected output bias voltage from the power supply circuit; and a microprocessor that receives one or more position values from the position sensor relating to the physical position of the transmission shifter. The power supply circuit provides a calibration reference signal to said microprocessor. The voltage surge protection circuit protects the calibration reference signal against a surge voltage condition.