Patent ID: 7436173

Claim:
A method of measuring a movement distance, the method which comprises: providing a measurement configuration with a variable differential transformer assembly having a primary coil, first and second secondary coils, and an actuating element movably disposed for influencing a voltage induced into the secondary coils; connecting the primary coil to an alternating voltage; measuring a first input voltage at the first secondary coil and a second input voltage at the second secondary coil by scanning the first and second input voltages multiple times during a period of the alternating voltage; passing the multiple-scanned first and second input voltages to a digital logic module; determining a rectified average value of the first input voltage and of the second input voltage in the digital logic module; calculating a relative position of the actuating element from the average values of the first and second input voltages; connecting a monitoring unit to the digital logic module, to the multiplexer, and to a voltage generator, connecting the primary coil to the voltage generator, and producing with the monitoring unit an excitation voltage for the voltage generator, thereby correlating the excitation voltage in time with a clock cycle of the digital logic module and switching the multiplexer in correlation with the clock cycle of the digital logic module.