Abstract: Methods, circuits and computer program products are presented herein. The method includes isolating a ripple waveform from a current signal originating from a brushed direct current motor (BDCM). The method includes determining the wave count of the ripple waveform. The method includes determining a position of a movable structure operably coupled to a shaft of the BDCM according to the wave count of the ripple waveform. The present technology may be practiced without discrete capacitor components in high pass filtering aspects of the disclosed circuit. The methods, circuits and computer program products can be implemented to accurately determine a rotational position of a shaft of a BDCM and also position(s) of mechanism(s) coupled to the shaft without requiring any external sensors or other components for this purpose other than the disclosed circuits.

Abstract: A touch panel or screen has a serpentine transmission line fabricated on a substrate, e.g., printed circuit board, LCD, plasma or LED screen, etc., and has a constant impedance. Touches to the touch panel will cause changes of impedance of the transmission line at the locations of the touches. Time domain reflectometry (TDR) is used for determining the locations of the changes of impedance of the transmission line by accurately measuring the return pulse times at the source of a plurality of pulses, and then converting the return pulse times to X-Y coordinates of the touch panel or screen.

Abstract: A touch panel or screen has a serpentine transmission line fabricated on a substrate, e.g., printed circuit board, LCD, plasma or LED screen, etc., and has a constant impedance. Touches to the touch panel will cause changes of impedance of the transmission line at the locations of the touches. Time domain reflectometry (TDR) is used for determining the locations of the changes of impedance of the transmission line by accurately measuring the return pulse times at the source of a plurality of pulses, and then converting the return pulse times to X-Y coordinates of the touch panel or screen.