Abstract: An optic position sensor provides a data encoding method which improves the resolution capability of the sensing system. The data pattern of the sensor comprises a series of data signals having a start bit, digital data bits, an analog bit region (12) and a stop bit. The digital data bits may be a Manchester Encoded, Gray Coded data signal pattern. The analog data bit region (12) comprises a vernier track (10) which will produce a signal peak that moves linearly with position. The detection of the position of the vernier track (10) or bit relative to its range or region (12) provides a measurement of the percent of travel that has occurred within and between the discernible resolution of the digital data bits of the data signal, to provide resolution capability of approximately one part in sixteen thousand.

Abstract: A preamplifier for a magnetic record reproducing system includes a differential amplifier construction wherein the input stage may be configured as a differential cascode arrangement for minimum noise at the lower frequency range or to be configured as an emitter-follower for maximum input impedance at the upper frequency range. The structure allows the amplifier to respond to very high frequencies, on the order of 4 MHz, without the introduction of an undesirable phase shift in the reproduced signal.