Ten-bit resolution PCM encoder (falling sphere experiment)

A miniature PCM encoder with 10 bit resolution was developed for use on the falling sphere experiment. Use of CMOS logic elements and an internal power supply resulted in a compact light-weight unit with minimal power demand suitable for use in the 10 inch diameter instrument, for measurement of atmospheric density. A bi-phase level coded system is used, with data input capability of fifteen bipolar (plus or minus 5 vdc) analog data lines, each sampled 125 times per second. Subcommunication of up to seven housekeeping monitors (each 0 to -5 vdc, analog level) is also included. Details of circuit design and test evaluation of the prototype unit are covered; the report is written to serve as a technical manual for the equipment, and also covers an associated test set.