A transistorized pulse code modulator

A pulse code modulator is described in which transistors are the only active circuit components. The functions of quantizing and encoding the signal are performed entirely by semiconductor diodes, using transistor amplifiers where necessary to increase the signal level. The readout is obtained from a set of "and" gates, each gate having as one of its inputs an output from the encoding system, and as the other input, a pulse obtained from a time delay circuit to assure sequential operation. The system produces a three digit binary code at a sampling rate of 5,000 cps.