A Multipurpose Electronic Switch for Analog Computer Simulation and Autocorrelation Applications

A system of four diodes in a series-parallel connection is combined with dc operational amplifiers in order to accomplish a variety of computational operations. The diode circuit is equivalent to a SPST switch survey or a voltage pulse. When inserted in series with the input of an amplifier or an analog memory, the switch makes possible waveform sampling or waveform quantizing of the input voltage. Other functions, such as the fast discharge of an integrator, are also achieved. A very significant application of the diode switch in computer circuitry is its use in combination with a multiplier and a storer (a bank of integrators) in order to obtain autocorrelation or cross-correlation of messages after they have been translated into voltages. A commutator or a ring counter is employed to provide the switching pulse. The correlator has the advantage of generating the correlation function concurrently with the message without necessitating previous recording and repeated playback.