Regenerator for pulse code modulation systems

Claim 1

A PCM regenerator comprising: an input transformer, an amplitude decision device connected to said input transformer, a phase discriminator and a time decision device connected to the outputs of said amplitude decision device, a pulse amplifier connected to the output of said time decision device, a pulse shaper connected to the output of said pulse amplifier, a pulse generator, a low pass filter connected to the output of said phase discriminator, said pulse generator connected to the output of said low pass filter, the output of said pulse generator connected to said time decision device and to said phase discriminator, said amplitude decision device containing one signal path for positive signals and one signal path for negative signals, a pair of differential amplifiers in said signal paths and each consisting of two transistors and operated in emitter connection, with the base of one of said two transistors of each connected to opposite ends of the said secondary input transformer, the output of one of said differential amplifiers connected directly to the input of said time decision device, a pair of switch-back diodes, each connected to an output of said time decision device and their outputs connected to the commonly connected collectors of said ones of said two transistors, a current generator having first and second input terminals and an output terminal, a first Zener diode connected to a first input of said current generator, a pair of D flip-flop circuits having setting D, Q and triggering terminals, and said current generator contained in said phase discriminator, the setting terminal inputs of each of said pair of D flip-flop circuits connected to the output of one of said differential amplifiers of said amplitude decision device, the D terminal inputs of said two D flip-flop circuits connected to ground fourth and fifth diodes and the Q terminal outputs connected to one side of said fourth and fifth diodes, a resistor connected to said second input terminal of said current generator and to the other sides of said fourth and fifth diodes, an additional differential amplifier contained in said current generator, a second Zener diode connecting said additional differential amplifier to said first input terminal of said current generator, and said differential amplifier comprising two npn transistors with their outputs connected to said current generators output terminal, said current generator containing an amplifier stage which is operated in emitter connection and consists of a pnp transistor with its input connected to the second input terminal of said current generator and its output connected to said input terminal of said current generator, a low pass filter connected to said output terminal of said current generator, a quartz oscillator which is said pulse generator connected to the output of said low pass filter and its frequency controlled thereby, and a rectangular shaper receiving the output of said oscillator and supplying an output to said time decision device and to the triggering terminals of said pair of D flip-flop circuits of said phase discriminator.