Delta modulation system

Claim 2

A delta modulation system comprising comparing means supplied with an input waveform for producing a differential signal, means for modulating a timing pulse sequence with said differential signal to provide an output pulse sequence, each pulse of said output pulse sequence being produced during a timing interval in response to said differential signal being of one polarity, means for generating a first level signal upon receipt of an output pulse during said timing interval and a second level signal in the absence of an output pulse during said timing interval, integrating means connected to said generating means and said comparing means, means connected from said integrating means to said generating means comprising means for differentiating said integrating means output and means for producing a distinct signal corresponding to the absolute magnitude of said differentiating means output, said generating means comprising first gating means jointly responsive to said distinct signal and receipt of an output pulse from said modulating means for producing a positive pulse proportional to twice said distinct signal magnitude and second gating means responsive to said distinct signal for producing a negative pulse proportional to said distinct signal magnitude.

Claim 3

A delta modulation system according to claim 1 further comprising a receiver having an input terminal and an output terminal responsive to said output pulse sequence from said modulating means for producing a replica of said input waveform comprising second means responsive to said output pulse sequence received at said input terminal for generating a third level signal upon receipt of an output pulse at said input terminal during said timing interval and for generating a fourth level signal in the absence of an output pulse at said input terminal during said timing interval, second integrating means supplied with said third and fourth level signals from said second generating means, means for coupling said integrating means output to said output terminal, second means connected between the said output terminal and said second generating means comprising second means for differentiating said second integrating means output and second means for producing another distinct signal corresponding to the absolute magnitude of said second differentiating means output, said second generating means comprising a third gate jointly responsive to said other distinct signal and an output pulse from said input terminal for producing a positive pulse proportional to twice said other distinct signal magnitude and fourth gating means responsive to said other distinct signal from said input terminal for producing a negative pulse proportional to said other distinct signal magnitude.