Peak-to-peak alternating current signal detector

Claim 1

An electrical circuit for supplying a direct current output responsive to an alternating current input comprising a rectifying network comprising a series circuit including a first capacitor, a diode, and a second capacitor, amplifier means for providing a positive current alternation to said network responsive to a corresponding positive alternation of said input comprising a first transistor, a source of potential connected in the emitter-collector circuit of said first transistor and means for applying a predetermined bias to said first transistor, said first and second capacitor being charged during said positive alternation on said network along a path including said series circuit and said emitter-collector circuit, said bias being determined as of a magnitude less than required for the generation by said amplifier means of current to discharge said first capacitor responsive to a negative alternation of said input, means for providing a negative current alternation to said network comprising a second transistor having its emitter-collector circuit connected across only said first capacitor for discharging only said last-mentioned capacitor and only by current conducted in said emitter-collector circuit of said second transistor, and output terminal means connected to said series circuit at the output of said diode. 2. An electrical circuit as claimed in claim 1 also comprising means for biasing said second transistor comprising a voltage divider having an output tap connected to the base of said second transistor.