Signal regenerator circuit for paging receiver

Claim 1

In a selective paging receiver of the type having a power supply periodically activated for a short time period to energize the components of said receiver for enabling said receiver to receive and recognize a low frequency code signal formed from a plurality of serially received bits and amplified by a first amplifier for application to a signal regenerator circuit comprising: first and second transistors each having a base circuit, a collector circuit and an emitter circuit; a common impedance connected in series with each emitter circuit to define a differential amplifier configuration for said first and second transistors; a third transistor having a base circuit coupled to the collector circuit of said first transistor with said third transistor operated in saturation in response to signals above a predetermined level appearing in said first transistor collector circuit for transmitting constant amplitude signals each corresponding to the width of said bits; a fourth transistor having an emitter circuit coupled to the base circuit of said second transistor; means including a capacitor interconnected between the output of said first amplifier and a pair of serially connected unidirectional circuit elements coupled to the base circuit of said fourth transistor for transmitting to said fourth transistor base circuit a d.c. signal corresponding to the amplitude of each said received bit to control the conduction level of said first transistor, for controlling the width of each signal transmitted by said third transistor; another capacitor having a large time constant connected between the output of said first amplifier and said first transistor base circuit for transmitting a signal corresponding to each bit to said first transistor base circuit for enabling said first transistor to conduct for each received bit; first clamp means connected between said other capacitor and said first transistor base circuit for ensuring each signal transmitted by said other capacitor to said first transistor base circuit has a predetermined minimum amplitude whereby said first transistor conducts only in response to the signal transmitted by said other capacitor having said minimum amplitude; and other means connected intermediate said other capacitor and said first clamp means rendered momentarily conductive in response to each activation of said power supply for enabling said large time constant other capacitor to transmit a signal corresponding to said minimum amplitude substantially simultaneously with said activation.