GB777123A - Improvements in or relating to waveform generators employing transistors - Google Patents

Abstract

777,123. Transistor generating circuits. AUTOMATIC TELEPHONE & ELECTRIC CO., Ltd. May 17, 1955 [May 22, 1954], No. 15130/54. Class 40(6) In a circuit including two cross-connected transistors TRA, TRB, Fig. 2, at least one reactive component C is connected in the circuit in such a position that current flow through one transistor enables energy to be stored in the component to cause a sudden transition in the conducting condition of the transistors, whereupon the stored energy is released to cause a second transition. Assuming the capacitor C to be fully charged, transistor TRA is conducting and TRB cut-off. The capacitor C discharges until transistor TRB commences to conduct, the fall in collector potential being transmitted to the base of transistor TRA. Transistor TRA cuts off, the rise in collector potential being fed to the base of transistor TRB which conducts and commences to re-charge capacitor C. Capacitor C re-charges over the emitter-collector path of transistor TRB until the emitter current commences to fall, when, due to the regenerative action of the circuit transistor TRB cuts off and transistor TRA conducts again to complete the cycle. In a modification Fig. 4 a further capacitor C2 is connected between the collector of transistor TRB and the emitter of transistor TRA. By suitable choice of capacitors C1, C2 it is stated that a sine wave generator may be produced.