GB899502A - Circuit arrangements for generating impulses of rectangular waveform - Google Patents

Abstract

899,502. Transistor pulse circuits. FERNSEH G.m.b.H. March 25, 1960 [March 26, 1959], No. 10651/60. Class 40(6). In a pulse shortening circuit, the input pulse is applied through a capacitor to the base of a normally conducting transistor arranged in common emitter configuration so as to cut off the collector current, the current being restored before the end of the input pulse as a result of the charge or discharge of the capacitor through a base resistor. In the Figure, the application of a pulse to terminal 11 causes a cross-coupled monostable circuit 1, 2 to produce an output pulse C at the collector of 1. This is applied directly to an output terminal O and also through a shaping network 12, 13, 15 to a transistor 14. The effect of the resulting input waveform D and a wave H generated in the emitter circuit is to produce a delayed output pulse G, the amount of delay depending upon the setting of resistor 13. The pulse G cuts off transistors 20 and 26 which become conducting again before the end of pulse G when the respective capacitors 19 and 27 have charged sufficiently. Accordingly positive going pulses E and F are produced at the corresponding collector electrodes pulse E being longer than pulse F because the time constant of the capacitors (27, 28) is shorter than that of circuit 19, 21, and both pulses are delayed with respect to input pulse A because of the delay produced by the circuit of transistor 14.