GB709214A - Improvements in or relating to electrical oscillation generators - Google Patents

Abstract

709,214. Pulse shaping and valve generating circuits. GENERAL ELECTRIC CO., Ltd., and IMM, R. C. June 9, 1952 [June 8, 1951], No. 13713/51. Class 40 (6) in an oscillator locked in phase by a synchronizing pulse train, unidirectional pulses are derived from an oscillator valve and added to phasing pulses derived from the leading and/or trailing edges of the input synchronizing pulse train and then fed to the oscillator valve, the sign of the phasing pulses being opposite from that of the unidirectional pulses. A circuit 16, Fig. 1, resonant at the pulse recurrence frequency is included in the anode circuit of oscillator valve 15 and feeds a valve 25 operating under Class C conditions. A connection from the join of resistors 26, 32 is made over resistor 27 and coupling capacitor 28 to a crystal 13 in a thermostatically controlled oven 14. The positive-going pulses from valve 25 maintain the crystal in series resonance and thus provide the drive for valve 15. A pulse modulated train, fed in at 1 to a valve amplifier 2 is sliced by diodes 4 and valves 5 in the manner described in Specification 706,715, a phase splitter valve 7 giving the outputs, Figs. 2(a) and (c) at the cathode (A) and anode (C). Differentiating circuits 36, 37 and 33, 34 produce the waveforms, Figs 2(b), 2(d), and rectifiers 39, 38 suppress the positive-going pulses. The pulses are added to the positivegoing pulses from valve 25 at the point E to give the waveform, Fig. 2(e). The phase of the locally produced pulses shifts until the phasing pulses occur equidistant from two successive local pulses. A sine wave output is made available over the tuned circuit 69. A rectifier 44 prevents interaction between the oscillator and phasing pulse circuits. Reshaped output pulse train. -The signal occurring at the cathode (A) of valve 7 is fed to a gating circuit comprising biased diodes 61 which are caused to conduct by the locally generated pulses fed over transformer 47 at the centre of each possible pulse period. The storage capacitor 64 is thus charged or discharged at the occurrence of each pulse either to the level of a pulse or the zero datum level. The resulting pulse train, Fig. 2(f), is fed out over cathode follower 68.