Improvements in and relating to oscillation generators known as multivibrators

Abstract

Abstract 456,840. Valve generating circuits. WHITE, E. L. C., 32, The Rise, Hillingdon, Middlesex. March 12, 1935, No. 7730. [Class 40 (v)] In a multi-vibrato] circuit for deriving im pulses of a desired fre quency and duratior from applied impulses of a different frequency or duration, one of the coupling-circuits of the pair of valves. has a time constant greater than that of the other coupling-circuit and much greater than the period of the applied impulses. As shown, a pair of triode valves V1, V2 are provided with anode resistances R3, R4, of which the latter is preliminarily adjustable, grid leak resistances R1, R2 and reciprocal coupling- condensers C1, C2. The input is applied through a condenser C4 across the anode and cathode, or grid and cathode, of the valve V2, and the output is taken through a condenser C3 from the anode and cathode of the valve V1. The time constant C1, R1 may be from 20 to 100 times the period of the derived impulses and may be fixed, and the effective time constant C2, R2 is variable by means of a variable resistance R2 or by varying a positive bias applied to the grid of the valve V2. If the time constant C2, R2 is less than the period of the applied impulses, the impulses derived from the condenser C3 are of the same periodicity, but their duration varies with the setting of the adjustable resistance R2. If the time constant C2, R2 lies between n times and n+1 times the period of the applied impulses, the output period is n+ 1 times the input period. Tetrode, pentode, or other multi-grid valves may be employed, the input impulses being applied to a grid other than that used for the reciprocal coupling, Figs. 2 and 3 (not shown).

Inventors

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