Improvements in or relating to thermionic valve counter circuits

Abstract

Abstract 584,422. Pulse counting circuits. TAYLOR, S. M. Dec. 30, 1944, No. 26192. [Class 40 (v)] [Also in Group XIX] In a counter circuit for producing an output pulse for every 2n + 1 input pulses, an electronic switch passes the input pulses to a series of n scale-of-two units forming a scale of 2n chain, an output pulse from the chain operating the switch to connect the input circuit to the output circuit to produce a pulse coincident with the 2n + 1 input pulse, the output circuit restoring the switch to the normal position. A further scale of two unit may precede or follow the circuit giving a 2(2n+1) counter, or scale of ten, when n=2. The scale of two units, Fig. 1, comprises a trigger circuit or multivibrator biassed to have two stable states with either valve 1 or valve 2 conducting, the other being cut off. A negative pulse, applied to the grids of both valves, reverses their state, the positive pulse appearing in the anode circuit of vavle 2 when it is cut-off, by alternate negative pulses, causing normally non-conducting valve 3 to pass current and generate a negative pulse on its anode. The scale-of-ten counter, Fig. 2, comprises a scale-of-two unit consisting of double triode valve 10 feeding pentodes 12, 13 which act in a similar manner to valve 3, the valve 13 normally being cut off at the suppressor grid. Negative pulses from valve 12 feed scale-of-two units 14, 15 the output from which reverses the state of trigger valve 16 which cuts off valve 12 and allows valve 13 to conduct. The next pulse from valve 10 passes through valve 13 to restore the trigger device 16 and generate an output pulse through triode 17. When valve 16 is restored the rise in suppressor grid potential of valve 12 is delayed due to the condenser 18 to avoid passing an extra pulse to units 14, 15.

Inventors

No inventors recorded.

Bibliographic Details