Patent GB-768653-A (GB)
Title: Improvements in or relating to electrical gas discharge tube circuits
Inventor: BEESLEY JOHN HENRY
IPC: H03K23/82
Filed: 1954-02-05
Abstract: 768,653. Electronic counting apparatus. GENERAL ELECTRIC CO., Ltd. Jan. 31, 1955 [Feb. 5, 1954], No. 3461/54. Class 106 (1). A pulse counting or distributing circuit comprises a chain of gas tubes, the signals to be counted or distributed being connected to at least two input leads and adjacent tubes of the chain being interconnected and to said input leads so that when one of the tubes is.conducting a striking voltage is applied to the strike electrode of the following tube in the chain when at least a predetermined voltage is applied to a particular one of the said input leads. The inter-tube connections each comprise a coincidence circuit having one input from the cathode resistor of a gas tube and a second input from one of the input leads. Figs. 1 and 2 show a pulse counting or distributing circuit comprising a chain of cold cathode gas-discharge tubes 1, 2 ... N. Each tube of the chain has its cathode connected via a resistor 10 and rectifier 11 to the strike electrode of the following tube. Input pulses to be counted are connected to leads 12, 13 which are connected alternatively to consecutive tubes in the chain. If, for example, tube 1 is conducting at any instant, which may be brought about by applying a positive potential to its strike electrode 5 then all other tubes are rendered non-conducting by the voltage drop across the common anode resistor 8. When tube 1 is conducting the voltage drop across its cathode load network renders rectifier 21 conducting and the voltage at the strike electrode 5 of the succeeding tubing in the chain is insufficient to cause that tube to fire. When however a positive voltage is applied to the input terminal 14 rectifier 21 is cut-off and the rise in voltage at the strike electrode 5 causes tube 2 to fire and tube 1 to be cut-off. The next input pulse applied at terminal 15 to lead 13 will cause the succeeding tube to fire and all previous tubes to be cut-off. Output pulses may be derived across the cathode load terminals 28, 29, &c., or the circuit may function as a pulse counting circuit. In a modification the tubes are connected in a chain instead of a closed ring. If two or more counting circuits are required to be connected in cascade, individual connections may be made from the input lead of one such gas tube circuit to 'a different output of a preceding circuit or more than one output may be connected to the same input lead if blocking rectifier -elements are included in - the said connection. The pulse input to terminals 14 and 15 may be derived from any suitable source such as, for example, a bi-stable trigger circuit. When a closed chain of gas tubes is used the number of tubes must be a multiple of the number of input leads. The signals to be counted or distributed must be a multiple of the number of input leads. The signals to be counted or distributed must be positive voltages of an amplitude at least equal to the striking voltage of any tube. The rectifier elements are preferably of the solenium type. Specification 765,680, [Group XL (c)], is referred to.