Patent GB-738732-A (GB)
Title: Improvements in or relating to gaseous electric discharge apparatus
IPC: H01J17/48
Filed: 1950-12-15
Abstract: 738,732. Digital electric counting apparatus. WESTERN ELECTRIC CO., Inc. Dec. 15, 1950 [Dec. 15, 1949; Dec. 15, 1949], No. 30646/50. Class 106 (1). [Also in Group XL (a)] A counting arrangement comprises a cold cathode gas-filled electric discharge tube, wherein a glow discharge is stepped in either direction along electrodes mounted in a row which may be rectilinear, circular, or of other configuration, the arrangement being thus adapted to register the algebraic sum of groups of pulses. The electrodes may also be arranged in a rectangular array in a device adapted to add or subtract complex numbers or vectors, or may be arranged in a three-dimensional rectilinear array. In a circular embodiment, Fig. 1, the discharge tube 10 comprises cathodes 11 and 12 connected by rings 15 in groups A and B, and auxiliary electrodes 13 and 14 connected in groups C and D. A common anode 16 is mounted opposite the cathodes and uniformly spaced therefrom. The A cathodes are biased negatively with respect to the B cathodes by a source 17 and a pulse source 18 is provided for driving the B cathodes negative with respect to the A cathodes. All the cathodes are biased negative with respect to the anode 16 by a source 19, the anode-cathode potential being somewhat above the sustaining voltage. The C and D electrodes may be connected selectively to either the A or B cathodes by means of a switch S. With the switch S in the position shown and assuming a discharge sustained at the A cathode 11<SP>1</SP>, the D electrodes are tied to the B cathodes, and the C electrodes are tied to the A cathodes, so that a pulse from the source 18 drives the D electrodes and B cathodes negative relative to the A cathodes and C electrodes. Thus, D electrode 14<SP>1</SP> and B cathode 121 are driven negative relative to A cathode 11<SP>1</SP>, whereas C electrode 13<SP>4</SP> will be at substantially the potential of A cathode 11<SP>1</SP>. The discharge thus transfers to the D electrode 14<SP>1</SP> and owing to the construction of the electrodes (see Group XL (a)), whereby the cathodes have a greater efficiency as glow discharge elements than the auxiliary electrodes, will then transfer to the B cathode 12<SP>1</SP>. Upon cessation of the pulse, the auxiliary electrode 13<SP>1</SP> and cathode 11<SP>2</SP> become negative relative to the cathode 12<SP>1</SP>, whereas the electrode 14<SP>1</SP> remains at substantially the same potential as the cathode 12<SP>1</SP> and the discharge transfers to the auxiliary electrode 13<SP>1</SP> and from there to the A cathode 11<SP>2</SP>. By changing over the switch, the discharge can be stepped in the opposite direction from A cathode 11<SP>1</SP> to A cathode 114. Fig. 2 shows a modification in which the C and D electrodes are connected permanently through resistors 21 to the A cathodes and the B cathodes are selectively associated with either the C or D electrodes by the switch S. The operation is essentially the same as in the case of Fig. 1. A rectangular embodiment, Fig. 5, adapted for bi-directional stepping of the discharge in either of two co-ordinate dimensions comprises A cathodes A1 to A9 and B cathodes, and C and D electrodes bearing a subscript h or v indicative of whether the particular electrode is involved in horizontal or vertical stepping. Electrodes similarly identified are connected together electrically to a respective one of the terminals 1 to 7 ofthe switch S, which is operated as follows: To step the discharge to the right; connect 5 to 3 and 7 to 1, which is operated as follows: To step the disdischarge to the right ; connect 5 to 3 and 7 to 1, and apply pulses to 3. To step the discharge to the left; connect 5 to 1 and 7 to 3, and apply pulses to 3. To step the discharge downwardly; connect 4 to 2 and 6 to 1, and apply pulses to 2. To step the discharge upwardly; connect 4 to 1 and 6 to 2 and apply pulses to 2. Additional cathodes and auxiliary electrodes may be provided to obtain bi-directional stepping in any of three dimensions. Specifications 708,424, 738,792 and 738,810 are referred to. -