GB694564A - Electronic pulse distributing and counting apparatus - Google Patents

Abstract

694,564. Cathode-ray tubes. GLOESS, P. F. M., and GALLAVARDIN, J. A. M. L. July 1, 1949 [July 7, 1948], No. 17422/49. Class 39(i) [Also in Groups XIX and XL(c)] The cathode-ray tube of pulse distributing and counting apparatus has a plurality of secondary emitting targets each connected to a set of deflector plates and to an independent leakage circuit which fixes the potential applied to the plates. The electron gun projects a beam through an anode 19, a set 4 of deflecting plates 8, 9, and an additional deflecting system comprising two coaxial cylindrical electrodes 5, 5<SP>1</SP>, on to a set of strip targets such as 6, 10 lying on or adjacent to a luminescent screen 7. The plates 8, 9 are arranged as opposite pairs, one plate of each pair being connected to one target strip and the other plate to a target strip in a diametrically opposed position. The target strips are regularly distributed and the outside end of each strip is situated on the radius crossing the inside end of the adjacent strip. The plates 8, 9 are connected through resistances 17, 17<SP>1</SP> to the negative pole of a voltage supply 18, the positive ends of which is connected to earth and to the anode 19, the latter also being connected to a wall coating 24 and to the inner cylinder 5 and through a resistance f to the screen 7. The outer cylinder 5 is connected to the incoming pulse terminal I, a central target 21 is connected by a strip 16 to the first target 6 and when the electron beam impinges on target 21, secondary electrons are emitted and current flows in resistance 17 to apply a positive potential to plate 8 and cause the impact spot of the beam to move up the strip 16 to the target 6. If now a positive pulse is applied to terminal I 1 , the beam is deflected radially and reaches the outside end of the adjacent strip 27. The secondary emission results in a potential being applied to the corresponding deflecting plate and the impact spot moves down to the other end of the strip which is the equilibrium position determined by the constants of the circuit. The impact spot overlaps the target strip so as to impinge on the fluorescent screen. With the incidence of further positive pulses, the spot moves from strip to strip. The positive potential produced when the beam hits a target strip may be used to trigger the control relays of a calculating machine, and that on the starting target 6 is used to actuate in a cascade counter a further tube acting as a counter of tens and so on. The pulse is applied to the second tube through a differentially-acting time constant circuit comprising a condenser and a resistance. The primary negative charge of the beam instead of secondary emission may govern the potential of the deflecting plates, the connections to the plates being reversed. The subtraction and addition of pulses is provided by the modification, Fig. 6, in which each strip overlaps the next one by half its length. The equilibrium position for each target strip is in the middle, and positive and negative pulses give outwards and inwards movement of the spot to adjacent targets respectively. Target 48 is the origin and the following target 49 is connected to the central starting electrode of the tube. Two auxiliary target electrodes 62, 63 are provided when connected as decade counters and, in subtraction, the spot when on target 48 jumps to the lower target 47 and reaches 63 to give a control impulse which is applied to the commutating electrode of the lower tube. Similarly in passing from the " nine" target 47 to the origin target 48 a positive pulse is yielded by auxiliary target 62 and is applied to the commutating electrode of the higher tube. The inner system of electrodes 5, 51 giving pulses can be replaced by external means varying the beam velocity. A reliable counting speed of 666.000 is stated to be obtained. The Specification, as open to inspection under Sect. 91 also comprises the subject-matter of Fig. 7 (Cancelled) in which flat insulating rings 70, 71, 72, 73, 74 support the deflecting plate 8, the metal connecting rods 8, the anode 19, the deflecting electrodes 5, 5<SP>1</SP> and the targets. The targets are of barium, strontium or other alkaline earth oxide on a nickel base. The resistances 17 and the currents flowing in the various circuits are specified. This subject-matter does not appear in the Specification as accepted.