Patent GB-784033-A (GB)
Title: Improvements in and relating to electronic counting arrangements
Inventor: HAWKES MAURICE
IPC: H03K29/00
Filed: 1955-12-23
Abstract: 784,033. Electronic counting apparatus. ERICSSON TELEPHONES, Ltd. Dec. 23, 1955, No. 36875/55. Class 106 (1). A predetermined counter comprises a plurality of multi-cathode tubes arranged in cascade and forming the orders of the counter, the pulses to be counted being applied to the lowest-order tube which, when the discharge arrives on a predetermined electrode, sends a pulse to the next higher order, and so on ; the output pulse from the highest order signalling that the predetermined number of pulses has been counted. The predetermined count required is set up on wafer-type switches SWA, SWB and SWC and transferred to multi-cathode tubes V3, V4 and V5 upon depression of a switch SWD (see below), the positions of the wafers for a count of 346 are shown in the Figure. Positive input pulses, generated in a known manner (e.g. by photo-cell) by the passage of pills or the like to be counted, are each applied via a capacitor C16 to the trigger of a tube V2 causing it to become conductive. The resulting negative pulse at its anode acts through a condenser C15 to extinguish a normally-conducting tube V1 and is also applied, via a preselected condenser in the group C10 ... C14, to the trigger of tube V1. After a time dependent on the time constant of this arrangement the tube V1 refires and extinguishes the tube V2. The negative pulse at the anode of V2 resulting from this brief period of conduction, serves to supply two staggered pulses to the guide electrodes Gdl, Gd2 of the " units " counting tube V3 and results in the movement of the glow discharge by one unit in a negative direction. Thus, in the example shown, the sixth input pulse will bring the glow to cathode KO, and the rise in voltage at this cathode will pass via a capacitor C3 to fire a tube V6 controlling the guide electrodes in the next multi-cathode tube V4 and step back by one unit the amount registered in the " tens " order. After forty-six input pulses the discharge in tube V4 will arrive on cathode F9 and the rise in voltage at this point will pass, via switch wafer SWA5, to the trigger of tube V7, firing the latter and stepping on the discharge in the " hundreds " tube V5. When three hundred and forty-six pulses have been received the discharge in tube V5 will arrive on cathode J9 and the rise in potential will be applied via wafer SWB3, to fire a gas-filled tetrode V8. When the tube V8 fires, relays A and B in its anode circuit are energized, with the following results : contacts A1 open to disconnect from earth all the cathodes KO ... K9, FO ... F9, JO ... J9 excepting those selected by the switches SWA, SWB and SWC respectively; contacts B2 are changed over to stop the feeding of the articles being counted, and to replace the filled container with an empty one; the closing of contacts A2 short-circuits the valve V8, and so extinguishes it in preparation for the next count. It will be seen that the initial operation of switch SWD also causes energization of relays A and B. When the predetermined number to be counted is a multiple of ten, or the second digit is a zero, the circuit operates in a slightly different manner, the zero digits in the units and/or tens orders being set up via switch wafers SWA4 and/or SWB6 and SWA6. Non-uniform denominations may be employed. Specification 712,215, [Group XL (a)], is referred to.