GB592533A - Improvements in or relating to electronic devices and control means therefor - Google Patents

Abstract

592,533. Pulse counting circuits. NATIONAL CASH REGISTER CO. May 19, 1944, No. 9736. Convention date, Nov. 7, 1940. [Class .40 (v)] Apparatus for counting electrical impulses comprises a plurality of gas-discharge tubes connected in series to become conducting one at a time in succession in response to impulses applied to the control grids of all the tubes, each tube having a current tapping electrode, the rise of potential of which, when the tube fires, is applied to the grid of the tube next in the series to prime it, the firing of a tube causing any other conducting tubes to be extinguished. As shown in the Figure, tube I is fired by temporarily applying a positive potential to its control grid 32 and current tapping member 22, and so causes the anode potential to fall and the current tapping member and thus the control grid of tube II to become more positive. When a positive impulse is applied to all the control grids through a conductor 65 and condensers 66, tube II, alone will fire since its grid is at a higher potential than the rest. The anode potential of tube II will then drop, producing a negative impulse on conductor 70 which is impressed through condensers 63 on all the anodes, so that the anode of tube I, and any other tube which happens to be conducting, is driven more negative than its cathode, thus extinguishing the tube. The potential of the current tapping member of tube II will rise and so cause a further tube, or tube I if the tubes are connected in a chain by conductor 82, to fire when the next impulse is received. To give an indication as to which tube is conducting, the current tapping members of the tubes are connected to electronic relays, such as tube III, each of which is conductive when the voltage of the tapping member rises to operate an indicating mechanism. Specification 592,532 is referred to.