GB916259A - Deviation counter - Google Patents

Abstract

916,259. Electric selective signalling systems. BECKMAN INSTRUMENTS Inc. June 16, 1961 [Sept. 2, 1960], No. 21774/61. Class 40 (1). [Also in Group XIX] Apparatus for measuring deviation from normal of a frequency or time-duration between events comprises a counter which can be set to a predetermined number and is then operated in reverse, the attainment of zero changing the counter to forward operation. To measure frequencydeviation switches 12 are set to upper position and the normal frequency N 1 is set up over selectors 31 on counter 30. The test frequency is applied through input 10 to signal gate 17 which is opened through gate control circuit 18 and digital divider 19 by clock pulses from 16 for a predetermined time. During this time the test frequency runs counter 30 in reverse. If a number remains in the counter at the end of the operation it indicates by how much the frequency falls short of the norm. On the other hand if the counter 30 reaches zero a control circuit 32 operates to cause the counter to operate forwardly. The final registration then indicates excess. The sign of the final registration is indicated by the condition of control circuit 32. To measure deviation from a standard time for a number of input pulses, the standard time in terms of clock pulses is set up at 31 and the switches 12 are reversed. Selectors 31 are in the form of a 4-back switch for each denomination, Fig. 4, whereby a combination of leads 131-138 is marked to set up a binary-decimal cascade counter, Fig. 5. According to whether control circuit marks lead 34 or 35 so one or the other side of each stage is connected to the input of the next to provide forward or reverse counting. Transfer and resetting is of known type.