Improvements to the measurement instruments of the type with a comparison

摘要

1,105,369. Comparison circuits. COMPAGNIE FRANCAISE THOMSON-HOUSTONHOTCHKISS BRANDT. Dec. 22, 1965 [Dec. 23, 1964], No. 54424/65. Heading G1U. In a circuit in which a number of input signals V 1 , V 2 , V 3 are compared by finding the difference between each pair and feeding the difference to trigger circuits e.g. 3, 4, the triggering threshold is constantly proportional to the average of the input signals being compared. The average value of the input signals produced at D is fed to a first potentiometer 8 and, via an inverter 11, to a second potentiometer 12 to produce positive and negative threshold reference voltages for the trigger circuits, e.g. 3, 4. If for example V 1 differs from V 2 and V 3 circuit 3 or 4 will trigger (depending on whether V 1 is greater or less than V 2 ) to feed an output to logic circuit 5. An output from 5 is then fed back to gate 6 to close the channel from V 1 to the averaging circuit.