METHOD AND APPARATUS FOR INSTANT DIAGNOSIS OF IDENTITY OF PAIRED TRANSISTORS Russian patent published in 2012 - IPC G01R31/26 

FIELD: physics.

SUBSTANCE: differential stage comprising a reference and a test transistor is used. A mixture of controlled dc and ac voltage is applied in-phase across the reference and test transistors. An display in form of a double-beam oscilloscope is connected to the load resistors of the transistors. Voltage across the load resistors is viewed on the oscilloscope display. Minimum difference in the oscilloscope traces during synchronous movement thereof on the display indicates that the transistors are identical, otherwise the transistors are not identical. The display used can also be either a two-input comparator with a controlled threshold and a light-emitting diode at its output, or a needle galvanometer or a computer system.

EFFECT: simple and faster procedure for instant diagnosis based on both static and dynamic parameters.

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