transistor match-maker

4-04 — elektor april 1981 "transistor match-maker" A transistor tester for finding matched pairs. "Oh no, not another transistor tester!" may welt be several readers" initial reaction. Don"t worry, this article is designed to save you and your eyes hours of strain and boredom. The device is capable of picking matched transistor pairs from a whole pile of "possibles", and all within seconds. Two transistors will be "matched" if their base/emitter voltage and their current amplification are the same. The degree of accuracy may range from "roughly the same" to "identical" (1 %) and can be adjusted, as required. It really is an indispensable aid when suitable matched transistors are needed for differential amplifiers, or temperature sensors. Finding matching transistors is a highly unpopular and tedious occupation. Nevertheless, it is one of those jobs that just have to be done from time to time, as such transistor pairs are often used in differential amplifiers and in particular, o...