Measuring circuits used in an automatic transistor tester

A machine which is capable of testing, sorting and measuring all the significant parameters of germanium r.f. alloy transistors at a rate of 1200 transistors per hour is described. Since the machine uses essentially only one test head, each measuring circuit, which is mounted on a printed circuit card, is connected in turn to this test head by means of dry reed relays. The paper describes how 10 d.c. parameters and 7 a.c. measurements and tests are carried out on each transistor and explains some of the circuits in detail. In addition the relative merits of single test station and multi-test station machines are discussed.