TRANSISTOR_TESTER_2

Published:2009/7/12 20:28:00 Author:May | From:SeekIC

Useful for troub：eshooting and forchecking small-slgnal transistors having no markings Set four-pole five-position rotary switch S2 to SHORT(lowestpostion) before inserting transistor,then flip S1 back and forth，If meter shows any reading at all,reject transistor without further tests，rmeter stays at zero,set S2 to ICBO(conector-base current, emitter open). Discard transistor if reading is high foreither position of S1; modern transistors pass only nanoamperes, but older types may give noticeable reading, particularly if germanium. Repeat test for ICEO (collector-emitter current, base qpen), which should be greater than ICBO by factor approximating curtent gain (beta) of device, Modern silicon transistors may give no reading here. For final beta test, older types show 100 or less and modern transistors like 2N3391 have beta readings between 300 and 400. CR1 is 1N4603.-D. Cheney, Shirt Pocket Transistor Tester, Ham Radio, July 1976, p 40-42.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Measuring_and_Test_Circuit/TRANSISTOR_TESTER_2.html

Print this Page | Comments | Reading(3)