HP HP-Bench-Briefs-1980-07-08 free download

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ana aescrmea how to troubleshoot I I I I transistorized circuits. Incorporated into the text was a description of a simple in-circuit transistor checker that utilized the X-Y display capabilities of an oscilloscope. l a . NPN silicon transistor typical bias lb. PNP germanium transistor typical We have received many requests for conditions bias conditions copies of this article and especially Figure 1. Transistor bias examples information about the transistor showing the "on" condition checker. So, by popular demand, here is a repeat of "How to Troubleshoot In a PNP transistor, the base must saturated germanium transistor Transistorized Circuits Faster," by be more negative than the emitter in may have as low as 0.05 volts be- George Stanley, based mostly on his order for current to flow. tween its emitter and collector, book, Transistor Basics: A Short So "on" bias voltages for a transistor while a saturated silicon transistor Course. Copyright @ 1967, 1975 by can be summed up by referring to may have 0.5 volts or less between Hayden Book Company, Inc. All Figure 1 and the following two rules: these leads. rights reserved. T h i s material is printed w i t h the permission of - For a PNP, the base is negative, 0 Hayden Book Co., Inc., Rochelle the emitter is not quite as nega- n, Park, N.J. tive, and the collector is far more 72 0 negative. -76 0 Fundamental Characteris- - For an NPN, the base is positive, the emitter is not quite as posi- tics of Transistors tive, and the collector is far more % Before describing specific trouble- positive. 0 0 shooting tips, let's take a moment There is a distinct difference be- and review several important tran- tween a transistor being turned "on" Figure 2. Transistor bias example sistor characteristics. and being "saturated." When a tran- showing the "saturated" condition