On Saturday, April 21, 2012 05:06:04 PM Jon Elson did opine: > gene heskett wrote: > > But then which of the > > > > other two are emitter and collector? > > This can usually be done with a DVM with diode test. Connect the > meter between C and E, and then connect a resistor, like 22K Ohm > between base and the suspected collector. Note the meter reading. > If it is about 0.6 V, you got it on the first try. If not, reverse the > C and E leads and repeat. Whichever way gives a markedly > lower voltage reading has the transistor connected right, and > the minus probe is on the emitter for NPN or collector for > PNP. > > Jon
Also correct Jon. But those results can, depending on the DVM, be a bit ambiguous. Verify that ones DVM works similar to this with a known good transistor. Those meters that only output something under a volt, may or may not work exactly, but they will be consistent for that meter. I like the open circuit voltage to be something above a volt as this 'gain test' is much more obvious. I had a Beckman/Waveteck at the tv station that only made about .85 volts at the probe tips, so that one took some getting used to & needed about a 10k resistor. 22k just barely came in range on most bugs. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> Be wary of strong drink. It can make you shoot at tax collectors and miss. -- Lazarus Long, "Time Enough for Love" ------------------------------------------------------------------------------ For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
