Transistor Question

Yes I do. I'm going to assume that the base-emmitter drop is 0.7 Volts (can be changed at anytime). Vb=Ve+0.7 ib=(15-Vb)/1k ie=(Ve-0)/0.5k ie=(Beta+1)*ib therefore (Ve)/0.5k=(Beta+1)*((15-Vb)/1k) (Vb-0.7)/0.5k=(Beta)*((15-Vb)/1k) Where Vb = base voltage Ve = emitter voltage ib = base current ie = emitter current Beta = internal gain of Xsistor

And the rest is trivial.

np

Dwayne

This line should be (Vb-0.7)/0.5k=(Beta+1)*((15-Vb)/1k)

Not with an emitter resistor it can't. In a standard common emitter configuration, if the circuit in question has an emitter resistor then the collector current is limited by that. Strictly speaking, this isn't an electrical engineering question, it's electronics. You might find a lot of interesting and relevent electronics discussion in one of the electronics newsgroups.

Dave

Sorry Dave. I tend to ask circuit questions in the engineering group and repair related to regular electronics newsgroups. Not that I am trying to offend anyone at all.

Thanks for the help everyone!

"Dave D" wrote in news:4274bb06$0$287$ snipped-for-privacy@news-text.dial.pipex.com:

Hello, and "strictly" speaking it is an EE question. Unless you think that the practice of EE is restricted to power generation and distribution. Most universities in the US don't think so. "Electronics" or "electronics engineering" is but a subset of EE practice. My .02 worth. Sincerely,

John Wood (Code 5550) e-mail: snipped-for-privacy@itd.nrl.navy.mil Naval Research Laboratory

Hello, all, and I should have added in my previous post that one can certainly be an electronics hobbyist or electronics technician (with appropriate training) without a university-conferred EE degree (BS, MS. PhD). Sincerely,

John Wood (Code 5550) e-mail: snipped-for-privacy@itd.nrl.navy.mil Naval Research Laboratory

I was merely trying to direct Peter to an electronic-specific newsgroup where he could find advice from people specifically trained in electronics, I didn't set out to offend anyone.

Dave

Peter, I'm sorry if I gave you the wrong impression! It simply occurred to me that an electronics group might be more suited to your question. There's nothing wrong with posting such questions here, and I certainly wasn't having a go at you, just offering friendly advice :-)

Dave

I went over the message last night and it was full of information. My problem is I'm terrible at looking at this and creating 2 loop equations with 2 unknowns.

I knew all the formulas, but it was unclear to me as to how to come up with the numbers. Even when I first looked at the two equations nothing came to me. then I sat down and said ohhh 2 equations and 2 unknowns.

Even though I came up with Vb=14.72 and Ve=14.07, Multisim for some reason was using around 0.8something volts from B to E. It's fine, you can't get exact numbers and I'm sure if I played around with the parameters I can get these numbers. It may be due to the higher Ie creating a higher voltage drop.

Thanks again!