2N3055 saturated

123

01:14:15

Reading off the DS from ST Micro, the left model of the 2N3055 is fairly close to the saturation specs. Ic 4A, Ib 400 at 1.8V gives Vce 1V.

The same configuration on the right model doesn't match at all though. Oh well. But at least now you can get a better idea of how it'll work in EC.

For better simulations you need LTspice.   Or just build it and see.  That's the best way :) 

published 11 years ago

rbrtkurtz

11 years ago

I've been having the same issue with diodes. You can match portions of the curve, but not the entire thing. You know, say at 10mA voltage be X, then at 20mA voltage should be Y. I set it up for 10mA, get everything right, then when I push it up to 20mA, voltage is not Y. Then there's transistors... I was working with a while back, and beta changed quite a bit depending on the amount of voltage on the base. We don't get that option, beta is one fixed setting.

faceblast

11 years ago

gain should be a constant on any transistor; it's all the other malarkey that shifts around

Sine_eyed

11 years ago

Right on man- this is helpful thanks. And I agree with you on working tests- data sheets are helpful of course, but only to a point. Simulators are awesome for a bunch of reasons, but they're far from 100% realistic in most cases. Better of just to put some damn voltage on the thing, take some readings and go from there!..

rbrtkurtz

11 years ago

https://www.dropbox.com/s/uqzj00hta0dwucd/Screenshot_2014-06-02-18-24-12.png https://www.dropbox.com/s/6sjry3pmpf7hswj/Screenshot_2014-06-02-18-25-20.png. Sorry man, DC gain isn't a constant.

faceblast

11 years ago

I agree kurtz; everything I read and everyone I ask says Gain is Constant, but the DS shows a gain curve! I still don't get it.

joefranklin

11 years ago

Cool.. what's LT spice? Sorry, I'm a big 'ol dumby. I'm trying to learn.

faceblast

10 years ago

Another electronic circuit simulator with much heavier features

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