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Vbe stuff

J

Jim Thompson

Jan 1, 1970
0
When i have some spare time, i will try just the E-B junction and use
a transistor socket wired up for the purpose.
Other than measuring the environment (21C) and letting the transistor
"soak" in it for over 1/2 hour, how do you suggest i "measure" the
transistor temperature?
A Tektronix 7D13 that measures temperature with an external
transistor agrees with other measurements of the environment
temperature; and i used the same MPSA42.

I've already remarked, but you've ignored... E-B ONLY will confuse you
even further than you already are.

Maybe you should pump gas for a living ?:)

...Jim Thompson
 
J

Jim Thompson

Jan 1, 1970
0
Jim said:
Jim Thompson wrote:


On Fri, 20 Oct 2006 08:10:41 GMT, Robert Baer



Jonathan Kirwan wrote:

[snip]


You can do a one-point calculation of Is, just as I did earlier. That
works and is simple, but it may not be enough at times. You can do
better than this by doing curve-tracing of Ic versus Vce with a range
of fixed Vbe's set up. Then take each fixed Vbe that you used and
find it on the Vce (horizontal) axis and mark them. Take a vertical
line up from there and mark its intercept with the associated Vbe
curve you traced out. Do that for each Vbe you used. That will give
you points where Vbc=0. (Not done like you did with B and C shorted.)
This allows for a more accurate estimation of Is, drawing the line
back to its intercept with the Ic axis.

Jon

Forget all of that. KISS.
I made a measurement and it did not even come close to what Mr Pease
said.
I made another measurement at a different current with the same result.
I am puzzled about that discrepancy.


Robert, Post your lash-up. You must be doing something terribly
wrong.

...Jim Thompson

Very crude; the base and collector leads were twisted together and
poked into the "sideways: hole in the banana connector which then was
cinched up; the emitter lead was treated in a similar manner to the
other banana connector of an HP5326B in DVM mode.
An adhustable HP6228B supply in series with a fairly large resistor
and current meter supplied the current to the lash-up at the banana
connector plugin holes.
When i have time, i will try with the collector open.


Don't do that, you will further confuse yourself ;-)

What is it that is still troubling you?

...Jim Thompson
The measurement i made of the MPSA452 in DCT mode at 21C was
significantly lower than what Mr Pease stated (implied as fact for
virtually all transistors).

Why do i have to repeat this so many times?

Why do you keep ignoring what others tell you, and get with the fact
that Pease is not only a confusing twit, but you are twisting it even
further.

VOLTAGE DOESN'T MEAN SHIT, ONLY DELTA!

...Jim Thompson
 
M

Michael A. Terrell

Jan 1, 1970
0
Jim said:
I've already remarked, but you've ignored... E-B ONLY will confuse you
even further than you already are.

Maybe you should pump gas for a living ?:)


Work for taco bell?


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
 
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