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[DPRG] emitter/collector/base

Subject: [DPRG] emitter/collector/base
From: Kipton Moravec kip at kdream.com
Date: Tue Jul 24 22:45:51 CDT 2001

Unfortunately it is not so simple.

If you have to have an input, output, ground, you are probably talking

Transistors can be used as part of a regulator.  In fact I use a pair in a
darlington arrangement for a high voltage +155 (and -155) first stage of a
two stage regulator.

Looking at your last few posts, I am guessing that you are looking at a
regulator for your robot.  A transistor can be used as a regulator if it has
the proper circuitry around it.  But it is easier to use an off the shelf
regulator.  For 5V output the LM7805 is the normal one people use.  It can
go as high as 1.5A in the TO-220 package, but you have to heat sink it well
if you pull that much current.

A switching power supply is more efficient, but costs more.  They can be
found in a package with the same pinouts as a LM7805 but with a small
switcher board.

Get a copy of the Mouser catalog http://www.mouser.com and the Digikey
catalog http://www.digikey.com.  I personally like Mouser because they ship
out of Mansfield, TX and I get the stuff the next day.  Anyway you can learn
a lot from looking at the catalogs.

Also look up the parts you are interested in on the company website.  They
all have datasheets of the part to let you know how to use it.  Another
valuable source of information is the Application Notes -- they often give
complete circuit examples that do what you need.  For power supplies, the
National website http://www.national.com has a lit of good information on
switching power supplies, including a program to help you design a switcher
to your specifications.  You had mentioned a 5 to 18V input and 5V output.
You forgot to mention how much current at 5V, but the National program will
design it for you. (Provide a schematic and parts list) It is support for
the "simple switcher" product line.

----- Original Message -----
>From: "montgomery f. tidwell" <mtidwell at practicalmatters.com>
To: "'DPRGlist'" <DPRGlist at dprg.org>
Sent: Tuesday, July 24, 2001 9:51 PM
Subject: [DPRG] emitter/collector/base

> Howdy,
> can someone explain (in newbie terms) what these three mean?
> (in relationship to an a1015/nte290a/power regulator??)
> i assume that one is to ground, one is input, and the other is
> output. but which is which?
>                              \\//_
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