Re: Tron: parts question

On Mon, 29 May 2000 17:21:25 -0700 (PDT), you wrote:

> I'm looking at my board, and my schem trying to figure out what to
>replace, what not. Two items that look like good candidates are the
>"chips" at U3 & 4. The spec lists them as LM3900 and 4N28
>respectively. The problem I am having, as I wander around RS.com (I
>know, but I'm just starting out in repairs) is that I don't know what
>these are called, so as to find them in the appropriate listing on the

        LM3900 is a Quad Comparator, and 4N28 is an Optoisolator. Radio Shack
will probably have the LM3900, but it's doubtful that you'll find the 4N28
from them (at least not as an in-store stock item; they might be able to
special-order it for you).

        However, Digi-Key (www.digikey.com) _does_ have both of these parts.
The 4N28 (Digi-Key's part # is 4N28QT-ND) is $0.30 each, and the LM3900
(Digi-Key # LM3900N-ND) is $1.23 each. The only downside to Digi-Key is
that you either have to order a minimum of $25 worth of stuff, or they zap
you with a $5 "handling charge"...
-----------------------------------------------------------------------------
When they took the fourth amendment, I said nothing because I didn't deal drugs.
When they took the sixth amendment, I said nothing because I hadn't committed a crime.
When they took the second amendment, I said nothing because I didn't own a gun.
Now they've taken the first amendment, and I can't say anything about it.
-----------------------------------------------------------------------------
solarfox@DON'TMESSWITHtexas.net (Gary Akins jr.)
http://lonestar.texas.net/~solarfox
-----------------------------------------------------------------------------
---------------------------------------------------------------------------
** To UNSUBSCRIBE from rasterlist, send a message with "UNSUBSCRIBE" in the
** message body to rasterlist-request@synthcom.com. Please direct other
** questions, comments, or problems to neil@synthcom.com.
Received on Mon May 29 18:55:50 2000