[sdiy] LM394 vs. MAT02 vs. ?

[James Patchell]

Transistors are so damn cheap that if for some reason a glued together pair 
turned out not to be matched, into the garbage can they go.  I am not going 
to sweat 10 cents...

At 08:21 AM 11/5/2004 -0800, Metrophage wrote:
>Not a bad idea, but wouldn't a permanent pair be easier? If you do the
>matching well enough ahead of time there seems to be little reason why
>one would need to change these.
>
>I am guessing that two transistors which are encased in glue or epoxy
>are going to be better thermally matched than two out in the open with
>goop between them. This way they are not only (for the most part)
>thermally matched to each other, but also insulated a bit from ambient
>temperature changes.
>
>What I am considering, while I plan my next array of built-from-scratch
>stuff - is using DIP headers to make little epoxy pods which include
>the expo pair and their tempco resistor. This way the whole assembly
>sockets easily, and can be swapped out with no trouble if one is
>dissatisfied with it, or if it is damaged.
>CJ
>
>--- John Speth <johnspeth at yahoo.com> wrote:
>
> > > > > And if you want to be real cheap, try hand
> > > matching a pair of
> > > > > 2n3904's...they work fair well (you must glue
> > > them together to make them
> > > > > work)....
> > > >
> > > >How does one do this?
> >
> > I saw a good idea once (I think it was on sdiy) that
> > you can apply heat sink goop to the flat sides of the
> > transistors and then use a ty-wrap to hold them
> > together.  You get a good thermal joint that is not
> > permanant.
> >
> > JJS
> >
> >
> >
> >
> > __________________________________
> > Do you Yahoo!?
> > Check out the new Yahoo! Front Page.
> > www.yahoo.com
> >
> >
> >
>
>
>
>
>__________________________________
>Do you Yahoo!?
>Check out the new Yahoo! Front Page.
>www.yahoo.com
>

         -Jim
***************************************************************
http://www.oldcrows.net/~patchell

***************************************************************