Kurt Mahan wrote:
> >
> > Thanks for the tip, but if you could supply a clarification...
> >
> > The TO-3 socket is on the OTHER side of the chasis. The screw holes in the
> > chases are just plain drilled holes, no special insulation, so the screw has
> > to pass through the TO-3, through the chases, and THEN into the TO-3 socket.
> > I can't imaging how the screws could NOT touch the chasis.
> >
> > How is it that where the screw passes through the chasis, that it does not
> > short out?
>
> Well, try just inserting the socket onto the chassis -- notice that if
> you insert the screw it is kept in the center of the hole -- its not
> shorting to the chassis. If you put the mica insulator on (lots of heat
> goop), put the transistor on and press everything together, you should be
> able to insert the screw and not have it shorting to the chassis.
Not to nitpick (even though that's what I do best) but two of
these replies have said to use lots of heat sink grease.
WRONG!
The object is to fill the pores in the metal and mica. Any more
grease than it takes to do that will DECREASE the heat transfer.
A very light coating is optimal. Or use elastomeric washers
(a gray rubbery washer). Ungreased elastomer will transfer
heat as well as greased mica. Greased elastomer works as
good as beryllium oxide (looks like white ceramic) without
the health hazards of beryllium oxide.
Received on Thu Mar 18 02:59:10 1999
This archive was generated by hypermail 2.1.8 : Fri Aug 01 2003 - 00:31:53 EDT