On Monday 12 June 2006 14:17, Robert A LaBudde wrote:
> At 03:15 PM 6/12/2006, PicDude wrote:
> >But I've had difficulties soldering the thermocouple wires to the board
> >(tried
> >both stranded and solid wires, and tin/lead or silver solder).  Have not
> > been able to get any other acid solder, etc here.  So I've moved to plan
> > B -- which is to crimp the ends to regular stranded copper wire, then
> > solder the copper wires to the board.  The copper wires would be only
> > about 1/4" to 1//2" inch long, and the crimped connection will be draped
> > right over the temp sesnor.
>
> You can twist the wires together and then weld the joint electrically. You
> could also try a propane torch.

No welder over here in FL. :-(  But I'm planning to twist together, then crimp 
the joint inside a butt-splice connector.  Just looking for a small-enough 
one with the heat-shrink already over it.


> Acid solder flux is ammonium chloride. This may be available from other
> sources. Have you tried 100% silver solder?

Tried Radio Shack 63/26/2 "Silver bearing solder".  Not 100% silver.  I have 
not found 100% silver anywhere yet, but I saw silver epoxy at mouser and 
considering it -- essentially it is conductive epoxy, so I would twist the TC 
wire ends to copper wire and join with the silver epoxy.


> Ideally, all of your cold junction connections should be mounted insulated
> on a heat sink to keep them all at the same temperature.

Heatsunk together may be a problem, but the temp sensor and cold junction are 
right next to each other, and sealed within a small enclosure.  I just need 
to make sure that any potting compound does not get between those 2 and add 
thermal insulation.

Cheers,
-Neil.

>
> ================================================================
> Robert A. LaBudde, PhD, PAS, Dpl. ACAFS  e-mail: ral@lcfltd.com
> Least Cost Formulations, Ltd.            URL: http://lcfltd.com/
> 824 Timberlake Drive                     Tel: 757-467-0954
> Virginia Beach, VA 23464-3239            Fax: 757-467-2947
>
> "Vere scire est per causas scire"
> ================================================================
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist