Homebrew PCBs

> <John.Craddock@...> wrote:
> >
> > Hi Philip,
> > Yes, I read the article and have been doing some research of
> thermocouple interfacing. ...

why so much complication?

hardware is dead simple using a 1-wire interface from Dallas-Maxim.
thermocouple feeds directly into an ADC (DS2761) that directly digitizes with a
resolution of 15uV, measures digitally its own temperature and connects to a uP
via one pin (and ground). also has a 2-5V ADC that can be fed directly from a
pot (ie, setpoint).

so, all is needed is this chip 
( http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3468 ) plus a microP (I use
Atmel Tiny), plus an opto-triac/triac pair or a solid state relay and a few
passives, switches and a pot with a large knob.

the process is all digital and the micro has the chance (responsibility) to
implement whatever algorithm fits (from on-off to self adjusting) plus any
bells and whistles (LCD display, serial logging, profile, etc).
BTW, it DOES fit on a 1" x 2" board (exclusive of power and relay).  

I kept following this discussion in the hope somebody would come up with a two
chip reasonable analog solution, but no, no such... (at least yet)





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