--- In
Homebrew_PCBs@yahoogroups.com, "John Craddock"
<John.Craddock@...> wrote:
>
> Or maybe: -
> http://groups.yahoo.com/group/E-Z_Bake/
>
> This thread is related to Stefan's toaster oven mods to be able to
> bake direct inkjet pcbs; and perhaps to double as a reflow oven
> (my objective).
Yes, but it is squarely into electronic design now. We've been over
this before, if you try and say that anything remotely related to
making PCBs is on topic, soon we're discussing brake linings and
baseball scores because you might drive your car to pick up hydrogen
peroxide and listen to the game on the way.
There have already been past discussions and links to PID and such on
the Electronics_101 list. Absolutely integral to a project such as this.
> BTW, I bought the MAX6675 (A$8.64), much happier now,
> thanks to help from members of this list. BTW2 a diode
> compensator requires a isothermal block at the cold junction;
> the MAX6675 gets away without this.
I just ordered a couple of samples of both the MAX6675 and DS2761.
Although the DS2761 is a LiIon battery monitor IC, Maxim has an app
note on how to use it as a thermocouple chip. The thermocouple
connects to the battery voltage monitor input, and the chip's built-in
temp monitors cold junction temp. However, an external computer must
do all the processing.
No, the MAX6675 does -not- remove the need for some kind of isothermal
block. The thermocouple wires -must- be soldered/connected right at
the IC, or the connections will be at a different temp than the sensor
inside the IC.
Having a silicon diode in intimate physical contact with the
thermocouple to PCB connections is not difficult.
Steve Greenfield