Homebrew PCBs

Hi DJ Delorie. 

Thanks for the feedback. I am going to do one myself for a laminator. Those max chips are just cool. 

Trev


--- In Homebrew_PCBs@yahoogroups.com, DJ Delorie <dj@...> wrote:
>
> 
> "trevwhite74" <trevor.white100@...> writes:
> > DJ Delorie, you mentioned before you did your own temperature
> > controller for your laminator. Did you do anything special to
> > control the temperature? Did you use any control loop or just on/off
> > monitor of the temperature.
> 
> The thermocouple chip I used returns four samples per second, so I
> just did a plain "less than=on/greater than=off" test, once per 0.25
> seconds.  It keeps the heater within about 10F with a 10-30 second
> cycle, which is fine for me.  Recall I'm sensing the heater temp, not
> the roller temp.
> 
> I did put in a 60Hz sensor with appropriate timed delays to syncronize
> with the zero crossings.  At the moment, I just use it to push the new
> setting out, but I put it in in case I wanted to play with PID control
> later.
>