Okay Folks,
This is my first answer to additional OBS automation.
(http://img248.imageshack.us/img248/875/img0388lf.th.jpg) (http://img248.imageshack.us/i/img0388lf.jpg/)
When the food IT reaches setpoint, cabinet heater setpoint switches to hold temp setpoint.
In this thread http://forum.bradleysmoker.com/index.php?topic=7213.0 (http://forum.bradleysmoker.com/index.php?topic=7213.0) FLBentRider asks about a PID that could also monitor the food temp.
Rather than roll my own. I opted to go the off the shelf route. Not a two input PID per se, but three PIDs. One for cook temp, one for hold temp, and one for food temp.
I got most of my pieces in, so yesterday (2009-10-24), I started putting together my prototype.
I don't know how to make it work with just two probes. So I have three. Two for cabinet temp. And one for food temp.
Presently one mounted the same height as the stock temp probe on the door. And one under the lowest shelf.
Each feeding a separate PID.
current drawing:
(http://img337.imageshack.us/img337/5259/pidplusholdandalarm2.th.png) (http://img337.imageshack.us/i/pidplusholdandalarm2.png/)(http://img26.imageshack.us/img26/8439/img0386z.th.jpg) (http://img26.imageshack.us/i/img0386z.jpg/)
All PIDs purchased from Auber.
2 http://auberins.com/index.php?main_page=product_info&products_id=3 (http://auberins.com/index.php?main_page=product_info&products_id=3)
1 http://www.auberins.com/index.php?main_page=product_info&cPath=1&products_id=1&zenid=e86f5c0f31e1ef6a1b8c0f83f66ca438 (http://www.auberins.com/index.php?main_page=product_info&cPath=1&products_id=1&zenid=e86f5c0f31e1ef6a1b8c0f83f66ca438)
Joe
Interesting project. What temperature do you use for a hold point?
Habanero Smoker,
I'm using 140. (It's a regular PID, so the setpoint is easily changeable.)
Joe
PS.
It needs remote indication of some sort. Apart from that and a more polished case. I very pleased thus far.
It just needs a little stain and shellac, then it will remind me of a wooden dashboard. :)
Okay
Let me see if I get this right. Probe 1 Monitors the cab temp.
Probe 2 Tells current temp of meat
Probe 3 Would adjust the cabinet temp to maintain the meat at your max temp
Is that right,........ I'm kinda slow.
CRG,
Two of the probes monitor cab temp. Setpoints for cook and hold .
One for food temp.
From right to left on what I've put together; Cook setpoint, Hold setpoint, and Food done setpoint.
It was working on a BC chicken when I took this photo.
(http://img248.imageshack.us/img248/875/img0388lf.th.jpg) (http://img248.imageshack.us/i/img0388lf.jpg/)
(My two cab probed aren't at the same height.)
'Hope this helps,
Joe
ok, thanks