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jaysouth
08-20-2014, 09:21 PM
My hand me down toaster oven died. I bought a Black and Decker from WalMart for $29.95.

Using a K type probe on a digital thermometer, the oven temp would range from 300 to 425 when set of 375.

I took that one back.

Next was a black and decker for $24.95. The temp range on the dial was max of 450. However with the K probe, it would not get over 325, whatever the setting. I then hooked up a PID controller set on 400. Temp ranges displayed on the PID were from 330 to 395.

This one is going back tomorrow.

Any recommendations on a oven that works for a decent price?

Beagle333
08-20-2014, 10:26 PM
Mine worked just fine with the PID. How did you have it hooked up?
You gotta go around the thermostat on the little oven. If you wire it straight, the rods will heat up until the PID shuts it down or it goes into nuclear meltdown. :twisted:
http://i613.photobucket.com/albums/tt214/shutupandjump/probe1_zps48578b45.jpg http://i613.photobucket.com/albums/tt214/shutupandjump/probe2_zpsff8bd050.jpg
I have a convection oven hooked to the PID now, but the old B&D stayed within 5° of set temp.

jaysouth
08-20-2014, 10:42 PM
Hmmm............Never thought about a thermostat on the oven. I just plugged the oven into the PID and inserted a flexible K probe between the door and frame to read temperature. Then I set the oven's dial on 450.

Where is the thermostat and how does one bypass it?

Thanks

el34
08-20-2014, 10:47 PM
Were they convection? Mine is from Walmart, the temp knob is accurate and holds + / - 20 deg according to the thermometer I tested it with. It's a 2-level B&D model TO1675W-

http://www.walmart.com/ip/Black-Decker-Convection-Toaster-Oven/15806194

bangerjim
08-20-2014, 11:31 PM
I have a WelBilt convection oven that cost ~$100 and it maintains 400F on the dial within 10 degrees. And NO stinking PID controller. Controllers.....we don't need no stinking controllers. :guntootsmiley:

If you want to use a controller you must bypass the bimetal thermostat inside/behind the knob on the front of the oven......pretty much eliminates taking it back!!!!!!! You can't just plug it into your pot controller. And if it is a convection oven you can/will mess up the fan! You have to wire that in so it is on all the time. In other words ANOTHER cord to plug into the mains outlet.

banger

el34
08-21-2014, 12:59 AM
And NO stinking PID controller. Controllers.....we don't need no stinking controllers. :guntootsmiley:

banger

Hmmm, that might be an interesting subject for a survey.

Beagle333
08-21-2014, 05:21 AM
Controllers.....we don't need no stinking controllers.




https://video.search.yahoo.com/video/play;_ylt=A2KLqICgufVTkjQAliH7w8QF;_ylu=X3oDMTB2ZX A5OGc1BHNlYwNzcgRzbGsDdmlkBHZ0aWQDVjE3MgRncG9zAzE-?p=badges%3F&vid=f75e8b32285a2a03c1faa4b35419261f&l=00%3A46&turl=http%3A%2F%2Fts2.mm.bing.net%2Fth%3Fid%3DVN.6 07992203425350165%26pid%3D15.1&rurl=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3Dns dZKCh6RsU&tit=We+Dont+Need+No+Stinkin+%3Cb%3EBadges%3C%2Fb%3 E%21&c=0&sigr=11ao2qupa&sigt=116hisoc9&age=162822398451&fr=yfp-t-418&tt=b

bangerjim
08-21-2014, 02:10 PM
A classic clip!


banger

bangerjim
08-21-2014, 02:26 PM
Hmmm, that might be an interesting subject for a survey.


Truth be know, a SINGLE t/c just shoved in the side of an oven only measures the temp at ONE spot in the oven. Not what we really want. Same thing with the bi metal thermostat in conventional style toaster ovens. The air in a convection style oven is constantly moving and stirred up to create an AVERAGE uniform temp profile throughout (as best we can do in a cheap consumer electronics oven).

To use PID-based control effectively without convection, you would need at least 4 t/c hooked up in an oven profile configuration, average those electronically, and derive the control signal off that resultant value. Something beyond what we need or do!

A single t/c can easily monitor the temp of a liquid media like lead relatively accurately and that is why many find PID-based controllers useful in their casting pots. I personally do not. And I sell them.

Not so much in an oven.

Just the physics behind real temp control......not just here say from me.

bangerjim