SC/TO

[peter]

A simple toggle switch, rated for 10A works well too.  Drill a hole, mount the switch, and splice into the wire from where the cord connects to the thermostat.

BW, do you ever find the two thermostats acting independently would contradict what you're trying to do with the profile?  I am thinking there may be times when you adjust the heat down on the TO to maintain temps, but the SC wants to turn on and add heat.  Has that ever been an issue?

A long time ago, I measured the temps that the SC could attain, but forgot what they were.  But if the SC can only produce say, 375F, then once the roast gets past that point the SC thermostat may never get cool enough to turn back on.  Does that make sense?

[headchange4u]

I read on a couple of sites that the SC reach about 320*.

[ButtWhiskers]

That certainly makes sense - I'm positive the SC gets much hotter than 320?F, though.  Most popcorn won't pop below about 340?, and at that temperature it takes a long time to transfer sufficient heat.  Most poppers work at 400? to 460?, which is the ideal temperature range to pop popcorn (and coincidentally/luckily also the upper end of the range of where we want to be when roasting coffee!). 

A couple of thoughts:

-the more a turbocrazy is loaded, the larger the heatsink there is for the kinetic energy coming out of both devices, and usually there is good ventilation as well.  This gives an entirely different cross-sectional heat profile than an empty stircrazy with a (basically) sealed plastic dome.

-heat rises, but the thermocouple in an SC is lower than the heat zone.  This could mean that the SC thermostat is set to switch at 320?, but the temperature above is a lot higher.

-when I was running an old SC with big cracks in the casing, I could watch the coils cycle on and off.  They were almost always on/glowing until the second crack was reached (~445?F bean temperature).  I even thought about using this phenomenon as a timer at one point, but it got too complicated.

[peter]

Maybe it would be good to remove a portion of the SC element so that it could only get so hot, and then take the thermostat out of the loop.

[kuban111]

When I'm on a serious roasting binge, I run two TurboCrazies continuously producing 10# an hour.

I'm your student  OB1  :notworthy:

Michael

[headchange4u]

From looking inside several, I don't see much difference in how they're made.  The GG unit I use has 1450W and is a tad quicker to respond than my 1200W Decosonic, but not as much as 20% difference is wattage would suggest.  I think most of the older ovens are nothing more than relabeled something-or-others.  <snip>

I know that the GG come in different wattages. I was looking at a Decosonic unit the other day and it looks exactly like the GG 1200w unit except for the labels.

[peter]

I use a Decosonic 1200w unit, and seems to keep up fairly well w/ the GG 1400W.


As an aside, for you electronic smarties out there...  what does it tell you if the cord from the TO is getting warm, right where it plugs into my 12ga. extension cord?  Is it because the juice is being forced from a larger gauge wire into a smaller one?

[grinderz]

How hot are we talking? A little warm or really hot? A 100ft 12 gauge cord would be rated at 1800 watts, so your extension cord probably isn't the problem. Have you tried plugging it into an outlet directly to see if it still gets hot?

One other thing comes to mind. If a cord has been flexed a lot, the copper wire can become work hardened and brittle and eventually the individual strands of wire start to break. That decreases the current carrying ability of the cord and you start to get more resistance which produces more heat.

[peter]

How hot are we talking? A little warm or really hot? A 100ft 12 gauge cord would be rated at 1800 watts, so your extension cord probably isn't the problem. Have you tried plugging it into an outlet directly to see if it still gets hot?

One other thing comes to mind. If a cord has been flexed a lot, the copper wire can become work hardened and brittle and eventually the individual strands of wire start to break. That decreases the current carrying ability of the cord and you start to get more resistance which produces more heat.

It's hard to quantify warm (since I lent my infra-red thermometer to Pyment  ), but it's definitely warm-warm, but not hot.  I could run that test directly into an outlet, but that would mean having it run for an hour for no apparent reason; not roasting.

The 12ga. cords are only 50', so they're not the issue.  And it's not that the juice is stepping down into a smaller cord?

The age of the cords (both TO's are of the same vintage, and both cords get warm) is something to think about.  I would think that the cords flex fairly equally along their entire length, so it seems odd that if this was the culprit they would only be getting warm at the plug.