I did this way back but apparently didn't worry about it or just forgot it.
The SC/CO has a deadband of roughly 80F - that is, if your max is 460, your temp will drop to 380 before the thermostat kicks in, at least on the Sunpentown. Logically this will confuse your beans.
Did a search and find that Folks like JonR are setting their CO on max and using a variac.
Anyone know of a cheap source of variacs? (hah!)
So at ebay it looks like at least $50-$100.
It seems to me that an alternative would be a PID/SCR/tc, and since I have a Fuji lying around I may just try that. The problem with a PID is you have to push those little buttons 4 times during a roast to set the temps at the appropriate times to get your profile. (as opposed to just turning the variac knob 4 times)
Also look at Powerstats. The model 116 is pretty common. Like from 0-140V with an 8amp fuse. Mine was $54 shipped across the country. It looks old (it is) and well used but works fabulously.
Also look at Powerstats. The model 116 is pretty common. Like from 0-140V with an 8amp fuse. Mine was $54 shipped across the country. It looks old (it is) and well used but works fabulously.
Yes - a good search on ebay would be (variac,powerstat,autotransformer)
If the PID doesn't work out for me, that's definitely what I'll do - and for folks who don't want to open their Sunpentown (or whatever), that definitely sounds like the route.
kristi, I am interested in your PIDing your TO. How did it turn out? I am finding the same problem with the temp dead band. I would be interested in some sources for setting up a PID.
kristi, I am interested in your PIDing your TO. How did it turn out? I am finding the same problem with the temp dead band. I would be interested in some sources for setting up a PID.
I am very pleased with it. My wandering PID has found a home!!!
You need a PID with ramp/soak functions so any PID with that and an SSR drive will work. I got mine from Brinker controls a year ago. Click Here (cgi.ebay.com) I believe that is the same one.
It is a wierd link as it always comes up telling me that I have already committed to buy so before you actually use that link you might email Brinker and check.
My PID model is PXR3RCY1-4VOA1 unless there is a typo. It has a built in SSR driver so I just connect it to the SSR primary and use the secondary to gate the heater element in the TO. It's not exactly flat but it's a HELL of a lot better than before. You may need to play with the P, I, and D values to get what you want. I'll be happy to share mine once you get it going.
Per eodove's profile, I am currently trying: (warm up to 300F for 3-5 min or so) Pour in beans and start program: 300F for 5 min 435 for 4 min 460 for 2 min 482 until end of roast (FC or FC+)(depending on beans)(usually 1 1/2 to 2 cups beans)
I usually get 1st crack at 12-14min and 2nd crack starts at maybe 18 min.
I've done 4 or 5 roasts with this profile and I notice that they REQUIRE a rest period of 2-4 days after the roast, but seem to taste great. but I have yet to do any variation on that - waiting for eodove to blaze my trail :o)
If you have any questions on how to do it, etc, fire away!
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