[lunkhead]

I finally grew tired of fighting the defrost cycle on my Danby DKC645 so I found a Johnson Controls model A19ABC-24C temp controller on line for 32.50 + 5.00 shipping and installed it a couple days ago. Been testing it the last couple of days with a 2.5 gal bucket of water and is working great. have it set for 35 deg on the dial and it kicks the compressor on at 39 deg and off at 34 deg, a 5 deg diff, which is what I have it set for. Water temp in the bucket is 36.5 deg, right smack dab in the middle.

I also decided to see if I could calibrate the temp sensor reading on this thing, it's there, might as well see if it can be made useful. I cut the 33k resistor out and dunked the sensor into an ice water bath with my calibrated round dial thermometer and waited about 15 minutes for the readings to stabilize. The round dial read 32 deg (good, it's still accurate) and the Danby display read 30 deg. Humm, might be these things just won't get cold enough. From my previous research with the 33k mod it would appear I need parallel resistance but 33k is too low, raised the reading to 35 deg, I only need to come up to 32. I started out with a 220k and the reading came up to 32deg. (IMPORTANT NOTE: the reading does not change instantly, takes about 5 minutes) I tried several values from 82k to 560k to try and find the center of the reading. On my unit (don't know if yours will act the same) anything below 100k or anything above 390k would move it above or below 32deg on the display. Measuring the voltage across the sensor, with 100k volts was 2.79vdc, with 390k volts was 2.84vdc. It looks like 2.81vdc is pretty close to center at 32 deg. The 220k that I started with gave me 2.83vdc, a little high. It looks like a 145k would do the job, but that's an odd value I don't have lying around, but I do have lots of 150k resistors, so I used that. 2.81vdc, right where it needs to be. (Please note that this takes some time to do as the readings on the danby temp display don't change instantly, keep the ice bath up and I had my round dial in it the whole time to insure 32 deg temp) So how is it at a higher temp?? I grabbed the 2.5 gal bucket of water, which by now should have warmed up a little, and in went the sensor and round dial. Waited about 15 minutes and stirred the bucket a few times, both readings were 43 degrees!!! Glad to see that. Just for fun I put an old red mercury looking thermometer that I use to keep track of the basement temp in the bucket and it came in at just a tad under the 44 line. So I put it into the ice bath and it read about 32.5 deg. It looks like the Danby display temp is now pretty accurate, at least from 32 to 43 degrees (BEER TEMP) and maybe/hopefully a few degrees below and above 32 - 43.

Other thoughts, using the 150k instead of the 33k will lower the danby temp 2 deg instead of 6 deg. Perhaps using 150k and moving the sensor to the top front of the danby (suggested in previous posts) will give better temp results, if anyone would like to try, but there is still the dreaded (at least to me) defrost cycle. The 150k would just go in place of the 33k, same hook up, in parallel.