richard@karlquist.com said: > I thought I would check the brain trust here to see if anyone has seen a > hobbyist grade temperature testing chamber or kit or homebrew design. I > have some crystals, oscillators, and other electronics I would like to > characterize over temperature. I know this reflector has discussed homebrew > stabilization ovens; however, they have tended to have very long time > constants (which makes sense for that application). I need to be able to > change temperature in a reasonable amount of time, and I don't need extreme > stability. Looking for any ideas, maybe in the "maker" spirit. I think the > size I need would be perhaps 1/2 the size of a shoebox. What temperature range do you have in mind? You can probably get close to freezing using ice. If you want to go below that, you probably need dry ice. My straw man would be a box with two sets of fan+ducting blowing over a metal back with a micro running the fans: one for hot, the other for cold. As Gary suggested, a (small) fan inside the box will speed things up. --------- Many years ago (pre ebay), my boss picked up a used refrigerator sized unit. The top half was the chamber with lots of insulation and lots of air blowing around. The bottom half was the refrigeration. It was way overkill for your needs, but if you have the space and power and you can find something like that you might find other uses for it. We only used it a few times. It was way overkill and noisy. I poked "temperature test chamber" into ebay. There were lots of expensive units. I didn't see anything cheap enough to be interesting and I didn't consider shipping. -- These are my opinions. I hate spam.