EEVblog #101 - Hacking your own Peltier LAB Thermal Chamber

Buy the same model here:
Dave turns a low cost reptile egg incubator into a decent 2degC to 60degC lab thermal chamber.
Throw in a Rigol oscilloscope, an Arduino, and a few multimeters for good measure.

The model used is the HERP Nursery II, also known as the BCR-25 Wine/Beer chiller and Pie Warmer.

[DreitTheDarkDragon]

14:14
- Can we taste some good wine?
- No, but I have whole bunch of multimeters in my fridge!

[jeromekerngarcia]

Hey Dave, I only found EEVblog a couple months ago, and I'm glad I did. I think you're doing a great job bringing a fresh approach to passing along EE/ET info. As a long-time hobbyist then a working EE I must say :"thanks" for DaveCAD - I've been using it for *years* and never knew from whence it came. I like your enthusiasm for the field, I hope it's infectious. These are great days to be involved in electronics - I thought the hobby was dying out, and it's really nice to see the Maker come up.

[MrOpenGL]

I bought a similar minifridge and soon got tired of it because it didn't cool much. So I sold it and bought a compressor based minifridge. I redid the insulation work (added 2, 5 times more insulation) and now with the compressor it can cool down to -25°C if the condenser is sufficiently ventilated.
I also put a 300W element in it which can heat the thing up to 70°C (with the compressor obviously off) and then put an electronic thermostat for control. And it works wonders!

[EEVblog]

@Steaphany I'll have to investigate and actually try it at 120V also. Although if it was capable of a wide input range, they would have marketed it as such I suspect.

[EEVblog]

@JonDeth I didn't want to craft my own. I saw this unit and wondered if it was a suitable chamber for electronics testing use as-is, and it is. Something others can buy off-the-shelf and use themselves.

[EEVblog]

@asus3571 Components can be affected by as little as a 1degC temperature change. Depends entirely on what spec and part you are talking about.

[EEVblog]

@ubuntututorials Perhaps. More investigation required on this front. But it's all dependent upon ambient temperature, and some times the devices did not even reach it's 2degC or 60degC limit due to the ambient.

[EEVblog]

@JonDeth Yes, I'm just hacking a mini fridge, no big deal. I never made it out to more than that. Some people might like an small thermal chamber like this for their lab, and they have better and more interesting things to do with their time than make their own thermal chamber from scratch. In this case I've shown such a chamber can work well for electronics stuff.
I'm not making out I've done or discovered something amazing here, just sharing with people.

[RobertWCrouch]

Not too shabby for a reasonably priced mini-fridge/incubator! I'd suggest replacing the sealing rag with what my company generally uses on our older Thermotron 2800s: cut pool noodles. We test from -40c to +60c with no major sealing issues. Sticking some desiccant in there would be a good idea as well (and even a cheaply dollar store humidity meter). Nice work Dave!

[EEVblog]

@Steaphany Correct, easy to add whatever supply you want.

[EEVblog]

@TrueBlueAustralian Yikes. How long is a piece of string. There is a thread in the eevblog forum.

[ocayaro]

Dave, you should talk about moisture condensation when you drop the temperature. There should be some kind of dessicating agent inside. That way if failure occurs then at least you do not account for it by moisture.

[MrYendor]

I have been pushing the thermoelectric cooler to friends that did not know they exist,   at first when I told them they said,   ha  what a load, there is no such thing. solid state thermoelectric cooling bla .  it was worth it , just to hear there reaction   I been plugging them for a few years now,    just love the reaction of so called smart people .

[elvinhaak]

@eevblog - I think you can get a decent (second hand) mini-fridge like in use in hotels (bars), put a 200-300W heater-element in it and a thermo-sensor and you can do faster and more cooling and heating for a pretty low price, also going from a lower or higher temperature. It might be a bit harder to do the switching for acurate temperatures - or combine the two maybe?

[fredsun]

Thank you for the tear down showing the innards of these boxes.

[Steaphany]

Dave,

Is there any readable spec's on the incubator's switching power supply ? For your fans outside of Australia, they may be able to use it stock, just by replacing the power cable to suite their locale especially if the switcher has a wide input operating range of 90 - 260VAC 50/60 Hz as many switchers do.

[gooseknack]

Not bad! For increased performance, one could always add a second peltier. I've seen quite a few thermal coolers/warmers at the local recycling centre for around 5 bucks. Time to grab a couple me thinks!

[RPBCACUEAIIBH]

For the betterment of this chamber, I would try to add some freez'pack units that helps it to cool down rapidly, assuming that you have enough space for it inside. Heating is pretty simple to solve by drilling 2 other holes for an aditional hot air gun entrance, and exit. or just don't seal the hole you drilled while testing at high temp. Note that the hot air gun can be too hot for the foam at the entrance!!! You may also need to reprogram the microcontroller to get below 0 or over 60 grade C.

[yogipg]

in the USA we call them environmental test chambers because ours also cool. a thermal oven would be useless for me, I can get a space heater if I want to heat something. cooling is the tricky part.

[kjetilv]

Nice work, but what do you do when you need to test electronics at a normal temperature span? Normal home freezers rarely go below -17C, and that's still quite warm compared to what for example cellphones or other equipment that's used outdoor need to cope with.