DIY Thermoelectric Peltier Refrigeration

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Nightjar,
I cant tell from the eBay description, are you able to separately set the on & off temp?
For instance, turn on at 20 deg and off at 15deg.
I imagine control over the hysteresis would be important for longevity of fans etc as well as perhaps being a little more efficient with the power usage.
 
bicter said:
Nightjar,
I cant tell from the eBay description, are you able to separately set the on & off temp?
For instance, turn on at 20 deg and off at 15deg.
I imagine control over the hysteresis would be important for longevity of fans etc as well as perhaps being a little more efficient with the power usage.
Click to expand...

Bicter,
On the thermostat shown in above pic you can "set" activation temperature but not the cutout temperature.
The readout on the pic is the ambient temp (difficult to read) 23.8C. You probably notices the Engel ambient temp reads 25, I was fiddling remember so they don't match.
For the test I set the activation at 22C so the Peltier is running, when the ambient drops to 20C it will automatically cut out. The thermostat is designed this way (2C cut out lag) so what ever device you are controlling doesn't cut in & out if the ambient temperature hovers around your set point.
No doubt there are thermostats that you can set upper & lower temps. In this instance working with the ambient temperature suffices.

CTX, Totally agree, very addictive. Years ago knocked up a random number picker 1 - 45 using led's and electronics, it worked but never gave me the winning lotto numbers. :lol:
 
Nightjar said:
bicter said:
Nightjar,
I cant tell from the eBay description, are you able to separately set the on & off temp?
For instance, turn on at 20 deg and off at 15deg.
I imagine control over the hysteresis would be important for longevity of fans etc as well as perhaps being a little more efficient with the power usage.
Click to expand...

Bicter,
On the thermostat shown in above pic you can "set" activation temperature but not the cutout temperature.
The readout on the pic is the ambient temp (difficult to read) 23.8C. You probably notices the Engel ambient temp reads 25, I was fiddling remember so they don't match.
For the test I set the activation at 22C so the Peltier is running, when the ambient drops to 20C it will automatically cut out. The thermostat is designed this way (2C cut out lag) so what ever device you are controlling doesn't cut in & out if the ambient temperature hovers around your set point.
No doubt there are thermostats that you can set upper & lower temps. In this instance working with the ambient temperature suffices.

CTX, Totally agree, very addictive. Years ago knocked up a random number picker 1 - 45 using led's and electronics, it worked but never gave me the winning lotto numbers. :lol:
Click to expand...

this is a very interesting thread, & sure to provide some great ideas for anyone interested in tinkering.
Ive been very busy lately, but have a couple of bits n pieces & when I get time to make something up I will post up my results too.
One of the bits I do have is a thermostat module with upper & lower settings.
 
Have pulled a lot of peltier modules off old car cooler systems, but not had much of a go at running them yet, except to generate small amount of power. Very interesting though, love them
 
i played some more today

1571820323_p1120979.jpg


new pump , knocked 1.2 amp off the draw :cool:

took the water to 40deg and gave my puppy a bath with the 8lts produced , he loved every minuter of it :perfect: then went and rolled in the dirt the little **** :(
 
Ded Driver said:
just partly answered my own question by having a quick search.
12V DC 10W Brushless Solar High Temperature Water Pump 8L/min. $18.70 free postage from Hong Kong
10W equates to 0.8A @12.5V .... seems light, but I assume that is no load.
https://www.ebay.com.au/itm/12V-DC-...a=0&pg=2386202&_trksid=p2386202.c100677.m4598
What pump flow rate are you using ctx?
Click to expand...

Or if you're only using it for experimentation, one of these cheaper https://www.ebay.com.au/itm/Submers...m2ced21209e:g:nlgAAOSwt0pc6SSu&frcectupt=true may do the job, don't trust the spec though as its rated suspiciously high at 100Deg C whereas your more robust unit is rated to 55 Deg C.
I've been using this type on a couple of solar fountains for a couple of years and they work fine. They generally only last about a year but that's pumping dirty pond water with a filter that gets blocked up regularly.
 
yeah Limpalot, the pic I posted is just an example. It wouldnt be hard to remove the fans, build the whole thing into a box, & fit 1 or more fans on the end of the box so to blow air though it. Would probably work ok for a small volume, like inside a car or caravan. Food For Thought!
like this one with 1 fan - axial air flow
https://www.ebay.com.au/itm/Semicon...628984?hash=item3d7945e5b8:g:Q7QAAOSwOVlb4mNO
Nightjar, this could even present a feasible option for a couple of fridges, using ducting to blow air from the unit into 1 or more fridges, &/or a space that needs cool air (like under my false floor)
 
Nightjar said:
ctxkid said:
a couple of hours made 510Wh :power: :perfect: :cool: using 2x 100watt folding mats
Click to expand...

CTX, Can you explain a little more what you are doing here, I'm lost? Does it refer to what you put back into your battery while running your peltier set up?
Click to expand...

i am exploring ways of using/storing what would be wasted solar energy :idea:

the hot water is something that could be run on the move to burn unused current from a dc to dc :Y: or in this case ya solar that is at camp , the battery is charged, so to use the residual current make hot or cold water , hot for washing and cold to drink :cool:

or in a home super efficient solar station that can be used to cut utility bills (much bigger peltier :cool: ):perfect:

and best of all it has been keeping my mind occupied :)
 

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