Cooler/Generator with Thermoelectric Device

I used to work in two way radio communications in the logging industry. Most work was done in the back woods in the mountains where direct long range radio connections impossible with VHF due to the mountainous terrain. The way around this was mountain top repeaters often powered by "thermal generators" which were just a large number of junctions of dissimilar metals held in a flame where the heated junctions produced an output voltage. As with the Peltier modules they didn't produce either much voltage or current but with no moving parts and no dependence on sunshine they produced the power needed to run the repeaters with no maintenance other than an annual replenishment of propane.

Hi Mehdi.

Nice vid but at 13.25 you said that increasing the current through the modules won’t cool more because the fan couldn’t remove enough heat from the hot side. The amount of heat that can be absorbed due to Peltier effect from the cool face is dQ=P*i (P is a coefficient, i is current). The amount of heat generated due to Joule heating is dQ = R*i^2. Assuming that half of that heat reaches the hot face and half the cold one, the net amount of heat that can be absorbed from the cold side is (P*i – 0.5*R*i^2), that is a parabola. Its maximum is on the vertex i = 2P/R that normally is the nominal value from the module's manufacturer. Increasing the current over that value will result in a lower “cooling effect”. Increasing further the current above the “zero of the parabola equation” will produce heat on both sides of the module. :)

ooo looking forward to watching this as i await my TEG-powered watch (i won't advertise for them here, but will mention it is a crowdfunded thing due to ship Real Soon Now and i'm excited to see it in action)

The thermoelectric Device was also so mind blowing to me, thanks now i understand it more.... Please think of us when giving away 3d printer......

Very funny. Our wife-units come from the same cold-feet warm-heart shelf. Thermodynamics was pretty exciting stuff in school... if one could handle differential equations. I could not. But I did learn to keep the water away from the electrical stuff. Stay safe!

Craig Larson

Hi Medhi! Why not put two fans spinning in the same direction, perpendicular to the plane where are the devices, on opposite sides of the "cube"? In this way you could achieve a better airflow, with air coming from one side and leaving on the other. Also, maybe you could use fans requiring even lower voltages and using less energy . Great video as always!

That's better, although solar panel could provide more power

ElectroBOOM [Mehdi Sadaghdar]

How about putting the system buildt in a river, exposed to the sun ? This would heat up the upper side and cool down the lower one with only "green" input. Not sure if the voltage/current obtained would be sufficient to power any outdoor appliance though...

As an electrical engineer you sure kept your fingers away from the saw blade, but bare wires you have to touch…

Thomas Eriksen

So these could be used to increase efficiency of other devices by reclaiming energy converted to heat.

New to this channel and I love it! And I learned something….

@Travis - The TE explanation of how a Peltier works is very clear and helpful. Thanks!

Allen Cobb

20% off a free subscription? 🤔 🤔

Jonas Otter

Another channel I follow, "Tech Ingredients," has done some good treatments on TECs. They've done five videos in relatively recent history spanning a functional mini-fridge build, a functional mini-freezer build, and testing the limits of how cold they could drive the cold side. You inquired about the principle of operation; here's their relatively simple explanation from the mini-fridge build episode (link goes to the time of roughly where the relevant part of the description starts): https://youtu.be/YWUhwmmZa7A?t=667

Travis Snoozy

I can flip the fan if that helps

ElectroBOOM [Mehdi Sadaghdar]

I have that same Digi-Key ruler :)

Scott MacLean

Try CPU water cooling kits with bigger water block and that will definitely show some major difference I made one that can reach and maintain -8°C and I'm using it as air cooler, but unfortunately it wasn't enough to cool the whole room but it is enough to throw that cold stream of air at your face, and which is heaven 🤤🤤where I live coz the temperature here easily reaches 50°c after 12pm😅😅, BTW YOU SHOULD COMPLETE IT FULLY AND THIS WILL SOLVE YOUR EXCESSIVE SWEATING PROBLEM DURING VIDEO MAKING 😂😂😂

Always entertaining.

GC

I bought one about a year ago. Powered it up and burned my finger. Put it away, and forgot where it is. That sums up my experience.

Chuck Kirchner

Nice video.

I can feel the joy while you are building it :D

Hacksaw to cut wood, nice....

The problems you had with airflow are why fans always pull air through a heat sink instead of blowing it through. Your solution was great though!

This metal test in shop was fantastic.

Weeks of work and >100 watts to run 2 LED’s!!!!! Awesome. Why doesn’t anyone believe in free energy?!?!! :-)

1st!