Building Your Own Mini Fridge?

Ever play with a Peltier plate? They’re these really cool components that kind of look like a ceramic sandwich, and when you put power into them, one side gets hot, and one side gets freezing cold! [Joseph Rautenbach] decided he wanted to try making his own mini fridge out of one — which is typically how most modern mini fridges work these days.

The peltier plate he’s using draws 12v at about 3.5 amps — so about 50W — and if you don’t heat sink it properly you could burn it out in a matter of seconds. Peltier plates only care about the temperature differential between the two sides — if you don’t take the heat away from the hot side, it will soon overheat and destroy itself.

[Joe’s] using a styrofoam cooler for the fridge with a pair of computer heat sinks and fans for the peltier plate, and a temperature PID controller he bought off eBay. The external heat sink sucks away the excess heat generated by the peltier plate, and the internal one helps spread cooled air around the inside of the styrofoam cooler. The PID controller allows him to set a preferred temperature to maintain in the box, which will then control the outputs to keep it that way.

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USB Charger Solves Mongolia Electricity Problem

thermoelectric

People living in remote areas of Mongolia do not have access to electricity or gas, and rely on traditional wood stoves for their homes, which are used almost all the time. Many use solar panels to generate some electricity for small tools, but unfortunately there are often times when it is cloudy for days on end. [Chingun Has] saw this problem and created his own clever solution — a small thermoelectric USB charger.

[Chingun’s] device features an array of peltier plates inside of an aluminum shroud. The device is designed to sit on top of a stove, or to be strapped onto a stove pipe. When there is a large enough temperature differential between the two sides of a peltier plate, a charge is induced. He’s using a small fan to help cool the other side of the peltier plates. A small control box houses a voltage regulator circuit that provides 5V over USB.

The cool thing about this project is that it is partially the result of [Tony Kim], an MIT professor who traveled to Mongolia to teach students an edX circuits course about a year ago. [Chingun] was one of his students, and this is a great example of a solution to a real-world problem.

An excellent video after the break gives a complete explanation of the project, as detailed by [Chingun] himself — it’s well worth the watch!

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