If you weld two rods of different metals together and start heating the joint, a slight voltage will appear at their ends. At the beginning of the last century, heat generators were made using this principle to power walkie-talkies, which removed energy from the heat of the fire. You can repeat such a device at home, building it on the basis of Peltier elements.
Materials:
- 4 Peltier elements - http://alii.pub/5p40l2
- boost converter to 5 V - http://alii.pub/5p40ra
- thermal paste - http://alii.pub/5p40vy
- aluminum profile pipe 20x20 mm;
- steel plate;
- steel scraper for washing dishes;
- candle tablet;
- sheet aluminum or 40 mm strip.
Manufacturing process of thermal electric generator
To make a generator heat exchanger, you need to cut 4 blanks from a profile pipe 60 mm long.
They are drilled. 3 side walls made of aluminum strip 40 mm wide are screwed to the resulting sections. They are bent at the bottom to stabilize the structure. The window they form under the heat exchanger is necessary to insert a candle.
For a Peltier element to produce electricity, one side must be cold and the other hot. Therefore, for each of them you need to assemble a radiator. It is made from the same aluminum strip or sheet as the side walls of the heat exchanger. The radiator consists of 3 blanks of different sizes, bent at both edges. Their fins must have such a bend angle that they do not interfere with adjacent radiators on the heat exchanger. It is convenient to bend by pressing the plates in the center, first with a 40 mm profile pipe, then 25 mm and 10 mm.
The radiator parts are drilled and lubricated with thermal paste in the contact areas. They need to be tightened with countersunk screws. Next, you need to clamp the Peltier elements between the heat exchanger and radiators. With this configuration, this cannot be done with screws, so you can use clamps made of thin wire.
The thermoelectric generator is ready for use. A loose scraper for washing dishes is pressed into the tubes of its heat exchanger. It will allow you to more effectively remove heat from the candle.
A spark plug is installed under the generator. In this form, it already produces almost 1.5 V. This is not enough, so you need to connect a 5 V converter. For stability, it is better to screw the generator to the bottom of a metal bowl.
To make the device generate more electricity, you can insert 2 additional wicks into the candle.
After such modification, 4 Peltier elements produce almost 5 V. However, this is not enough to recharge a smartphone. The phone sees charging, but its current expenditure on the screen backlight is higher than the influx, so it will be discharged. You can only charge an old push-button mobile phone when it is turned off. In reality, the charge is only enough to power a simple Arduino or LED lights.
