TEG Smartphone Charger [TCD for TU Delft]

A ThermoElectric Generator module (TEG) can convert heat into electrical energy. In the K-Stove off grid energy project, TEG’s have the potential to use the waste heat created by the stove to power nearby appliances. The stove itself requires a small electrical current to ignites the pellets each time it starts. The concept is that electricity generated from the waste heat can be stored in a battery and used to turn on the stove. Cold water is piped through the stove. A module placed between the inlet/outlet can produce electricity. In this case fire is used to create heat around 400 degrees with the passing water around 10 degrees.

This project is part of the Technologies for Concept Design from the Advanced Concept Design course at the TU Delft.

David Randles - 4546091

Jasper van Hijfte - 4132858

• USB-cable (expendable)
• 0.6 mm wire
• Electrical tape (red + black)
• Wire cutter
• Wire stripper
• Soldering iron
• TEG-module (12A ~106W) 40 x 44 x 2.8 mm
• Hot-cold source (smartphone)
• Optional: connector blocks or clamps

Find a USB cable you won't miss and make sure it has the output end that matches your smartphone's charger

port.

The wire works to strengthen the connection to the TEG module and increase the durability of the setup.

The cutter and stripper are used to work with the cables and wires, which are connected with a soldering iron to improve the electric conductivity throughout the wire.

When the wires have been prepared, they are connected to the TEG using solder or connector blocks or clamps if you are looking for a more temporary solution.

Once you have selected the correct cable, decide how long you need the cable to be. I like to keep the cable short (about 10 cm), to decrease the amount of redundant cable surrounding the project.

• Cut the cable to the desired size using the wire cutters
• Trim the outer insulation shell to expose the inner wiring using the stripper. Cut of about 2 cm.
• Find the red and black cable and separate them from the other two. These aren't necessary for transmitting electricity, so you can cut those off.
• Strip the tubing of the red and black wires using the wire stripper. Expose about 1,5 cm of wiring.

Mind that you expose enough of the wiring to work with. If you expose too little, you'll have to redo this step. If you expose too much, you can always cut off the excess wires.

In order to increase the strength of the cables and later the connection to the TEG module, we add a 0.6 mm wire.

• Cut off 2 pieces of wire that are about 2,5 cm long.
• Push one end of the wire down to the insulation.
• Wrap the exposed wires from the red and black cable around a separate piece of 0.6 mm wire.
• Solder the wires to the 0.6 mm wire.
• Cover the exposed parts with electrical tape. Make sure the color you use corresponds to the color of the wires in the USB cable!

Make sure the 0.6 mm wires go all the way down to the insulation, as this will create a good physical connection. Using the solder ensures we have a good electrical connection too. You can also use shrink sleeves to indicate the colors of the wires.

For this step we are going to hook up the TEG element to the USB cable that is now sturdy enough to work with. Depending on if you want to make a permanent connection or not, you can choose to connect the wires and solder them together and cover them with electrical tape or a shrink sleave (be sure to put it on the wires before you start soldering!!). You can also use connector blocks (or clamps), as we have done in this Instructable.

• Expose the red and black cables to expose the wires.
• Put the red end of the TEG in the connector block opposite the red end of the USB.
• Do the same for the black ends.
• Tighten the screws in the connector block.

The TEG should now be hooked up to the USB cable with an end that you can connect to your smartphone! Use the heat produced by your smartphone to charge your smartphone.

This system works best if the temperature difference is as great as possible. The good thing about a TEG is that it has a 'hot' and a 'cold' side. If your phone is feeling very warm because you are using it a lot, put the hot side to your smartphone. The outside air will function as the 'colder' side. The other way around, if your phone isn't that hot, put the cold side to your phone and use your hand as a 'hot' source. As long as the difference is about 5 °C, the TEG should produce electricity.

If you want to check if your TEG can actually produce electricity, you can hook up a Voltmeter to verify the current that is produced. Ideally, a phone uses about 300 - 500 mA to charge, which is too much for a simple TEG to achieve. Your TEG will produce about 50 mA.