The device has a nimh power pack which stores electrical energy for use whenever you need it, the power pack can be detached for use anywhere. The output is 5V through a USB port. This device would work especially well were there is snow available for extra cooling – for example off grid cabins in remote (snowy) locations. It could serve as dual purpose - melting snow for water and producing electricity ? The bigger the temperature difference between the two sides of the peltier the greater the power output.
This idea is not new, it has been around for a long time. See here for some very
old thermoelectric generators
The peltiers produce 0.6W of power to recharge the battery pack.
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Here's what you'll need :
Step 1: Tools and Materials
- 2 x TEC-12706 Peltier Modules
- DC-DC USB Step Up converter
- Small switch
- Project box
- Small scrap of vero board
- 4 x 3000mah nimh/ni-cd batteries
- 1N4001 diode.
- Battery holders for the batteries
- Miscellaneous wire, solder etc.
- Thermal compound
- Aluminium or copper milk pan
- PC CPU Heatsink
- 4 M4 x 12 bolts
- 4 Long (>75 mm) M6 bolts for the feet
- Electrical connectors (screw terminal type)
- Silicone tubing.
- Drill & drill bits
- M4 Tap
- Soldering iron
- Spanners to suit the bolts
Notes: The PC heat-sink must be big enough for the two peltiers to sit on.
I bought the DC-DC converter on ebay, it has an integral USB port.
Step 2: Mark Out Holes in the Pan for the Heat-sink Bolts
Step 3: Drill Holes in the Pan to Attach the Heat-sink
Step 4: Drill and Tap Holes in the Heat-sink for the M4 Bolts
Step 5: Lay Out the Peltiers
Step 6: Bolt It Together
Take care not to overtighten the bolts as this could crush the peltier chips.
Step 7: Slip Some Silicone Tubing Over the Wires
Step 8: Add Legs
Step 9: Attach the Legs
Step 10: Attach the Screw Terminal Blocks
Step 11: Connect It All Up and Test
Connect a multimeter to the output and measure the voltage. If the voltage is very low, such as 0.1 – 0.5 volts, then one of the peltiers is probably connected the wrong way around. Flip the wires around on one of the peltiers.
It will take around 5 minutes for the heat-sink to reach full temperature, at this point you should see between 3 – 7 Volts DC output.
Step 12: Build the Step Up Circuit
Note: The 3.5mm jack shown was not used in the final build.