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Charge Your Cellphone Using Wasted Heat (and Build a Steampunk Wall-E)

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Step 8: Frequently Asked Questions

We've been asked these before so we decided to answer them for you ahead of time.

1. Is a seebeck the same as a peltier unit?

Almost. You can use any thermoelectric in either way but a peltier is optomized to cool while a seebeck is optomized to generate power. A peltier could be used to generate power but as our video shows its not as efficient as a seebeck is. It took around 700F Delta to generate 5V with a peltier, the seebeck only required 200F. You can buy peltiers on Ebay for a lot cheaper than a seebeck. To get the same power you will have to use more peltiers so it would mean you would need more heat and more cooling. that may defeat some of your efficiency. Plus at 700F the wires tended to melt off for us.

2. How would you improve the design and draw more power?

Well just like batteries or solar panels you can stack more in parallel to draw more current, or more in series to get more voltage. If manufacturers could make these in flexible strips we could wrap them around pipes like the engine exhaust and that could generate some serious power. See the extras page for more info on this.

3. How is a blowtorch green?

It isn't, that is why we recommend using a wasted heat source that would otherwise be vented into the environment.

4. Do you need a heat sink?

Not always, but it will work better. They won't generate the full power if you don't heat sink the other side.

5. Are you really planning to make a store out of the laser cutter?

Yes we are, we were planning to launch www.splitreaction.com on July 20th as a blog, but since our main idea fit this Instructables contest we decided to jump start and rush to finish it to make the deadline.

6. Why does your current boost circuit not work for iPods?

We built that boost circuit for a super cap powered LED flashlight. Its only designed for 100mA. It will allow a charged super cap to output 5V steadily from 5V to 1.8V input. Since I-pods and phones need more current our current boost circuit wont charge them. We do plan to improve it.

7. When will you be providing the circuit board design?

Hopefully by July 20th our full blog will be up and we will have perfected a boost circuit.

8. Will a Minty boost work with the thermoelectric element?

Maybe. We don't own one. Perhaps we can collaborate.

9. OMG these seebecks are expensive.

Yes they are, but over time they compensate for the initial cost of the purchase. Not to mention, the prices should drop dramatically when large manufacturers see the benefit and start creating them in larger quantities.

10. Why do you use a regulator?

The voltage is very unstable and varies with changes in the temperature, without regulation the element could go way beyond what you want and possibly damage your device.

11. Can it charge a super cap?

Yes it can, and with a efficient boost regulator it could power almost anything you could think of.

12. Are you going to sell kits?

Maybe if enough people request it we can order parts in bulk and kit it out.

13. Will the $15 350W Peltier from Ebay work? It seems bigger than the 6W you use.

Well it will... kinda... but not as well as a seebeck one would. They use different metals to make them. Also the 350W number is how much energy it consumes to cool, not how much power it can generate.

14. I don't know how to solder or do any of this, but I still want to try it out. Where should I start?

It's not the easiest thing to do, but start off by browsing Instructables. They have plenty of How-tos that will build you up to the expertise you need to try this one.