AboutDan Fink Expertise Though my experience is mostly in the fields of electricity, magnetism, and physics, I have a broad science background. My career is in the field of alternative power sources -- solar, wind, water and battery power. But any questions about electricity, magnetism, energy conservation, power generation, electric motors, and even general physics are very welcome--especially from kids. They ask the best questions of all! I pride myself in answering science questions accurately, with ideas for SAFE, easy experiments that kids can perform by themselves--and that let them prove the answers to their own satisfaction. I think science should be fun, and available to everyone, regardless of age.
Experience I have volunteered in our local public schools for 5 years. I currently make presentations at our schools about electricity and magnetism, with a focus on solar, wind, water and other alternative power sources. I try to demonstrate at our schools how easy it is to make electricity, with simple devices using spinning magnets and coils of wire--powered by wind, water, bicycles, gerbils...etc. And of course solar panels! I am the webmaster of Otherpower.com, an alternative energy website. I have lived 10 miles from the nearest power pole for 11 years--I make all my own electricity from scratch with sun, wind and water.
Publications Otherpower.com
Wondermagnet.com
Co author of the book "Homebrew Wind Power" ISBN 978-0-9819201-0-8
My articles appear regularly in such magazines as Home Power and Back Home Education/Credentials BA Technical Journalism
Question I am in 7th grade and for my science fair project I want to take an aluminum (cheap thin kind) candle holder and put a small heating element under or around it, hoping to melt the wax a little so that I don't have to pick it out with a toothpick before putting in the next candle.
How could I make or buy one that is preferable battery operated and will get warm enough to melt the wax but not too hot and safe so that I do not electrocute myself.
Thank you for your help
helen
Answer Hi Helen. Sounds like a fun project. You'll have to do some experimenting to get the heat level right, but your idea sounds totally feasible.
What i would do is find some Nichrome wire, which is used for making heating elements such as in toasters.... Best local source would be a good hobby store that stocks all the stuff to refill chemistry sets. Otherwise, try science hobby suppliers online. You'll need 5-6 feet to experiment with.
What I would do, is also buy a linear-taper potentiometer at Radioshack (less than $2)....that way you can easily change the resistance. You can also change the resistance by using longer or shorter strands of nichrome wire, or multiple strands. That web page above will help you. The longer the strand of nichrome, or the higher you dial up the potentiometer, the less heat you'll get.
You might also want a cheap multimeter from radioshack for knowing how much power your heater is using. I'd go with a standard 9v battery, they are small and have quite a bit of power. A 6v lantern battery would also work well, and would last longer. There is no shock hazard from either of these.
When you first start experimenting, you might very easily get the wire red hot, so be careful! And, nichrome wire is NOT insulated, so might want to put the nichrome wire in the inside of a glass candle holder instead of outside a metal one -- if the loops of your wire touch each other, or the metal candle holder, the heater won't work and the battery will drain in only a couple minutes.
The way i would start (after reading that web page above) is hook one battery terminal to the center terminal on the potentiometer and the other battery terminal to one end of a 30 inch piece of nichrome wire. Get ready....and connect one of the outside terminals on the potentiometer to the other end of the wire. turning the potentiometer will adjust the heat. You might need a longer piece of nichrome for less heat, or a shorter one for more heat, too....you can adjust it with the potentiometer too. You'll probably drain a few batteries while getting the heat level right, so have spares.
I hope that helps you get started. Feel free to ask followup questions, I love science fair projects!
DAN
