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.
Expert: Dan Fink Date: 4/18/2008 Subject: Heating a wire
Question How do I heat a nichrome wire without burning through plastic? How much
energy does it need and how hot does it get? What thickness of nichrome do we
need to get? How are we supposed to control the heat and turn it on and off?
Answer Hi Leah -- that depends on your application, and your power source. What are you trying to heat up? The basic procedure for designing an electrical circuit like that is as follows:
You'll need to figure out how much heat energy you need to make in watts...for example a toaster is about 1,000 watts, while a handwarmer might be only 20 watts. The nichrome wire manufacturer will supply you data on resistance in nichrome of different diameters--how many Ohms per foot.
Then, you use Ohm's law to calculate how much of what thickness wire you need. Thinner nichrome gets hot with less electric power than thicker wire, but not as much power will be flowing....so whatever it is you are heating won't get as hot.
These pages from a nichrome wire supplier has all the has all the tables and math you need: http://www.wiretron.com/design.html
