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ennoid57 (July 25, 2008 at 4:05 am)
physics teacher dude, you have awesome information thats not boring
wbeaty (July 24, 2008 at 6:38 am)
> quick step-up transformer? Easy: add a thousand turns of wire to the generator! :)I made several tries but gave up. The AC frequency is too low. Now if the magnets could spin at a few thousand RPM, then maybe we could run transformers.A transformer needs to draw almost no current, which means the primary must have a huge inductance. Pounds and pounds of iron and wire, and worse at low AC frequency.Note that magnets make poor iron cores: they're stuck in full-magnetized mode.
fullofhate77 (July 24, 2008 at 5:44 am)
How can I make a quick homemade step-up transformer? I tried with a disk-shaped magnet and some magnet wire. I wrapped more turns on one side than the other, but I get no current at all on the side that should be stepped up. What am I doing wrong?
wbeaty (July 24, 2008 at 2:05 am)
> my magnets are slipping on the nailMine slip a bit too, but I find I can spin it fast enough.Improvement: get a roll of double-side foam tape from stationery store, cut some 3/4" cardboard and tape squares, then stack them on the magnet on either side of the nail so the nail sits in a narrow slot. Adjust the amount of tape and cardboard so the gap between magnets is a bit smaller than the nail. Adjust it so it's hard to push the nail between the magnets when assembled.
acosalvo (July 23, 2008 at 7:27 pm)
any advice, my magnets are slipping on the nail
manstaha (July 23, 2008 at 12:32 am)
rap the wires to cover the opening of the box also, would it be better if the box contructed of thin copper or silver sheets, or must it be of wire?
chewyman5000 (July 21, 2008 at 11:06 pm)
Your a kewl cat :D
wbeaty (July 20, 2008 at 7:07 pm)
> powering something that takes DCCheck the website: add a diode, then add lots more turns of wire to make up for the 0.7V eaten by the diode.Yes, Faraday discovered induction. Then Maxwell/Hertz/Heaviside saw that a moving magnet creates an e-field (a voltage.) But Einstein looked at relative motion in E&M theory: his Special Relativity *explains* induction.Note that the e-field around a moving magnet is circular. If we pass more turns of wire through it, we intercept more volts.
Dragonstud (July 18, 2008 at 12:32 pm)
can i come and work with you!!! looks like lots of fun hehe
coolbluelights (July 18, 2008 at 12:22 pm)
this is a perfect hands on classroom demonstration! I wish we did this in my science class! |
