TV Researcher Needs Help W/ Electromagnet

[cmjwmprod]

Hi-

I'm a researcher for a TV production company, and I'm trying hammer out a basic idea - perhaps members of this forum could enlighten me a bit, as my science knowledge is a bit weak...

How powerful of an electromagnet could I create with an iron manhole cover, wrapped with rather thick wire and a (or a few) car battery(ies)?

Is there a next step up in powering a magnet like this without tapping into the power grid?

This being TV and all, the classic D battery & nail setup won't work. I have visions of a making a DIY junkyard magnet, making things like monkey wrenchs leap. I could very easily be misunderstanding this concept, though....

Thanks,
Chris
cm.jwmprod@gmail.com

 

[MJR2]

Chris,
DC magnetic fields such as you want are generated by amps of electricity and turns of wire, amp-turns.

I venture a manhole cover to be perhaps 30 inches in diameter. To make this into a resonably good lifting magnet you would want to get to something called magnetic saturation. That might require say 250,000 amp-turns. That is 1 DC amp and 250,000 turns of wire or 250,000 amps and 1 turn or some combination in between.

Plus it would be a poor magnet since there is not any backbar to focus the flux.

You could use the cover as your backbar and chose a smaller core. Then you might be getting somewhere. Search the web for specs on magnet and you will see the power requirements.



Mike