High Current.
Posted: Thu May 19, 2011 2:05 pm
I'm contemplating setting up a Helmholtz coil to provide a large magnetic field in an experiment. Not 'strong', just several 10's of Gauss needed in a big volume.
I've stacks of 4mm^2 single cable I bought some time ago when Farnell was selling of 100m reels of the stuff at 5 quid (~$7) a reel. The copper alone is around 3kg per reel! So with that I am planning just 30-40 turns or so at ~100 A.
Now, it is the 100A I am wondering how to go about applying in the cheapest way poss. I'm wondering if anyone has any bright ideas.
My 'best plan' to date, because it is cheap and I already have generally all the bits needed: I take a 12 V automotive battery (big diesel one, with high crank current - I hope it still 'lives' not used for a while) and parallel up a few high current IGBTs, and switch them with variable duty cycle, in the 20kHz range, into a big capacitance.
Any advice? Is it this easy, or more difficult than it looks and I should buy a proprietary power supply?
I've stacks of 4mm^2 single cable I bought some time ago when Farnell was selling of 100m reels of the stuff at 5 quid (~$7) a reel. The copper alone is around 3kg per reel! So with that I am planning just 30-40 turns or so at ~100 A.
Now, it is the 100A I am wondering how to go about applying in the cheapest way poss. I'm wondering if anyone has any bright ideas.
My 'best plan' to date, because it is cheap and I already have generally all the bits needed: I take a 12 V automotive battery (big diesel one, with high crank current - I hope it still 'lives' not used for a while) and parallel up a few high current IGBTs, and switch them with variable duty cycle, in the 20kHz range, into a big capacitance.
Any advice? Is it this easy, or more difficult than it looks and I should buy a proprietary power supply?