Permanent Magnet: ON/OFF Mechanism...

[PaulLowrance]

We're assuming it only works at 180 KHz. I suspect it can vary to some degree, especially if the PM is very thin compared to length. Was it Liberty who posted link to similar work that mentioned 170 to 175 KHz?  This theory works nice so far. If you double the width of the PM (doubling L) then C cuts in half. We know resonance is:

F = 1/(2pi sqrt(LC))

If L doubles and C halves then we still have the same frequency.

Paul Lowrance

[Esa Maunu]

I think it is important to have very sharp edge DC pulses, and then try with different frequencies in this experiment.Here you can find a diagram for this kind of circuit,that can be driven with function generator.

http://jlnlabs.imars.com/spgen/index.htm

This uses IRF840 Mosfet switching transistor, that is very near the "ideal" switch, switching time is about 80 ns.

Esa

[bitRAKE]

Might be a good idea to experiment with magnetic fluid to see the effects of waveforms applied to the magnet.

http://www.mi.sanu.ac.yu/vismath/takeno/index.html
http://web.mit.edu/newsoffice/2003/ferrofluid-0205.html

Here is how to make Ferrofluid:
http://mrsec.wisc.edu/Edetc/nanolab/ffexp/index.html

[cheap1_2]

Thought you guys might want to look at this its concerning 180khz http://www.rexresearch.com/coler/colerb%7e1.htm#II1

[PaulLowrance]

That's pretty interesting. There seems be a lot mentioned about 180 KHz

http://www.google.com/search?num=20&hl=en&lr=&safe=off&q=%22180+KHz%22+ferromagnetism&btnG=Search

Paul Lowrance