Recent content by Phong Do

How thick is that copper plate?

Ah, ok. That makes sense. I had thought the wood part was the center. Thanks for the clarification.

Do you tighten the center of your coil after you're done winding it on the jig? The center on the finished coil looks smaller than the center on the jig.

@Einstein, how many turns are in your pancake coil and do you recall how much wire you used for it?

I have 5 lb of iron oxide powder for another project. I might try using it for the core of the electromagnet and see if it helps with the heat. I'll have to find some thermal resistant epoxy as the binder.

It sounds like the heat generate is from eddy currents then; 21 awg should be able to handle 0.68 amps just fine. Agreed, ohm's law doesn't work directly with AC current so the calculations have do be done using rms values which is the DC equivalent for AC. As for soft iron, I think I'm going...

The other alternative that I had in mind was to put an additional power resistor in the circuit. 21awg wire is only rated to carry 1.2amps of current, so with a voltage of 120v (84.853V rms) the electromagnet needs to have a total resistance of 70.71ohms. 1000 ft of 21awg wire has 12.8ohms of...

There doesn't seem like much you can do in 10 minutes. If you're meditating with the device, you'd limited to 10 minute sessions.

Einstein, you mentioned before that you were using rolled steel and that because it has carbon, it will heat up. Do you think a different material for the core of the electromagnet would help with the heating? I was thinking of making a core out of iron oxide and epoxy as a binder.

Has anyone had problems with the electromagnet heating up too much?