Microwaving a Ferrite Toroid

7 assorted junk-box toroids: 3 ferrites, 2 crummy MicroMetals powdered iron, two permalloy powder, 5 seconds in a good microwave.

Ferrites are just about too hot to touch.

MPPs are a little warm.

Powdered iron about room temp.

John

lol :)

Could it be that the ferrite is hottest because it has the highest density of polarizable matter. The more polarizable, the higher the eddy currents and therefore more heat.

D from BC myrealaddress(at)comic(dot)com British Columbia Canada

I found a trashed microwave years ago. I just wanted the xformer..but couldn't resist doing the detective work to find out why someone trashed a nice microwave.. Dead diode. (Bench power supply test.) IIRC diode was $6.00 to replace.

Took out xformer...trashed the rest. :P

D from BC myrealaddress(at)comic(dot)com British Columbia Canada

Then why not just put the core/hst assembly in the oven, start it, and when the tube shrinks or starts to scorch, turn the oven off.

If you don't have a heat gun, invest $1.00 or so in a lighter. ;-)

Have Fun! Rich

Free, if you know where to dumpster-dive and can replace a fuse. ;-)

Cheers! Rich

In article , snipped-for-privacy@comic.com says...>

Pretty expensive considering the whole deal can be had for $50. Of course I've thrown out perfectly good microwave ovens. ;-)

Microwaving might be faster and more fun. :)

I do have one of those butane torch pens with the tip for heat.

D from BC myrealaddress(at)comic(dot)com British Columbia Canada

D from BC writes

I enjoyed this thread... posting that question was kinda like putting a candy bar in front of naughty children and saying "DON'T eat this when I leave the room". It was just a question of who'd break first.

--
Nemo

The audiophiles might be trying it out.. You know...for that warm microwaved ferrite sound.. :P

Here's an experiment to try: Does a ferrite toroid in a cup of water boil faster in a microwave. ?

Note: Compare with same volume of water.

If ferrite is better than water at converting uwave energy to heat, the cup of water might boil sooner..Beats me..just guessing.

Huhh..there's always a problem.. Nucleation sites are needed or the water will superheat.

Better to compare temperature with a thermometer after x time in uwave.

D from BC myrealaddress(at)comic(dot)com British Columbia Canada

I've collected discarded microwaves, and it was usually just tossed because it was replaced by the latest model. Otherwise, it's been the fuse - or was that TV's? ;-)

Didn't you salvage the maggie magnets?

Thanks, Rich

You should also compare with the same _total_ volume, just for completeness. ;-)

Cheers! Rich

Neo?

D from BC myrealaddress(at)comic(dot)com British Columbia Canada

Not in the ones i've seen, just that black ceramic stuff used on loudspeakers.

put the two cups in at the same time - else you may have different signal strengths in the cavity.

I'm almost tempted to try.. Maybe it leads to a product idea.. A coffee cup that heats water faster.

Call it the FairRight Coffee cup.. :)

D from BC myrealaddress(at)comic(dot)com British Columbia Canada

microwave ovens are mostly constant power, present them with a larger load and they'll produce a weaker signal level.

all you gain is the energy from reduced losses due reduced signal levels reducing parasitic losses in the cooking cavity (less heating of the walls and platter etc...)

What?

Thanks, Rich

I thought maybe neodymium magnets were used.

Somebody posted, ceramic.. D from BC myrealaddress(at)comic(dot)com British Columbia Canada