anybody built a controlled demagnetizer?

[marku52]

I'm thinking about a couple hundred turns of pretty beefy stuff with an air core to put the magnet in, use a variac to control the amount of demagnetization (I'm trying to approximate the Br of A3 with A5)

Or how about cutting into the lam stack of a power transformer and putting the magnet in the created air gap?

[marku52]

OK no body bit. I've had some success using a tape head demagnetizer and a variac to control the coercive force. keep upping the variac until you get the amount of demag required.

[copperheadroads]

Id say get a gauss meter & a bunch of small neo magnets ,then you can see exactly what gauss your trying to acheive