(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

I'm working with a stripped-out microwave oven transformer core. I've split off a stack of laminations 1.25" thick, and cut out the middle leg of the "E" lams.

I want to build a hollow-core 1:1 isolation transformer, and input a slow (about 3 Hz) pulsed DC current through it that will cyclically induct the core to 16,000 gauss.

I am aware that this will be an inherently inefficient transformer. The current and power required do not particularly matter--it's the flux in the core that I want to tinker with.

The sectional area of the core is 0.744 sq. inches, and the Mean Path Length is 12.375 inches. The relative permeability of the core is (probably) 40,000. There is no air gap in the core.

I've been banging on the numbers for almost two weeks and I'm not making much headway, other than learning that transformers are a lot more complicated than they look.

I really need some help figuring out the coils for this critter.

So far I've gotten answers ranging from 12 to 223 turns of 30-ga magnet wire running at 0.13 amps, and I could be off by an order of magnitude, or more. And, somehow, I don't believe that a half a watt is the right amount of power...for a core that weighs about 4 lbs.

2. Relevant equations

If there are any around, they are definitely in hiding.

3. The attempt at a solution

Tried a lot of different ways, including working up an air core coil and correcting it for an iron core, but none of the answers I've gotten look even remotely reasonable.

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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# Homework Help: Transformer problem

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