Thane Heins Perepiteia.

[Steven Dufresne]

After reading this thread for a while I thought I might try my hand at the Heins transformer. What I did is a little different from all of your experiments in that I took a standard 120 volt to 12 volt  ac transformer...

Vince,
I can't picture what you did from your description. Any chance you could upload a simple sketch? If so, could you make clear which parts are which core?
-Steve
http://rimstar.org

[LarryC]

Larry,
Thanks! Do the ceiling fans have high permeability cores to keep the amount of copper down, and hence the weight down? I just bought a dirt cheap, $15.00 ceiling fan on sale but was looking for any insight about if there's a certain type of ceiling fan that wouldn't have it before I rip it apart. It's returnable but probably not after I've broken any pieces.
-Steve

Steve,

Grain oriented silicon steel is used in most motors and transformer as it has high permeability and is cheap. If your ceiling fan is in the shape of large pancake, then it is most likely the correct type. The fan motor that Vince has is a shaded pole induction motor used in many vent fans.

If you use the toroid from the ceiling fan, be aware of the fine slanted lines in the toroid. They are die cast aluminum which is connected at the top and bottom with a continuous bar of aluminum. The rotors magnetic field induces a current in the connected lines to create another magnetic field. The top and botton bar should be removed so that this does not happen. The fine slanted lines do not go completely thru the core, so it should'nt cause much of flux problem.

Larry

[LarryC]

@gotoluc,

Thanks for all the great info.

I'm a little concerned about the permeability of 200 on the primary. It seems like it would severly restrict the amount of flux going to the secondary and reduce the available power considerably. Could it be that a zero or a couple of zeros were chopped off in the picture?

Thanks, Larry

[Steven Dufresne]

If you use the toroid from the ceiling fan, be aware of the fine slanted lines in the toroid. They are die cast aluminum which is connected at the top and bottom with a continuous bar of aluminum. The rotors magnetic field induces a current in the connected lines to create another magnetic field. The top and botton bar should be removed so that this does not happen. The fine slanted lines do not go completely thru the core, so it should'nt cause much of flux problem.

Larry,
Please see the following pictures. There are some numbered questions on one of them. Also, how delicate do I have to be in tearing this apart?
-Steve
http://rimstar.org

[LarryC]

Larry,
Please see the following pictures. There are some numbered questions on one of them. Also, how delicate do I have to be in tearing this apart?
-Steve
http://rimstar.org

Steve,

Actually, I'm surprised at the amount rust in a new fan motor. I had to replace the bearing in three of my frozen fans after Katrina and the toroid had less rust.

Everything should be removed above and below until you can see the fine thin lines on the top and bottom. I'm not sure about the green as mine didn't have any, but as long the thin slanted lines can't conduct it will be okay. You may be able to use a chisel on the aluminum and if that doesn't work a grinder will. The steel is a lot harder and if you are careful it shouldn't mess up too much. I would put tape or clamps around the sections you are not working on to keep the steel laminations together as they usually are just held together with an insulating epoxy to reduce eddy currents. A note of caution, some of these items may contain lead, so a mask is recommended.

All,

The Bi-Toroid transformer can also be reproduced by removing  the center steel out of a EI type transformer. Then replace the center with a lower reluctance member. Someone stated that a toroid was more efficient but it appears that this would still work. I would wait on gotoluc answer to my permeability question before getting a primary member.

Regards, Larry