I don't want to sound like a jerk...

[Tink]

I am not sure about the Emerycoil claim, it can be true but also not be true.
I haven't tried it yet but a posting on http://amasci.com/weird/unusual/exper.html made me think there may be some truth to the Emerycoil.
Here is a part from that post;

Weird Transformer Effects

All,
One you can try at home easily and it's paradoxical and bizarre!

I have a toroidal transformer with a primary and secondary. Turns ratio is irrelevant but primary is 6V to secondary 240V (ie 1:40). Now Imagine this setup (this is done with relays so every goes back to high impedance, o/c):

Primary to a voltage source:
         ______
         |       |
         |       |
         |       |
-------        ------------------------

Secondary shorted by relay:
             _____________
            |                    |
            |                    |
            |                    |
---------                     -------------------------

Assume that on primary side we have given enough time for transients to die away so that steady current in primary. We then short the secondary. FACT when we do this, no effect on primary side (as you'd expect).

WITH SECONDARY STILL SHORTED. Disconnect primary current. What happens? You'd expect to see a back-emf in the primary? Hang on flux links the secondary too, so you'd see one there too, right? FACT: nothing!!

So what happens when you eventually unshort the secondary (the primary is o/c)? (Eventually could mean seconds, days, weeks, months, years ...) FACT: You see a back emf in the primary!! (Finally!)
(End part/)

I haven't tried it yet myself so can't tell if it's true what is claimed, have some of you tried this experiment?

[Elvis Oswald]

The emory coil works absolutely... but it's not working in any mysterious fashion.  If you have a magnet in a coil and the magnet is turned off... the field collapses and generates current in the coil.

A transformer works the same way.  Alternating current in the primary induces an alternating magnetic field in the core and that produces alternating current in the secondary.  Current is produced once when the field is built and again when the field collapses.

I can guess about the experiment you described and say that by shorting the secondary you are holding magnetic current in the secondary... and when you unshort it, the field collapses and generates an electrical current in the primary.
As to what does or does not happen when the short is made with power to the primary... that would vary depending on the cycle of the ac input... and the resonance of the coils.

[valveman]

"I can guess about the experiment you described and say that by shorting the secondary you are holding magnetic current in the secondary... and when you unshort it, the field collapses and generates an electrical current in the primary."


I'm missing something here!  As soon as you short any coil, the field collapses causing a current to flow in the opposite direction that created it and die out.  To maintain a magnetic field, current must be flowing in the coil.  Something else is going on here.

Valveman

[jake]

Jack,

Nice work on your motors.  They are truly works of art.  Beautiful craftsmanship.

I would like to offer to help you test your motors.

I am an electrical engineer.  I own and operate a business in southwest Ohio.  We specialize in industrial automation and motion control systems.  It appears that you probably live within a couple hours of me if I am guessing correctly.  I am willing to travel to your facility to observe testing, or you can come to my shop and use my equipment to conduct testing.  For that matter, we can meet somewhere to do the testing.

[Liberty]

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