Where's everyone. Maybe everyone's building one of these now, including myself.     The only difference is that I'll include a measurement to see if there's bemf >when there is current in the toroid coil!<  To say there's no bemf when there's no current is meaningless, which is what I've been trying to tell everyone far before MH even said anything. Someone in another Steorn thread said that MH is getting the credit, lol.

So IMO the excess energy would be due to magnetic viscosity, so don't think this task will be easy. Congrats to Steorn on an awesome achievement!!! And congrats to Ben & J.L.Naudin on a great first build.

Hi All,

I must apologize...

I am getting old, it seems:
After 2 hours of calculations and trying to drive my brain mad,
I came to the conclusion, that I was posting something wrong earlier,
when I said, one could extract about 90 % of the inputed coil energy.

Now after recalculation I came to the conclusion that I was wrong and
mixed something up.

The numbers are a bit lower.

If you have a RL series circuit and put an constant voltage pulse in it
with a varying time:

Vsupply x i(t) x t = Input Energy
where
Vsuppy is the constant voltage
i(t) is the current through the RL series circuit
and
t= switch-On time interval
tau= L/R timeconstant

you can calculate the input energy for the time t.

Now input energy for this time interval is defined as:
Vsupply^2 / Rcoil x ( 1 - (e ^-(t/tau)) ) x t

This is the total energy drawn during t from the constant voltage
power suppy.

Now we can compare this with the energy stored inside the coil
which is Wcoil=0.5 x L x i^2

We will find the coil current after the time interval t with the formular:

i(t)= Vsupply / R coil x ( 1 - (e^-(t/tau)) )

So if you calculate i(t) after the time interval and put it into
Wcoil=0.5 x L x i^2

you will know the stored energy inside the coil and then
you can divide this value through the input energy
value:
Vsupply^2 / Rcoil x ( 1 - (e ^-(t/tau)) ) x t

As the results you get:
if you choose:
at
t= 1/10 tau you store 47 % of the energy input into the coil
t= 1/5 tau you store 45 % of the energy input into the coil
t= tau you store 31 % of the energy input into the coil
t= 5 tau you store 15 % of the energy input into the coil


So you see, at 1/10 tau Ontime you can only recover less than
47 % of the input energy back into a capacitor.

So it was not 90 % but only less than 47 %.

But still this is a way to avoid too many losses
to just switch on only  way less than tau and
use a high supply voltage so the saturation current level
is already reached during this short ontime interval.

Regards, Stefan.

The setup consist of a toroid with coil winding and a dremel motor. On the end of the dremel is a round piece that allowed me to attached 4 NdFeB magnets, two on each side (180 degrees apart). If we look at one side (two magnets) we'll see one magnet that is facing us is south and the other magnet is north. The toroid coil is not loaded and there's no current flowing through the coil.

A bunch of people at overunity dot com have been discussing how the Steorn eOrbo might be working, and I've been doing similar magnetic simulations in FEMM for years. So I decided to slap together a quick experiment to see if I saw a particular effect. While running the machine, I kept noticing how cold it appeared, but thought that was due to air circulation. So I grabbed the non-contact IR gun and to my surprise the machine was colder than ambient temperature. So I mounted everything, the dremel motor, the IR gun, and took this footage.

The ambient temperature is over 67F. The dremel had been running for while earlier, but the dremel and everything was resting unused for ~ 1/2 hour prior to taking this video. So IMO the temperature of the dremel was not that high during this footage.

The wires connected to the toroid are connect to a volt meter, the oscilloscope, and a power supply, all of which were off during this footage.

One thing that seems odd is that the dremel rpm will suddenly change by a lot. I've used this dremel a lot, and it never varies like by itself. It seems the load or magnetic viscosity in the toroid is greatly varying.

This is inconclusive, as I need to be certain. It's just too good to be true. If I find out anything new I'll post another video. Thanks for any positive feedback.