Hi All
Jean Louis Naudin is back with a replication of some russian induction heater cookplate
Tesla spiral bifilar coil transformer experiments
where it seems the output power is muchh bigger than the input power.

Here is his website about it:

http://jnaudin.free.fr/gegene/indexen.htm

and here is his youtube video about it.
http://www.youtube.com/watch?v=4W2ABWjeTrk

Here are the 2 referenced videos by the Russian experimentors:

http://youtu.be/6rzUnQ4v9z8

http://youtu.be/yT16-togIhw


Now the question is what kind of waveform does one get at the output of such
a flat Tesla spiral coil ?

Especially when the primary input coil in the heater unit is pulsed at high frequency
and the coil that Naudin has built is put into resonance ?

Are the eddy currents going into resonance and extract any heat energy from the environment
with it and convert it to electrical energy so the electrical output energy is higher than the input energy into the cooking plate coil ?

Hopefullythis will not just be any measurement errors again...
But both power meters show 1000 Watts input the one inside the cooker and
the other on the grid line...
Hmm...

Is it really so easy to get 1850 Watts of free electrical power this way

What do you think ?

Many thanks.

Regards. Stefan.

Hmm. Well here is a vid by Tinselkoala some time back.

In JLN's vid and Woopies vid, it seems the transmitting coils are standard pancake and the receiver coil is bifi.

TK shows that the bifi is a better transmitter than a receiver.

Other differences are that TK's spacing between coils seems larger.

Anyways, I think it fits here. 

http://www.youtube.com/watch?v=mvb39SwTXBE

Mags

OK, Naudin does connect a wattmeter that shows power factor - and that's nice but there could still be problems with frequency and spikes. DC is much better.
 
Still, it's interesting stuff and you gotta give Naudin credit for trying.

Hmm,
Naudin just posted an update:

http://jnaudin.free.fr/gegene/gegene05en.htm

and

https://www.youtube.com/watch?v=Iik6XnT2mE4


Seems he only gets now 91.4 % efficiency
when measuring the light intensity...

He says that he wants to do more tests.

I really would lke to see some scope shots of the involved waveforms from this.

Many thanks.

Regards, Stefan.

Hmm,
Naudin just posted an update:

http://jnaudin.free.fr/gegene/gegene05en.htm

and

https://www.youtube.com/watch?v=Iik6XnT2mE4


Seems he only gets now 91.4 % efficiency
when measuring the light intensity...

He says that he wants to do more tests.

I really would lke to see some scope shots of the involved waveforms from this.

Many thanks.

Regards, Stefan.

I know the induction heaters use a board full of electronics.  I wonder how much efficiency is lost there?   It seems it might be better to wind your own induction coil BIFILAR and skip the electronics and just use the Variac.  Measure output from the Variac to the input of the bifilar induction coil and I'll bet it gets much higher efficiency.   Since I've got a big Variac I may give this a try soon.

I can confirm that this kind of an air transformer (which it is in its essence) is 80 to 90 % efficient.
I did some rough tests today, here is one of them:
http://www.youtube.com/watch?v=-JSvSFugWwI
having some lab experience with frequencies and waves like these one I am pretty sure that this setup is less then 100% efficient.
The efficiency can be higher when the output circuit is put in RLC resonance, but I don't think it will be higher than 1.
(I am talking in Polish -- no time to translate yet, but I plan to.)

In the heater that Naudin opened to show, it appears that the large heat sink on the circuit board is right under the induction coil. Why does that sink not heat up from induction? It looks like it is right under.    

Strange.

Mags

Did you see he also showed AC voltage and current output?  I know that may not be the most accurate way but could it be that far off?   Isn't the induction heater a resistive load?   If so would it be possible to loop this?   The electronics in the induction heater might not like it but you could probably bypass them and just hook straight to the induction coil.  Or make your own.   Give it a jump start from the grid and have a relay flip it over to loop it?   Sounds easy enough to try.   Wouldn't that be a hoot if that's all it took....

Hi e2matrix,
Is an induction cooker a pulsed dc system? If it its maybe the output will not be pure sine, but pulsed dc?