Hi everyone,
I made a new video to try to explain to the best of my understanding what makes this circuit work.
You can watch the video if you want but it's kind of boring as I'm not doing all that much.
Link to Video:
http://www.youtube.com/watch?v=N8BehANEVUoHere is how I understand it at this time.
A magnet is needed, a ferrite core seems to be important also but what I think is very important is INDUCTANCE. This is what I mostly say in the above video, so you can watch it if you want or just read this.
Lets say we have a toroid or an open end FERRITE core coil an its inductance is 1 Henry. We know by adding a permanent magnet to the core the coils inductance will drop depending on the strength of the magnet or the saturation point of the core.
I'm quite sure the effect of returned energy works best with the strongest magnet! BUT as I stated above if the magnet is strong you may be left with next to no inductance. The 1 Henry coil you start with can easily go down to 10mH (Milli Henry)
What maybe happening when a permanent magnet (PM) is added to a coils core is when the coil is energized its electromagnetic field pushes against the permanent magnet field and once the coil is switched off the PM flux bounces back. This is where the return energy is coming from.
Now if we think about it, then we want the most powerful bounce back. So we want a strong magnet!... BUT a strong magnet will reduce your inductance next to nothing as stated above!... who cares, just build it right!... Wrong!... Inductance is what your coil needs to be able to create a strong Electromagnetic field to push against those strong magnets. So if you're left with only 10mH your coil will need a high voltage with much current to be able to create a strong enough push against the PM.
Now for the other problem. If you wind a Mega Inductance coil that reaches the 10 Henry mark it will need much wire length... who cares, just build it right!... Wrong!...wire length give resistance and resistance gives energy losses and not to mention coil reaction time (electromagnetic field building time).
So all these things need to be considered to get the right balance. So what do we do?
I have found and been trying to demonstrate and share since my ORBO replication that if you wind 2 coils in perfect half moons on a ferrite core the Inductance is close to double then the standard single coil toroid. Would this not be a coil design to consider for the above project?... hum... let's see, twice the inductance and no extra resistance then the standard coil. Sounds good to me! but you decide.
I built mine with 30 AWG which has much resistance and ended with only 6.9 Ohms and over 1 Henry inductance. I would recommend using 20 AWG or a thicker wire if your cores are large enough and wind it to 2 Henry or more if you can. But like I said many things need to be considered, like the total coil resistance, coil reactance time, PM strength to core saturation limit, the right inductance to push the pm field and also the right inductance to bring the coil to resonance. Yes! Resonance, another area to consider and important if you want the coil to be efficient.
Resonance is what's going on when I've been demonstrating the energy going back to the source. This is why I started this topic to bring this possibility to light. JLN has not found this effect yet, as I think his residual inductance is very small with the magnets used. He would need a much high frequency then he's been using to see it. However I do agree with him that the energy comes from magnets push back when coil is switched off. The other thing that is needed is a MOSFET as switch to see the resonance effect unless you add capacitance. It appears that the built in capacitance of a mosfet is what is most likely bringing the coil to resonance. I tried it with a regular transistor and nothing happens.
The other interesting finding I have is, the mosfet can self oscillate (switch) itself IF the right combination of inductance between the main coil and pulse coil (added between gate & source) as long as the circuit is tuned to the resonance range. By using a 3vdc feed, my dual coil toroid, IRF640 and tuning coil have achieved resonance to any frequency I want between 5KHz to 50KHz WITHOUT the use of capacitors. Many of the frequency Inductance values have been documented and someone more knowledgeable than me is working out a formula that will be shared with all.
The above is the description to the best of my ability at this time of what is going on in the circuit at this time.
Hope this helps some to better understanding what I've been trying to share.
Luc
Author
Topic: Self running coil? (Read 83106 times)
