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Old 04-13-2012, 09:19 PM
Les_K Les_K is offline
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Join Date: Dec 2010
Posts: 190
Axle Generator far fetched thoughts and on......

Originally Posted by Ron Chase View Post


What is the reverse breakdown for the IRFP260 FET?

Thanks, Brent

Yay Brent. Start charging those batteries and begin thinking about building the second half of the wheel, the re-gauging motor.

The drain to source breakdown voltage for the IRFP260 is 200V but I wouldn't worry about that as it doesn't appear to have any relevance to the kind of cap dump function we are observing. We see dynamic charging at impossibly low current levels with all the different rated FET's we've tried so far so it has to be the RE flowing through the FET's that is doing the job regardless of what the breakdown voltage, etc. is of any particular FET. The RE doesn't care about voltage it justs wants to get to the negative pole of the battery. The higher negative potential of the cap see's the lower negative potential of the battery as positive and wants to get there anyway it can.

As far as how a FET is connected to the Cap - and the Batt - you just have to go with what works. The FET's inside SSR's often have other components associated with them such as the snubber diodes I mentioned earlier as well as how the FET was constructed all of which can affect whether it works with one connection scheme or another. The data sheet's often don't show this or even reveal the internal connections of the FET so trying to figure it all out can be maddening.

I'm just happy we've gotten to the point where we can begin building regauging motor's. Our big wheels are the perfect platform for experimenting with them.

Good Job!

Just a thought, I wonder if it might be the breakdown of the internal diode....

Ok, Here are some ideas I have been working with as far as the generators.
I had posted some of what I felt were important posts about the mag-Amp. And there is a lot there, I think the key is going to be changing the impedance at the right time as described in those posts. I don't think we need the motor function as much as we need a low RPM generator/alternator/G-field. I had thought about the axial flux alternator. There is a lot of good information on construction out there. But then I got to looking at coil shorting as Patrick knows. But I am still not sure.

I then began to take a simple approach. What can be done to increase the energy returned from a coil from it's initial input pulse without altering the input. we know that without magnets we can touch a coil to a battery and when removed get a large spike out.
Is there anything we can do to the coil that might increase the output significantly given the same input. This is where I thought about the magAmp effect and adding one wire with a small dc current oppisite to the other strands to alter the impedance. I thought about the fact that when a coil is energized in opposition to a the magnet it is in effect creating a super pole just as though you were pushing two magnets together. I was puzzling over that and tried to open a discussion elsewhere, Then I ran into this interesting video.
How to Build A TPU Pt. 3 - YouTube

I wonder if we made an SSG type generator based on this, and included the MagAmp.
It could run at any speed as it is just a matter of getting the impedance done correctly. Coil shorting, untwisted litz(as he calls it) and mag-amp. I don't know just goofy thinking here.....

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