COP 17 Heater | Rosemary Ainslie

[Aaron]

other mosfets with repetitive avalance capability

There appears to me a whole mess of hexfets that have the Repetitive Avalanche Rating.

Google search for: "repetitive avalanche rated" hexfet

Perhaps someone that is an expert in data sheets can look at the specs on different ones and see if there are any that are truly comparable to the IRFPG50?

Might make it easier to get a lot of replications off the ground. I still think everyone should try the IRFPG50 first but if it is hard to get, then one with at least the same capability should be used instead of any 'ol mosfet.

[Aaron]

testing

Hi Rosemary,

There can still be successful replications.

There is a LOT of innovative and brilliant experimenters here and it will be exciting to see all the different variations and hybrids that come out of this. I can see unlimited applications across the board.

Also, with the properties of this mosfet, I think it could take all the joule thief type circuits to light lights, etc... to the next level of efficiency. This is what we all needed to know.

Imhotep, Slayer, Lidmotor, and others can probably show something along those lines pretty quick.

Anyway, as far as your particular circuit, it is only a matter time until all the tuning protocols are locked in solid so someone can go to the bench and make it work on the first try. As long as the concepts in tuning are known, then the type of talented experimenters here can get great success.

I'll definitely say that there are a lot of things in that scope shot that are only visible if zooming way deep into it. In some, there are ringing inside ringing inside ringing. Like a fractal.

Also, there are probably enough people here to get a good feel on the relationship between the duty cycle and frequency for different inductive resistors as well as gate tuning.

Right now, I have about a dozen different inductive resistors.

The physical size of these that I'm running through multiple tests have a physical size from about 8cm long and 1cm diameter up to 27cm long and 3cm in diamter (that one is a monster 10 ohm 200w clarostat with 86uH).

Inductances are from a few uH's up to 86uH for the 10 ohms and up to several hundred uH for the others.

Even with the much larger inductances, yours was 8.64uH, I don't see much of a problem with switching speed on them. Open hollow core, these things have no problems from what I see so far.

I checked the specs on your scope and it appears it is designed to handle very complex wave forms. I'm sure someone with experience there can adress the reality of that. Fluke 199C.

I have put a ferrite rod in some all the way and partially, and it just seems t dampen everything across the board.

Anyway, I've run the short tests of 10~30 minutes to just check the properties of little changes here and there up to 30 hour tests. Basically, I have been runing tests 24 hours a day 7 days a week since I posted my very first video of the SG hybrid oscillator with a resistor in series (until I got my mosfets from Hong Kong.

I'm now using for the first time my batteries that match your exactly. Two 12v 20ah batteries. Mine are sealed gel cells in my lawnmower. They are in perfect shape and I keep them in good shape with my 1AU Universal Bedini charger. There is no better charger in the world to ensure that the batteries are in tip top shape for each test.

I would recommend that everyone read the last several posts you did in the model thread:
Specifially post 32 and up:
http://www.energeticforum.com/renewa...eld-model.html

I think it is important to see your point of view on the current. Especially since your theory predicted what the circuit is doing or is supposed to do. There are VERY FEW people that can say that their idea predicted something that works when they build it... in non-classical theory.

[witsend]

Thank Peter. Sounds really exciting. But what I was asking was what do we do with those who replicate but without storage scopes? Can you sort out test parameters with batteries? Something?

[Peter Lindemann]

Aaron's Set-up

Maybe Aaron or someone can set up a system of testing that is OK'ish - with battery draw down rates or some such? Or perhaps we can persuade Peter to put his oar in here. It should be possible. And all input so much appreciated.

Rosemary,

Currently, my "oar in the water" here looks like this. Once Aaron gets his test circuit completely set-up, (this is essentially done, already, he's just waiting for the scope to arrive) I'll go over to his house and help him develop the test procedure and data collection. Once Aaron's set-up is actually a "duplicate" of your original, a wide variety of tests can be performed.

Of course, the first test is to replicate your results, to the best of our ability, and report the results of that. The next thing to do is to make sure Aaron gets all the credit for the replication, otherwise he might stop giving me a cold beer when I come over to visit him!

Once the test set-up is working properly, a second one will be built to duplicate the result again, and be used as a "test stand" to run other experiments without dismantling the original replication model. Using the second model, different MOSFETs and other transistors can be put in the circuit and compared for performance. Also, we can try other variations of the energy re-cycling process, including the method that uses the front-end capacitor and/or simpler resonant methods. The other direction to go is to scale the process up to produce "industrially significant" amounts of heat.

It is just a matter of taking things step-by-step.

Peter

PS.. Rosemary, next time you throw me an oar, make it two, so I don't just end up paddling around in circles!

[gyula]

GYULA, thanks for the specs, i appreciate the input :-)

i guess my main question was........ how much "oomph" is the flyback worth....in comparison to the "oomph" that created it in the first place?.

ie - not just comaring voltage to voltage....... but total ooomph IN(initial pulse )....to total oomph OUT (the flyback)

an example....... if i send a pulse in.....12V, 100Ma, for say...... 1/10th of s second....... then..i store the flyback in a cap....

now....i could have taken that initial pulse......and used it instead to light a 12v bulb rated at 100mA......and i could have lit that bulb for 1/10th of a second...... if i now take the cap.....and put the bulb across it, how long will it light for?..... 90% of 1/10th of a second?......80% of 1/10th of a second?

Hi David,

Unfortunately the only correct answer I can give to your above question is to find a practical setup and test it (using NOT a bulb for the load but a pure resistor, bulbs are nonlinear resistors and further complicate the life of innocent experimenters..., lol). I have not done such comparison in practice you describe.

What I presently think is that in your hypotetical example, the bulb will light for about 90% of the 1/10th of a second, I hope I am not much mistaken...

(Actually, what have you done in your example above? You converted battery energy or a power supply energy into magnetic energy by switching, and you captured the magnetic energy in a capacitor and you have received electrical energy stored in the cap. The very moment you wish to use this stored energy in a load like a bulb or a resistor, then in my present understanding, in your example setup you are allowed to use about the 90% of the energy you have taken out before from the battery by the switching.)


I have found a good paper on pulse power by Kanarev, see here:
Pulse Power

and also a good link on pulse power calculation (in connection of radar but this is not a problem here):
Pulse energy content

If you try to digest those few pages, you will have a better look into the real energy content of pulses.

Rgds, Gyula