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Author Topic: E-Orbo replications  (Read 20533 times)

Omega_0

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E-Orbo replications
« on: May 09, 2010, 03:30:12 PM »
Starting a new thread to post my own Eorbo experiments, as the original thread is already too big now. I will also post the replication attempts of others who are not on this forum (yet), as and when I get any news about them.

So update here :
Made some changes in the design. The magnets are now in NN config and are placed underneath the rotor more securely. Now even if they get loose and fly off, the edge of the rotor will stop them from coming out.
The bearing in on top now and is better centered with no tilt.
All these justify a version change, so lets call it ver 0.3.

As expected the cemf is gone with NN config (scope shot below). Now the funny thing is, there is some cemf (in my case 10 mV at 200RPM) when you measure it directly across individual coils, by spinning the rotor by hand. It does not become zero however precisely I position the coils. But when two coils are connected in series, in such a way that their cemfs cancel out, it becomes almost zero. Connecting the coils in aiding mode obviously increases the cemf 2x.

So a good lesson learnt is, always connect the coils in opposing way.

Now there is some trade off here, NN mode means less attraction which means less RPM, so my speed at the same current has reduced by half. This is not desirable, so I will try to go back to SN mode again and see if there is any way to reduce the cemf.


Omega_0

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Re: E-Orbo replications
« Reply #2 on: May 10, 2010, 10:18:28 PM »
Got some decent speed improvements with air gap and reed optimizations. Now its running above 500 RPM. Unfortunately the cemf shows up at high speeds.

I loosely placed two pickup coils above the rotor, both with 500 turns and 25 mm dia. These produced about 3.1 V peak to peak AC at open circuit. Scopeshot is below with some data. (Purple trace is pickup and orange one is input pulses. Note that the pulse cuts off just after rise time, the inductance is too high)

I have 4 such coils, need some hardware changes to mount them. I can't capture the scope data, its software needs upgrade, so must wait for detailed calculations till the upgrade is available.


Omega_0

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Re: E-Orbo replications
« Reply #4 on: June 19, 2010, 09:17:12 PM »
Update: 0.6
Some important progress was made.
Good news 1 : Got hold of 8 medium-high Mu cores of material T38. This version has just one of these with 80-100 turns of 20 AWG and its rotating at 130 RPM. Rotor is same old one.
Good new 2 : SDK for my USB scope was released and I managed to modify some example code to dump the data in CSV format. At this time it cannot dump data sampled at more than 20 KS/s, so the very very fine details of waveform are not there. Anyway the data is here :

Captured data in Excel 2007 format:
http://www.overunity.com/index.php?action=downloads;sa=view;down=393

Good news 3: The Ein plot is very much similar to Steorn's demo-1, with similar "mountain ranges" and the peculiar negative going energy. This is a good verification that steorn did not play any tricks during the demo, as many skeptics still believe. I think no one else has published such plot before this. So its important one.
The current (Iin) plot shows no CEMF, finally. The Vin plot shows the flyback after the pulse ends. The spikes at the start of pulse can be due to reed switching on, but I'm not so sure about that. It should not be there.
The IV-I^2R (non-joule energy) is mostly near ZERO. Almost no power is transferred to the rotor (going 130 RPM on cheap bearings).

Omega_0

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Re: E-Orbo replications
« Reply #5 on: June 19, 2010, 09:32:31 PM »
Setup is shown below. Vin was measured across the coil+sensing resistor Rs. Iin was measured across Rs, which is 1 ohm carbon resistor, not so precise, but I have no high end sensing resistors at the moment.
The reason I included Rs to measure voltage across the coil, was that the RDC of the coil is tiny and so is the voltage drop across it, and my scope captures just noise at such low values. Anyway Rs was included in the calculations as a part of RDC. So Rin = RDC + Rs.

I have no precision meter to measure the Rin, so I used scope itself and the Rin is an average of 800 measurements of V/I at the steady state part of the pulse.
Rin must be measured to at least 1/1000th of the ohm. Even small deviations of 0.001 ohm changes the Ein landscape totally. This is the critical part.

So things are not very accurate at this stage but everything is going towards a positive direction, so I'm happy.


Omega_0

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Re: E-Orbo replications
« Reply #6 on: June 19, 2010, 11:04:30 PM »
More about material T38.
I'm attaching here the specs of toroids that I'm using in current version and also of the alloy T38 (which I guess is MnZn Ferrite). Its EPCOS part no. B64290L618X38, dimensions : 25.3X14.8X10 coated with blue epoxy.

Its Mu_i is 10000 and H(sat) is around 100 A/m from the datasheet. So from
H = N*I/lc
where N is number of turns, I is current and lc is flux path length, we can get the saturation current for say, 100 turns of coil:

100 = 100*Isat/lc
lc = pi*( 25.3+14.8 )/2 = 63 mm = 0.063 m
Isat = 100*0.063/100 = 63 mA

Or say you want Isat = 1 Amp, which gives N = 6.3 or 7 turns. So you would expect that just 7 turns at 1 Amp or 100 turns at 63 mA shall saturate the core completely and the rotor will not be attracted to the core at all. Sounds like free lunch.....

But, don't be surprised if the core refuses to follow the text book in presence of a strong neo. In my case the coil is taking max 2.8 Amps@100 turns and the core still shows strong attraction for the magnets ! I have no idea why this is.......... anyone knows ???? Isn't the core supposed to "disappear" for magnets when saturated ?

Either the formula I'm using is wrong or something else is happening here. This is an unknown land for me.


Omnibus

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Re: E-Orbo replications
« Reply #7 on: June 20, 2010, 12:01:58 AM »
@Omega_0,

Good job. I'll focus on this as my first post here:

Quote
But, don't be surprised if the core refuses to follow the text book in presence of a strong neo. In my case the coil is taking max 2.8 Amps@100 turns and the core still shows strong attraction for the magnets ! I have no idea why this is.......... anyone knows ???? Isn't the core supposed to "disappear" for magnets when saturated ?

You know, I had the same problem and I never resolved it. The only thing I could achieve is what Naudin is showing in his video--when using a ceramic magnet. Could never achieve it with neos. As you know my approach is to use a pulse generator rather than the way Steorn are doing it and I blamed my pulse generator for that--the max current that it can supply is on the order of several hundred mA only. If you wanna get pulse generator capable of supplying amps you have to part with probably ten or twenty grand. Tried it with a battery and a relay and so on but never got it to work. Hope you'll be more successful because, as far as I understand, you're at least capable of powering it properly. Luckily, somehow I got into the research I'm doing right now and got away from that nightmare. I would still be interested in a pulse motor but only as a curiosity. 

Omnibus

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Re: E-Orbo replications
« Reply #8 on: June 20, 2010, 12:07:21 AM »
As for the current measurements, the metal-oxide 10Ohm resistors from RadioShack as shunts are just fine. That was confirmed with my current probe. Recall @LarryC was insisting on that (I had to verify it, though). So, you're all set on that, I think. Stay away from industrial standard shunts if you're working at high frequencies as well as, of course, from wound precision resistors. All there develop inductance voltage and are no good as my current probe indicated.

Omnibus

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Re: E-Orbo replications
« Reply #9 on: June 20, 2010, 12:09:29 AM »
Quote
I think no one else has published such plot before this. So its important one.

I agree. Keep up the good work.

Omega_0

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Re: E-Orbo replications
« Reply #10 on: June 20, 2010, 09:44:12 AM »
What do you think about the calculations ?
It will be good if I get a confirmation that everything is correct in that sheet. I'm thinking about investing some more in the hardware and want to make sure I'm not doing any stupid mistakes.

Omnibus

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Re: E-Orbo replications
« Reply #11 on: June 20, 2010, 01:25:59 PM »
Can't unzip the file with the Excel data. The error message says:

'The archive is either in unknown format or damaged'

However, in view of the importance of Rin I don't think you should measure it by using the scope. Can't you measure it independently? Otherwise, I think you should measure the input voltage both across RDC and Rs, as you do.

Omega_0

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Re: E-Orbo replications
« Reply #12 on: June 20, 2010, 06:29:31 PM »
Can't unzip the file with the Excel data. The error message says:

'The archive is either in unknown format or damaged'

However, in view of the importance of Rin I don't think you should measure it by using the scope. Can't you measure it independently? Otherwise, I think you should measure the input voltage both across RDC and Rs, as you do.

May be the download got interrupted. Anyway uploaded again in rar format
http://www.overunity.com/index.php?action=downloads;sa=view;down=394

Don't have a precision meter at this time. Need to invest in one. Scope is giving me readings to 12 decimal places. But the current values assume that Rs is exactly 1 ohm and any error in it will carry over to Rin obviously.

Omnibus

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Re: E-Orbo replications
« Reply #13 on: June 20, 2010, 06:34:48 PM »
Have to go now but will take a look at it when I get back. You're quite right about that resistance. Can't we do something to have your rig measured with the instruments I have? I'm in Massachusetts right now. Where are you located?

Omega_0

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Re: E-Orbo replications
« Reply #14 on: June 20, 2010, 08:27:07 PM »
That would be cool but I'm not in US so may not be possible.
Anyway I've decided to invest some more now and a high end meter and scope will be available hopefully soon for confirming these measurements.

Already started search for a few meters of high temperature superconducting wire. These are within reach but the equipment to cool it down to those "high" temperatures will be costly. Well, that's my future plan. Right now need to wind all 8 cores and build a new rig to mount them all........