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Author Topic: STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM  (Read 1211475 times)

Omnibus

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Re: STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM
« Reply #3105 on: May 19, 2010, 03:05:21 PM »
This is the schematic diagram with the three probes (the last data is taken with four probes). Here R1 = 1.0762Ohms is the resistor to measure the input current (voltage across that resistor divided by its resistance), R2 = 0.1192Ohms is the resistor used to measure output current, Rcoil1 = 65.2124Ohms is the resistance of the input coil while Rcoil2 = 0.5921Ohms is the resistance of the output coil.

In the screen images -- the yellow trace is always the input voltage across the input resistor (used to calculate the input current), the blue trace is the input voltage, the purple trace is the output voltage measured across the load (resistor, coil or resistor+coil, depends on the experiment) used to calculate the output current and when there's a green trace that's the output voltage.
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Omnibus

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Re: STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM
« Reply #3106 on: May 19, 2010, 04:00:38 PM »
See how the change of duty cycle by just 10% kills the effect. The results here are somewhere around the cutoff frequency and are taken in the "proper" way, that is, the voltage to be used to calculate the output current is measured across the 0.1192 resistor while the output voltage (to calculate the output power) is measured across the resistor and the load coil hooked up in series. Let me mention also that sine wave as well as triangular (jigsaw) input also kills the apparent OU effect. Should I post the Excel data as well?
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Omnibus

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Re: STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM
« Reply #3107 on: May 19, 2010, 04:08:53 PM »
This is expanded, to see the ringing and all:
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Omnibus

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Re: STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM
« Reply #3108 on: May 19, 2010, 04:35:24 PM »
I don't wanna clutter the thread with more pics so I'll say it in words -- the ostensible OU effect seems to be critically dependent on the pulse generator offset. It is maximum at a certain negative offset. Before and beyond that the effect decreases and even disappears.
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teslaalset

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Re: STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM
« Reply #3109 on: May 19, 2010, 05:24:51 PM »
Quote from: Omnibus on May 19, 2010, 04:35:24 PM
The ostensible OU effect seems to be critically dependent on the pulse generator offset. It is maximum at a certain negative offset. Before and beyond that the effect decreases and even disappears.

That is a remarkable finding.

I expect the optimum offset of the generator shifts if you use different resistor values as load to the secondary coil. If you have the time available, could you do that experiment?
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Omnibus

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Re: STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM
« Reply #3110 on: May 19, 2010, 05:31:48 PM »
I'll do that but first I'd like to check whether I'll be able to find that critical offset value for a lower frequency. I find the OU effect (or, what appears to be an OU effect) to be really sensitive to the offset value.

The main question is, of course, is this OU effect real but I think now that the output current is measured across an active resistor (by dividing that current by its resistance) we're somehow closer to an assertive answer because the inductance problem that was bothering me should be gone when measuring output current in this way.
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Omnibus

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Re: STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM
« Reply #3111 on: May 19, 2010, 06:52:14 PM »
@Omega_0,

The resistance of the RadioShack resistor is 0.47Ohms and not 47Ohms as I wrote earlier. Sorry about that. In fact, what I'm using is the measured value of 0.1192Ohms so that won't make any difference in the findings. Thanks for correcting this and the other error where I had the decimal point off by one place.
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Omnibus

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Re: STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM
« Reply #3112 on: May 20, 2010, 05:06:09 AM »
I was able to observe ostensible OU with a sine wave (skewed sine wave -- 10% duty cycle) as well. The instrument offset is -6.10 which amounts to -3.66V. The maximum is at 0.520V in square wave mode. The example here is at 80kHz. Unfortunately, I have to continue with the reduced mode in Excel 2003 because it turned out Excel 2007 cannot plot more than ~30,000 points. Anyway, here are the pics from the screen and the energy-time plot. If someone is interested I'll post the Excel data too. I should also mention that at these conditions the square and the jigsaw waves show worse OU results.
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Omnibus

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Re: STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM
« Reply #3113 on: May 20, 2010, 05:10:17 AM »
Now, with the above results we're getting closer to the affirmative OU claim because unlike the square-wave pulses with the steep fronts and higher order harmonics we see here much smoother traces. The inductance problems also seem to be fading away compared to the square-wave case.
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exnihiloest

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Re: STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM
« Reply #3114 on: May 20, 2010, 08:40:14 AM »
http://www.overunity.com/index.php?action=dlattach;topic=8411.0;attach=44825

This schematics is correct only in linear modes.
When a magnetic core is saturated as in Steorn motor, non linear resistances must be added in parallel with each L. The Steorn's measurement error is due to this simple fact.

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teslaalset

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Re: STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM
« Reply #3115 on: May 20, 2010, 01:00:45 PM »
Quote from: exnihiloest on May 20, 2010, 08:40:14 AM
http://www.overunity.com/index.php?action=dlattach;topic=8411.0;attach=44825

This schematics is correct only in linear modes.
When a magnetic core is saturated as in Steorn motor, non linear resistances must be added in parallel with each L. The Steorn's measurement error is due to this simple fact.

Good point.
What you are referring to are core losses. When passing through the B-H curve (using negative and positive input current) the surface of the B-H curve represents the loss per cycle.
The two figures below visualize this. The red areas represent the energy put into the coil, the blue area represent the energy returned by the coils. The difference is the core loss.

It was my understanding that Omnibus used only positive current input at first instance.
In such case the only extra losses besides the ohmic losses are due to viscosity, see the red area in the third picture below. For high frequencies they will be hardly noticeable because viscosity delay is much higher than the cycle time of the input.

In case of low frequencies, of course, these viscosity losses will also occur when full cycle the B-H curve (twice, one for the positive side, one for the negative side)
« Last Edit: May 20, 2010, 01:48:03 PM by teslaalset »
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Omnibus

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Re: STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM
« Reply #3116 on: May 20, 2010, 02:00:33 PM »
Quote from: teslaalset on May 20, 2010, 01:00:45 PM
Good point.
What you are referring to are core losses. When passing through the B-H curve (using negative and positive input current) the surface of the B-H curve represents the loss per cycle.
The two figures below visualize this. The red areas represent the energy put into the coil, the blue area represent the energy returned by the coils. The difference is the core loss.

It was my understanding that Omnibus used only positive current input at first instance.
In such case the only extra losses besides the ohmic losses are due to viscosity, see the red area in the third picture below. For high frequencies they will be hardly noticeable because viscosity delay is much higher than the cycle time of the input.

In case of low frequencies, of course, these viscosity losses will also occur when full cycle the B-H curve (twice, one for the positive side, one for the negative side)

See, core losses are over an above the Ohmic losses. Therefore, any observed OU based only on Ohmic losses, as in the discussed here case, would be just conservative -- the real OU effect will be greater.
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Omnibus

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Re: STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM
« Reply #3117 on: May 20, 2010, 02:15:08 PM »
@teslaalset,

At your request I changed the load active resistance to 0.0607Ohms (measured) by adding in parallel another 4 of the 0.47Ohm ceramic resistors. The apparent OU effect was slightly lower. However, adding another air coil in series with the original 0.1192Ohm ceramic resistor and the original air coil the OU effect shot way up. Now, here we may again think that the inductance is to blame for an error in the measurement, however, take a look at the schematic diagram for this measurement -- the output current is measured by dividing the voltage across the active resistance R2 while the output voltage is measured across both the resistor R2 and the air coil R3. Seems the measurement methodology is correct which gives further confidence in the reality of the observed effect. I'm attaching here the Excel file with the data from this 80kHz, 10% duty cycle, sine wave experiment taken at -3.66V (-6.10 pulse generator reading) offset.
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teslaalset

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Re: STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM
« Reply #3118 on: May 20, 2010, 02:22:49 PM »
Quote from: Omnibus on May 20, 2010, 02:00:33 PM
See, core losses are over an above the Ohmic losses. Therefore, any observed OU based only on Ohmic losses, as in the discussed here case, would be just conservative -- the real OU effect will be greater.

Some background of this can be found in a nice Texas Instruments document, page 5:
http://focus.ti.com/lit/ml/slup123/slup123.pdf
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Omnibus

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Re: STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM
« Reply #3119 on: May 20, 2010, 02:46:11 PM »
Quote from: teslaalset on May 20, 2010, 02:22:49 PM
Some background of this can be found in a nice Texas Instruments document, page 5:
http://focus.ti.com/lit/ml/slup123/slup123.pdf

Thanks for the link. It is my understanding that per cycle the energy that characterizes those losses is only given by the area enclosed within the hysteresis curve. In any event, like I said, those losses would give an even greater OU effect if included in the energy balance discussed here.
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