Variables of RPM

[Howard Wetsman]

Obviously the construction (coils, axle, etc) will determine a large part of RPM on a rotary SG, but I've been interested in looking at other variables given the same build. I have a 10 coiler that I've described before and have been noting down some variables during the last 6 runs since I took out all the switches to the coils and ran them directly. I notice that the machine runs slower when it's colder, slower the longer it runs (affected by battery's ability to accept charge?), may change by time of day, and I'm wondering, but have no data about, tidal forces. Has anyone here done an analysis or any thoughts as how to proceed in order to rule out the various variables?
thanks
h

[Howard Wetsman]

Here's the model I have from my data that explains 98% of the variance. DeltaV is the difference between the charge voltage at the time of measurement and the starting charge voltage, so essentially a measure of time as well as a measure of the fullness of the charge battery.
h

[Howard Wetsman]

Sorry, hopefully this is a better picture

[John_Koorn]

Hi Howard,

Interesting observations. I'm not sure I fully understand what the DeltaV means, however it is well known that the speed of the rotor will increase as the charge battery voltage rises. This is due to the change of impedance in the battery under charge.

John Bedini explained in EFTV DVD #2 that under certain conditions the rotor speed will also change, for example during night time or under a full moon. I have no solid data to verify this though.

John K.

[Howard Wetsman]

John,
I'm seeing almost the opposite. The rotor slows down as the charge voltage goes up and with just these few data points I don't see anything statistically significant, but it seems to slow down at night. No data on full moon phase yet.
DeltaV is the difference between the voltage of the charge battery at measurement from the voltage of the charge battery at rest before charge run, basically the rise in voltage during the run to that point.
h

[Kamen]

Howard,

I am also seeing the rotor RPM decreasing but that may be because the voltage of the primary battery also drops. At least that's what my explanation. Ambient temperature also affects the way a battery receives a charge and may be affecting impedance so that may play a role as John K suggested. Thank you for sharing your research I have been wondering about that as well.

Kamen

[Howard Wetsman]

Howard,

I am also seeing the rotor RPM decreasing but that may be because the voltage of the primary battery also drops. At least that's what my explanation. Ambient temperature also affects the way a battery receives a charge and may be affecting impedance so that may play a role as John K suggested. Thank you for sharing your research I have been wondering about that as well.

Kamen

Kamen,
I am wondering and it seems chicken/egg about rotor RPM and primary draw. Does RPM go down because the battery has a lower voltage and can't put out as much or is the draw lower because the rotor is slowing. I had been assuming the draw is lower because the rotor has slowed, and that the rotor speed is determined but the physical set up of the system and environmental factors. Not sure why the voltage of the primary would effect the dipole created at the coil, but I might not be fully understanding the physics. I'm trying to get a handle on cause and effect. That's why I'm doing this.
thanks
h

[BobZilla]

Hi Howard,
You seem to be very methodical in testing. I tell you something else to try. Align your machine's magnets on the north/south field of the earth. Most people don't think about this alignment.

[Howard Wetsman]

Bob,
That's something I didn't think about. It's currently almost directly east/west. I positioned it there as it sits on my workbench oriented so that if it threw a magnet it would go lengthwise down the bench and not at me standing there. But I can turn it and put it at the end of the bench next to a wall and just stay in front of the axis of rotation.
Thanks for the idea.
h

[Howard Wetsman]

I now have over 100 observations at various times over 12 runs. 11 runs were with 10 coils and the last run I've put one coil on a comparator charging a second battery (that's not doing well, but that's another thread). Any way, the number of coils is an obvious variable, but using only the 10 coil runs, here's what I've found. 92% of the variance of RPM is explained by a model containing minutes in the run and temp at the time of measurement (446.09+.011*minutes+1.43*temp). What's interesting is that the same factors explain 97% of the measured draw from the primary battery (drawAmps = 1608.76+46.8*temp-.035*minutes).
The situation is that I'm charging up a 214AH battery bank using a 215AH battery bank and can complete the run with the single charge of the primary. That's the best I've ever done so far. In doing COP calculations, I'm noticing that we use a single number for primary draw, but draw falls as the run goes on, so I'm thinking we should use a calculation of an average draw over the time of the run with a model such as that above. Anyone have any thoughts about that?
h

[BobZilla]

I know what your saying about the primary falling and making it hard to get a true number. I have mentioned that before too.

Tom posted a watts meter of some sort in another post and it looked like it could be useful in measuring exactly what was used from a primary. What I do not know is if it pulls energy from the circuit which would throw of the readings, also didn't see what kind of power it can handle and measure. Maybe Tom will see this and can elaborate on that thing, I have never used one.

Howard some of your numbers got fudged by the forum. I have found that when you use percent symbols and fractions it mucks it up so I usually write it out. Check your post and you will see what I mean.

[Tom C]

This is what I have:
http://www.powerwerx.com/digital-met...owerpoles.html

cheaper here

http://www.hobbyking.com/hobbyking/s..._Analyzer.html

130 amps peak 60 volts max

it pulls almost nothing, AND you can run an outboard power supply so there is zero draw from the primary battery.

Tom C

[Howard Wetsman]

I know what your saying about the primary falling and making it hard to get a true number. I have mentioned that before too.

Tom posted a watts meter of some sort in another post and it looked like it could be useful in measuring exactly what was used from a primary. What I do not know is if it pulls energy from the circuit which would throw of the readings, also didn't see what kind of power it can handle and measure. Maybe Tom will see this and can elaborate on that thing, I have never used one.

Howard some of your numbers got fudged by the forum. I have found that when you use percent symbols and fractions it mucks it up so I usually write it out. Check your post and you will see what I mean.

Bob,
You're right. Those were percent signs. Thanks for picking that up.
h

[Martin B]

Here's a review of the Turnigy vs the GT Power vs the Watts Up Power Meter
http://www.youtube.com/watch?v=Lxv9Rozs774
I've never used any of them.

Martin B

[Tom C]

Just orderd a pair of the turnigy ones to see how they compare with my watts up meters.

Tom C