Self accelerating reed switch magnet spinner.

[MileHigh]

TK:

So now that you have done rundowns it will be interesting to see what happens next.  I am assuming that you have a system to measure the moment of inertia and the spin-down.

Measuring the power required to maintain the rotor at a given RPM is not easy.  Note that you have the sensor coil and the op-amp output giving you ticks as the rotor spins down.  And you could get some ticks if you had a thread wrapped around the rotor with a dropping weight and a pulley wheel.

I assume an Arduino wizard could write a program to crunch the data. I can only think of an old-school way to record the data.  Something like condition the signal so your sound card input could record the ticks.  You record a wav file and there is your raw data.  Then there is a bunch of processing steps to get your information.  I wonder if out there in cyberspace if some Good Samaratin has written an Arduino or other program to do that.

MileHigh

[synchro1]

Imagine the gain in efficiency the MHOP circuit's duty cycle reduction timing would bring to Art Porter's GAP technology.

[TinselKoala]

I guess it all depends on what you mean by "useful". It makes a killer power supply for my neon ring oscillators.


Rotorless MHOP, the motor with no moving parts:

http://www.youtube.com/watch?v=z0sjqoshznU

[TinselKoala]

TK:

So now that you have done rundowns it will be interesting to see what happens next.  I am assuming that you have a system to measure the moment of inertia and the spin-down.

I'll eventually calculate the MoI based on the weights and dimensions of the parts and the geometry. Without a paper chart recorder, the spin-down is best measured by taking a video (for the time stamps) of the rotor alongside the Arduino tachometer display (for the second-by-second RPM value).

Measuring the power required to maintain the rotor at a given RPM is not easy.  Note that you have the sensor coil and the op-amp output giving you ticks as the rotor spins down.  And you could get some ticks if you had a thread wrapped around the rotor with a dropping weight and a pulley wheel.

I think you are making it far more complicated than it really is. The MoI and rundown data will allow the calculation of rotor mechanical power dissipation at any RPM in the operating range. The instantaneous slope of the unpowered rundown curve is the power dissipation at that instantaneous RPM (when the correct units are used.)

I assume an Arduino wizard could write a program to crunch the data. I can only think of an old-school way to record the data.  Something like condition the signal so your sound card input could record the ticks.  You record a wav file and there is your raw data.  Then there is a bunch of processing steps to get your information.  I wonder if out there in cyberspace if some Good Samaratin has written an Arduino or other program to do that.

MileHigh

Programming the Arduino tachometer to write RPM values to a file every second, say, and report it to the controlling computer over the serial line is trivial. A nice rundown curve can be generated this way nearly automatically and in realtime, by sending the data to a "processing" sketch. (What a stupid name for a programming suite. Am I talking about just processing some data, or using the program named "processing" to process the data? Dumb choice of names.)
http://processing.org/

[TinselKoala]

Imagine the gain in efficiency the MHOP circuit's duty cycle reduction timing would bring to Art Porter's GAP technology.

OK, I'll try really hard to do that.

It appears that Art Porter has invented the linear alternator.