Over Unity NOT Achieved!!!

[wattsup]

@oouthere

Your Quote
PM: 4.7 amps @ 121VAC =568.7 watts
Alternator without load:  398VAC @ 7.5 amps @ 116.2hz = 2985 watts
End Quote

If the alt is wired for 230 VAC and you are producing 398 VAC, then you are turning to fast and your alt may be producing more harmonics.

This is one reason I recommended putting a reostat on the PM. Just a slight decrease in run current may make all the difference. Your alt voltage will drop but amperage will rise because the rotor drag will have enough time to charge the stator.

Although the RV directive on page 31 gives alternatives when PM rmp is higher than the alt, I would try to sync the rpms with a reostat and see the effect. Just make sure you start the PM with reostat shorted first then put it online. It will heat up a bit but for short periods it is a good and cheap way to try this.

[gyulasun]

Well,  I'm really confused at this point and will need to think abit.  Here are readings from a quick test, no great tuning just something to compare the DVM to the o'scope.

PM: 4.7 amps @ 121VAC

Alternator without load:  398VAC @ 7.5 amps @ 116.2hz

TRUE FULL BEAUTIFUL SINE WAVES

I want to believe and the meters say it is there but this is just out right strange.

Rich

Hi Rich,

I am not sure what you find strange?  The fact you see pure sinewaves across your tank LC circuit?  (because the self inductance of your alternator windings and your cap bank capacitor constitute a resonant LC circuit and the resonant frequency of the LC circuit is 116Hz as you wrote).  In a resonant LC circuit the waveforms are always sinewaves.
Or you find it strange the frequency is 116Hz and your DVM is well within ballpark?

The oscilloscope shows you the peak to peak value of the voltage across your resonant circuit and your DVM shows you the effective (RMS) value of the voltage. So if you have standard 120V AC mains voltage, you must see 120V directly on your DVM (of course +/- a few volts due to peak hours or off peak hours) and if you watch the same mains voltage on your scope (use 1:1 safety transformer if your scope input ground needs it!) then you must see 2.82 times 120V peak to peak amplitude on your scope display, right?

No need for other theory this time to explain what you measure.

The current of 7.5A is maximum then what can flow inside your alternator resonant circuit and this is fully governed by the windings copper loss and to some extent the iron loss.

If you multiply your 116.2Hz by 60 seconds you get the RPM your alternator's shaft rotates.
What value of capacitor did you happen to use to arrive at 116.2Hz, if I may ask?
Now if I may suggest to look resonant current higher than 7.5A by changing somehow the PM's RPM and see if the alternator's windings are happy with higher (or lower) frequencies? You can see this by watching the resonant current at the alternator how it changes for the RPM changes. Of course you have to readjust the cap bank to reconstitute resonance for each change in RPM.

Regards
Gyula

[gyulasun]

Hi Rich,

There is one more thing that occured to me to ease finding the best resonant state (which would mean the highest circulating current in your alternator or in any other motor you assign for alternator). It is using an electric hand drill with variable speed and you could connect directly the drill head to the shaft of the alternator and control the rotation speed. of course the drill should be fixed somehow to a base where your motors are.

This is only to explore relatively quickly how the changing RPMs will change resonant current, no need for reostat. Perhaps next door neighbours can lend you a variable speed drill if you happen to not have... 

Gyula

[oouthere]

Well,  I'm really confused at this point and will need to think abit.  Here are readings from a quick test, no great tuning just something to compare the DVM to the o'scope.

PM: 4.7 amps @ 121VAC

Alternator without load:  398VAC @ 7.5 amps @ 116.2hz

TRUE FULL BEAUTIFUL SINE WAVES

I want to believe and the meters say it is there but this is just out right strange.

Rich

Hi Rich,

I am not sure what you find strange?  The fact you see pure sinewaves across your tank LC circuit?  (because the self inductance of your alternator windings and your cap bank capacitor constitute a resonant LC circuit and the resonant frequency of the LC circuit is 116Hz as you wrote).  In a resonant LC circuit the waveforms are always sinewaves.
Or you find it strange the frequency is 116Hz and your DVM is well within ballpark?

The oscilloscope shows you the peak to peak value of the voltage across your resonant circuit and your DVM shows you the effective (RMS) value of the voltage. So if you have standard 120V AC mains voltage, you must see 120V directly on your DVM (of course +/- a few volts due to peak hours or off peak hours) and if you watch the same mains voltage on your scope (use 1:1 safety transformer if your scope input ground needs it!) then you must see 2.82 times 120V peak to peak amplitude on your scope display, right?

No need for other theory this time to explain what you measure.

The current of 7.5A is maximum then what can flow inside your alternator resonant circuit and this is fully governed by the windings copper loss and to some extent the iron loss.

If you multiply your 116.2Hz by 60 seconds you get the RPM your alternator's shaft rotates.
What value of capacitor did you happen to use to arrive at 116.2Hz, if I may ask?
Now if I may suggest to look resonant current higher than 7.5A by changing somehow the PM's RPM and see if the alternator's windings are happy with higher (or lower) frequencies? You can see this by watching the resonant current at the alternator how it changes for the RPM changes. Of course you have to readjust the cap bank to reconstitute resonance for each change in RPM.

Regards
Gyula

What I find strange is 178VAC does not burn-out a 120VAC bulb plus it is not burning at full brightness.  And, 270VAC will not cause two 120VAC series bulbs to glow at full brightness.  To me, this is indicative of a static voltage riding the current producing sine wave and the static voltage measurement is not dropping out because there is no load on it to cause it to drop.  IMO, since there is less current in the rotor to drive the static potential under load the wave will always be symetrical and appear as a full sine wave.

Best guess theory and it would explain everything I've seen thus far for my own research and the others I've seen. 

Wattsup, the motor is not at a constant rpm as it does change some.  The higher the rpm the higher the indicated voltage.  Tuning is pretty easy actually.  I can load down the PM with more capacitance, show a voltage surge in the alternator, but after a few seconds it also lowers the indicated voltage after the initial mechanically induced stored power from the weight of the rotor is drained off (kinetic energy rather...).  The tuning is simply finding the best cap for the current load and the rpms will simply fall where they do.

Rich

[gyulasun]

What I find strange is 178VAC does not burn-out a 120VAC bulb plus it is not burning at full brightness.  And, 270VAC will not cause two 120VAC series bulbs to glow at full brightness. 

Hi Rich,

The 178V AC is measured across the 120V bulb when inserted or measured across the capacitor when the bulb inserted?  Please make it clear.
Thanks
Gyula