Muller Dynamo

[neptune]

Details . Core , mild steel about 10 mm diameter by 10 cms long . 125 turns of wire in a single layer , covering about 80% of core . Wire is about 28 guage SWG . Resistance about 0.4 ohms . Straight core , not horseshoe shaped .

[nul-points]

Details . Core , mild steel about 10 mm diameter by 10 cms long . 125 turns of wire in a single layer , covering about 80% of core . Wire is about 28 guage SWG . Resistance about 0.4 ohms . Straight core , not horseshoe shaped .

ok... more questions 

are all the e/ms single layer (just alternate, etc, windings)?

are the nails small (eg. tack size), or large (eg. floorboard nail size)?

if they're large, can you get better differentiation between bi & quadrifilar by using small nails for the 'pick-up' test?

did the source info comment on any diffs between long narrow coils & short wide coils?

thanks!

[Jdo300]

Hello All,

After the first few videos I did yesterday, I performed the same tests on the motor again only this time, the generator coils were connected in series adding rather than series canceling.

The results I obtained were quite fascinating to say the least, though the general behavior was the same as the series canceling configuration. Also as my previous results showed, the parallel configuration was the only one that gave me acceleration under load. But this time, rather than a 100RPM increase in speed, I saw over 2000RPM increase.

However, as myself and some people mentioned in previous posts, having the circuit wired in parallel with the capacitor does present a constant load to the coil until the coil is shorted. In the video you will see that the motor (without the capacitor in the circuit at all), will speed up to about 3770 RPMs and when I short the output on the DC side, the motor slows down. When adding the capacitor in parallel, the motor slows down to about 1900 RPMs or so and stays there (without the short). Once shorted, the motor speeds back up to about 3400RPMs (check the video for exact numbers, I'm going from my memory at the moment).

However, the output power is dramatically different with and without the capacitor! Without it, the max output votlage across the capacitor was about 30VDC. However, with the capacitor in the circuit, the output voltage pegged my meter at over 60V coming out of the system. Also when shorting the output, the power available appears to be much, much greater (plus the added bonus of the acceleration of the rotor).

What it appears is that the best way to extract energy from this system will be to use the coil shorting technique to convert the high current into high votlage. But using a wide duty-cycle pulse so that the coil remains in the shorted state most of the time to reduce drag on the motor.

Here is the link to the video. Please give me your comments:

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

- Jason O

[Jdo300]

I would like to add following observations to my previous posting about the calculation of the phase angle between voltage and current.

The system can be designed in two ways:

1) High capacitance relative inductance (low resonance frequency)
Operating above resonance, phase angle decreases if speed decreases.

2) Low capacitance relative inductance (high resonance frequency)
Operating below resonance, phase angle increases if speed decreases.
This design can newer be a "run away" because when the speed increases to much, the phase angle will decrease and lower output (provided the resonance freq is not to high). 

So, how do I wind a coil with as little capacitance as possible and as large inductance as possible? Anyone with good advice?

Hi Rogla,

Very interesting thoughts there. What you described above reminds me of an interesting effect I noticed when shorting the output in parallel mode. For my setup, the resonant frequency of the system occured somewhere around 2600-2800 RPMs and if the rotor is shorted when the rotor speed is below the resonant range, the motor is very sluggish to start accelerating, but as the speed slowly approaches the resonant frequency, the acceleration of the rotor increases greatly and then stays constant above the resonant frequency until the rotor reaches the new steady-state velocity. The interesting thing is that the rotor will accelerate much easier if it is at or above the resonant frequency but not below.

As for your question about winding large L, low C coils, the best geometry for highest inductance would be the Brooks Coil. The proportions of width to height maximize the L and minimize the C of the coil. Also adding a metal core to the coil will increase the L but lower the frequency range at which the coil can be operated before the losses get too high.

- Jason O

[itsu]

Jdo300,  intresting video again, nice stuff you have overthere.

Concerning the coils used, you say and it shows on your diagram, they are 15.5uH each.

I find that hard to believe looking at those coils, and also with a 6uF capacitor in parallel, it
will resonate around 11Khz (http://www3.telus.net/chemelec/Calculators/LC-Calculator.htm)

So i guess your coils are 15.5mH, which will put the resonant frequency at around 375Hz (2812 RPM with your 8 magnets).

You also could try to reduce the high voltage and at the same time match the high impedance to a lower level by using a transformer
(less voltage, more current and impedance matching) like being mentioned by Bolt.
That is what i will try to do next.

I hope your motor survived that nasty noise at the end.

Regards Itsu