Muller Dynamo

[konehead]

Hi Mr uu

It depends on lots of things besides the widths of coil and widths of magnets - such as aircoil, or coil with core in it - when you have core, then the core gets the "brunt" of the magnet, and the core is what gives the "signal shape" to the coil, and its not a direct magnet-coil thing going on, like in an aircoil.
yes I agree its the edges of the rotor magnets are what induce the peaks in an aircoil...But wha is interesting to me at least, is  it makes no sense when using hockey-puck shaped magnet that there are two "edges" to magnet, since you can twist the rotor-magnet around, and it doesnt make any difference to the signal-shape(this makes no sense to me at least!)
While, if you use a rectangular shaped brick or block shaped magnet, then theer is an obvious N-S polarity to the ends of the magnets, the sides, and the faces.....(why Beardon alsways calls magent "dipoles" since there are 6 sides to dice, and 6 sides to magnets)
Also the speed in rpms of the rotor makes a difference in the signal-shape too in how huch time the magnet gets to react to the coil...
I personally like to string two "adjacent" coils on a coil-plate  connected together  "backwards in polarity" and in series too, and then have one magnet in rotor pass by each, and so not have a single magnet for each coil, ( this is with aircoils) this gives a perfect AC sinewave as shown....this means explained in another way, if 8 magnet rotor, you would have 16 coils on coil plates each side,  (this mullergen style sort of ) wiht 8 of those coils face-on with the magnets to get the perfect sinewave shown here with photo of AC signal from coils indeuced rotor of 8 all-N magnets and it has 16 aircoil positioned each side:

[mariuscivic]

Hi Konehead
Thank you for sharing your Romero muller variant photos.
You have a strong magnetic field there from all those backing magnets. If the rotor is driven by a hall sensor; are you sure that is not affected by the backing magnets? If is not affected then you might not want to touch it and leave it like this for further experiments.
Still shorting the full wave and having fun with this. I tryed a lot of different coils and every one behavies differently.
There is one partycullar coil(directional) that i can short it at very high frequency with all most no lenz (only 2mA more at 1800rpm).The bad thing is that when i try to charge a cap (doesn't matter the value) it makes huge lenz, more than normaly).
I'm shorting the coil with mosfets that are driven by a flyback circuit were i can adjust pulse width and frequency(http://www.eleccircuit.com/efficient-flyback-driver-circuit-by-ic-555-irf510/).
This circuit is ok but is not giving me the signal that i want: it can not make the ''pulse'' shorter than ''no pulse''
Can any one help me with a better circuit? 
Thanks!

[gyulasun]

Hi Marius,

Here is a 555 timer circuit with independly variable duty cycle and frequency adjusting possibility:

http://www.overunity.com/8597/solid-state-orbo-system/msg234095/#msg234095 

The output of this can go directly to the MOSFET gate as shown in your above link or if you could use a MOSFET driver like TC4422 or 4421 etc it would give a faster switch.   Also if you could obtain the CMOS version of the NE555 like LMC555CN from National Semiconductor or TLC555CP from Texas Instruments, then these types have much less fall and rise time output pulses then the old NE555 bipolar process type have, so they are able to switch faster (you could omit the 2N2222 driver but just test this, it is better to have an "isolating" stage between the MOSFET and the output pin of the 555.  And the CMOS version is fully pin compatible with the old NE555.

Gyula

[mariuscivic]

Thanks Gyula!
I'll try it presto 

[crazycut06]

Hi Gyula,
    Nice simple circuit, what cap value connected to pins 2&6 would generate a 2mhz frequency, would it be a higher or lower value? sorry for the dumb question, i don't have an ocilloscope to check.


    Thanks!