Muller Dynamo

[Magluvin]

I would try 4 and 3 bifi first. Maybe measure the capacitance and try to measure the inductance and calculate.

There most likely wont be any ringing at the Golden freq, because of the load. But at that freq the height of the voltage may be higher.  ;]

Mags

[4Tesla]

Hi Mags,

How do you find the resonant frequency and it's rpm for a coil?

Thanks,
4Tesla

[Magluvin]

Hi Mags,

How do you find the resonant frequency and it's rpm for a coil?

Thanks,
4Tesla

Hey Tes

I would say to add a resistor in series and connect a signal gen. Then measure the voltage across the coil. When its at its highest, your there.  =]

Mags

[Magluvin]

And use a scope to measure, as a meter may not be accurate at high freq.

Mags

[Magluvin]

Lets say the rotor is at 1200 rpm and 8 mags on the rotor.
That gives us 9600 magnet passings per min, per coil set.
Divide by 60 (sec) and we have 160hz.  These are hypothetical values and how to calculate. The tuning will be to get all coils very close to 1 freq of operation. then get the rotor to that speed, how ever.  If the speed cannot be had, then a lower freq coil will be needed.


So we are looking for 160hz range for coils of recommended build.  The fine wire of the litz will provide more capacitance than just 2 strands of a normal bifi due to more surface area of the fine wires for the capacitance plates.

In the pic of the bare coils on the pexi that we see more than 2 wires hanging from each, probably 1 of the 3 is 2 connected and not tucked away yet. ;]
i would say that if there are 2 coils with 2 hanging, that those are the drivers.


mags