Muller Dynamo

[David70]

@woopy
looks that your magnet/coil gap is too large. What is it in reality?
are you talking about one single coil output or 2 coils connected top and bottom?
this will help me  and others to continue or not.

[hartiberlin]

Hi Laurent,well done.
Please put a 5 Ohm Resistor as a load across your coil and please show a scopeshot of it at the same RPM.
This way we can see how much output power we can expect.
Many thanks in advance.
Regards,Stefan.

[Bruce_TPU]

Hi all replicators

i did not received the litze today but i did some experiments with my setup

1- i installed all the ferrite core (without the coil) in theyre place on the stator and the magnet in the rotor.

2- i tried to spin the rotor with the center motor but with only 1 stator to see the anticogging = very low cogging but tremendous vibration, due to the assymetry of attraction between one stator and the rotor.

3 - i installed the upper stator and super smooth rotation , no more vibration  . I speed up the rotor to 1280 RPM  really smooth.

4- i installed my small coil which is 450 turns of plain 0.3 mm wire , on one core.

  some datas :  the coil naked (without core ) is 5.6 Ohm DC resistance and 2.04 mH inductance
  once installed on the core in the stator  the inductance is 5.5 mH when the coil is between 2 rotor magnet and the inductance fall to about 2 mH when at TDC    with a rotor magnet. If i add a stator neo mag at the end of the ferrite core the inductance lowers a bit.

5- I speed up the rotor to 1280 rpm , the power is 2.7 volt at 180 mA  = 0.486 Watt (  for info,the motor is rated at 12 volt so at only 2.7 volt it works at a very low efficiency)

6- take some scope shot with different stator position and see the result in the pix.

No doubt at 1280 rpm the small coil can reach 10 voltpeak with the small neo in a repelling position.

Hope this helps

good luck at all

Laurent

Hi Woopy,

You want the stator magnets in REPULSION to the rotor magnets.  You want the b field of your coil in ATTRACTION to the rotor magnets.

I hope that helps!

Cheers,

Bruce

[nul-points]

[...]
6- take some scope shot with different stator position and see the result in the pix.

No doubt at 1280 rpm the small coil can reach 10 voltpeak with the small neo in a repelling position.
[...]
Laurent

way to go woopy!

thanks for the great feedback from the basis of an actual build - just what we need

so:
- stator mag in attraction ~12.5V pk-pk AC
- no stator mag ~15V  pk-pk AC
  - stator mag in opposition ~20V pk-pk AC

this supports what both Romero and Fausto reported as the best config

iirc Romero said he achieved approx 11.5V DC across single gen coil pair & then approx 15V DC when all o/ps joined (& with buffer cap?)

looks like you're getting pretty close, even before doing any tuning

félicitations!
np


http://docsfreelunch.blogspot.com

[neptune]

@Tudi .Romero himself said that it was likely that there would be many more replications than successes .I am reminded of a sick experiment that was shown on a TV Documentary . Basically a rat was put into a water tank that it could not escape from . The object was to see how long it took to exhaust itself and drown [isn`t science wonderful] . It was discovered that if a rat was rescued just before it drowned ,and given time to recover , it would struggle to survive far longer  before giving up the next time . The difference was , it believed in the possibility of success [rescue ] . My point here is that people will struggle for longer , knowing that success is a distinct possibility . I just hope they don`t have "rat tanks" at Want Dynamo Bay .
   Can someone educate me about Hall effect switches please . Presumably , they switch on as they approach a magnetic pole .Does it matter if that is a north or a south pole .And do they switch off as soon as that pole recedes from the switch? Assuming the motor works on attraction , how is the coil switched off at top dead centre so to speak .