Muller Dynamo

konehead · January 16, 2012, 03:34:29 PM

Hi Mariu
Looked at your video again - are you using "bidirecitonal mosfets" - two at once, connected at the gates and source, with switching happeing between the two drains? With 10K "turn off" resistor across the double-gate over to the double-source leads? Cant tell from the video what yoru swithcing is...
also, what I am testing with the series-pairs of coils is a 60hz AC sinewave and the big 16" wide rotor with 8 wide spaced magnets only goes 250rpm, so when you only do .75millisecond pulse widht to coil-short it, the percentage of the phase for the short is fairly low (one phase zero line to zero line at 60hz is 8.3milliseconds)..so figure I am around 11 or 10% "duty cycle" to a phase in how long to do the coil-short at peak.
But you are goig near 2000rpm, and with 8 magnets in small rotor that is much faster speed - not sure exactly right now but counting both pos and neg peaks you might have near 140hz (?) and your overall phase-lenght of a peak-period migh be only 3 or 4 milliseoncs not sure.... so the percentage of time to have coil short happen within the oveall phase-length would/could need to be shorter still, to be same proportion/ratio as the 10 to 11%..

mariuscivic · January 16, 2012, 06:20:46 PM

Hi konehead
-picture with the shorting circuit (hope the ingeniers will not scream at me)
-picture with scope while shorting at peak. One square has 200uS so this means that my short is a little longer that 200uS

Khwartz · January 18, 2012, 01:47:01 PM

Quote from: mariuscivic on January 16, 2012, 06:20:46 PM
Hi konehead
-picture with the shorting circuit (hope the ingeniers will not scream at me)

Hi Maruiscivic,
I don't see any driver in your schematic for the MOFSETs, is that's normal? don't you use a 4421 or a 4422?

mariuscivic · January 18, 2012, 03:03:16 PM

Quote from: Khwartz on January 18, 2012, 01:47:01 PM
Hi Maruiscivic,
I don't see any driver in your schematic for the MOFSETs, is that's normal? don't you use a 4421 or a 4422?

No driver Khwartz ; (i couldn't find any of 4421 or 4422) and it works fine just like that

Khwartz · January 19, 2012, 04:19:20 PM

Quote from: mariuscivic on January 18, 2012, 03:03:16 PM
No driver Khwartz ; (i couldn't find any of 4421 or 4422) and it works fine just like that

hehe, cool cause cheaper and easier

Very thanks for having specified.
I'm not yet ready to replicate the devise but very interested to see where you'll go with, trying to understand what is going on before could be to try myself

So thanks for sharing

(even it's hard sometimes for not english tongue $:-\$ )

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Here is a link about a vid, but it's about a part of the written comment that makes me much think to what Kone said about "TDC". Hope it could help