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Author Topic: Muller Dynamo  (Read 4321962 times)

chalamadad

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Re: Muller Dynamo
« Reply #5460 on: January 13, 2012, 08:32:18 AM »
Marius, you will find that there is a sweet spot when to short your coil for highest output. When I was shorting with the reed switch I got best results positioning it somewhere between two coilsets and not necessarily exactly next to the coil. This was dragging the rotor but when I was shortin the output behind the FW bridge DC side the rotor would speed up and sort of make up for the drag.

What happens is that the reed shorting produces those large spikes on the scope. These create drag. But when the output side is shorted or connected to a load (which is not too big) or a cap the spikes will disappear because what you do is you take the energy out of the system and get a clean AC wave again that won't slow down you rotor but you get the extra energy out. But you cannot take more out than the spikes allow you to or your rotor will slow down quickly.

With the reed you can sort of shape the coils waveform on the scope. What you want to do I guess is to NULL OUT the part when the rotor magnet wants to escape the coil. So what you get is something like this:  --´\,--´\,--´\,-- And the spikes will be where the peaks of the wave are.

konehead

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Re: Muller Dynamo
« Reply #5461 on: January 14, 2012, 08:53:32 AM »
hi Marius and Chal and all
Had something successful tonight - made a adjustable-pulse width circuit using two pairs of bidirectional mosfets hooked up in series and each pair of bidiretional mosfets has its own halleffect.
One bidirectional mosfet pair has a 4421 driver, so it is normally-OFF and switches-ON
the other bidirectional mosfet pair has a 4422 driver, so it is normally-ON switches-OFF
The distance between the two hall effects, with each tripped by the same trigger-magnet, will determine the PULSE WIDTH of the coil-shorting event...
It is very important for a short pulse width to prevent lugging of rotor.
At around 60hz, I got the pulse width between 1/2ms and 1ms and the 22uf cap filled up like crazy -up to 300V and the rotor did not lug down in speed...in fact after the cap filled up some, it started to speed up a bit.
Last night I had 3.5ms p[ulse width at the same 60hz...and it LUGGED....
So figure 60hz has 8.3ms in one phase, from zero point to zero point, so in one phase of a sinewave, whatever the speed it is happening, you would want the coil-shorting pulse width to be about 1/8th to 16th of the length of one phase - so that is how much of the "peak period" the bidirectional mosfets should turn on.
Here is the circuit I tested out tonight that has adjsutable pulse width:
 

konehead

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Re: Muller Dynamo
« Reply #5462 on: January 14, 2012, 09:05:10 AM »
Hi all
One more thing, is that the coil short must be on the PEAK of the sinewave, not at the "zero line area" like Chal's drawing shows.....doing it at zeroline area makes very meager voltage rise in the cap - it doesnt lug being shorted in that area of sinewave since no real power is being pushed into the cap....
imagine a motor coil pulsing a magnet repulsive - there is a spot in timing at TDC where very slightly to the left of TDC will push the rotormagnet to the right, and very slightly to the right of TDC will push the rotormagent to the left...and there is a spot in timing at exactly TDC, that will not propel the rotormagnets to the left or to the right....that is the point you want to find when coil shorting and thats why you need the short pulse width, to capture only that exact TDC point where the rotor magnet does not care which way it moves from its reaction to the coil being shorted....

mariuscivic

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Re: Muller Dynamo
« Reply #5463 on: January 14, 2012, 10:09:52 AM »
Hi Konehead!
I did filled the cap without any drag from the rotor but is important not to lug the rotor when starting shorting. My new rotor will be ready next week and i'll begin experimenting with only 8 magnets all N or S. I will try your new circuit. I get the same results ( for now) with IRF840 wich is much more cheaper.
About the speed up effect: in my case it was the FWBR that wasn't working soo good when high spikes occured. Now i have a FWBR from a copmuter power source and the cap is filling faster without the speed up

chalamadad

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Re: Muller Dynamo
« Reply #5464 on: January 14, 2012, 10:31:43 AM »
Hey Kone, good work, interesting concept using the non-inverting and inverting driver. It could be useful as two-stage circuit as well using just one hall.

With a scope you can optimize the best points to short and unshort at both peaks of the wave. You just want the wave to either go up OR down (depending on the polarity) like a vertically stretched 'S'. You cut off one half of the wave but the amplitude (voltage) will stay high PLUS the spikes amplifications which fill your high voltage caps. (see below) Now one thing to try is adding more small caps in parallel to your first cap and see how they all fill at the same speed. This is not possible with just one big cap! After that discharge the caps to a load at the time when they are currently not being filled. It might be helpful to use a 1:1 transformer between the caps and the load.

Rotate this 90°:

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~
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konehead

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Re: Muller Dynamo
« Reply #5465 on: January 14, 2012, 08:07:05 PM »
hi Chal
Thats what I did last night, used scope to really see where the best points to short are at, (its the very peak of the sinewave) and also with the new pulsewidth adjsut circuit, also played around with pulse width too, using the scope. all the while watched the ammeter, and checked rpms with rpm meter.
What happens is if the pulse width is too wide, (or doubled -up) then you have "no choice" but to short down there at zero-line area, and leave the peaks "blank" as you describe... and yes, this will make it no-lugging but I didnt get the immediate huge voltage increase, and eventually voltage around 300V - from a "base" voltage of 10V.
Shorting coils down there in non-peak areas is around 6 times less voltage increase into cap - so there is some, and its slow to fill cap too...
I dont agree with your idea to short the peak as it descends or ascends, and to cutoff one-half of the wave....you posted a few days ago about this and that is why I did all this - to confirm its the PEAKS where you want to short and I havent been leading everyone astray down road to ruin and lugging of rotor too......
I will suspect that your reed switches have a duoble-pulse from the front and back edge of magnet tripping them - this especially happens if using  farily large rotor magnets to trip reed switches, and becasue you cant really nail the peak-period right in the midde, with a single quick very narrow pulse -  that is why your theory of shorting at the rise and fall and not the peak works best for you - thats all I can think of...
HOWEVER,  all this said, why not pulse sinewave  at the "ascension", and the "descension" and fill seperate caps (maybe) with those and at same time hit that peak period with the very short pulse width too....Ismael Aviso always talks about shorting five times per peak period - so combining your method, with mine, it would then be: twice at ascension, once at top of peak and antoher two times at descenision - this might really be something...just as long as it doesnt lug it could be great.
I agree with you that you wont be able to put this into one big UF cap - that big cap will have too much resistance and block most of the ringing (unless it is already 3/4 full or something like that) so better to do it into smaller caps....also once a cap reaches a level of volts, it does no good to put "lesser" jolts of voltage into it - its not going to fill any higher if the cap is already at 100V and you inject a pulse of 95V into it as example...
 

Magluvin

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Re: Muller Dynamo
« Reply #5466 on: January 14, 2012, 08:27:58 PM »
On reed switches

If you only apply the magnet to 1 end of the reed, it wont double latch.

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

 And you can bias the reed with a small magnet or even adjust the sesitivity using magnetic objects

http://www.youtube.com/watch?v=qYgs7dvyZqc
http://www.youtube.com/watch?v=rR7P-JSF6i4

Mags

chalamadad

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Re: Muller Dynamo
« Reply #5467 on: January 15, 2012, 10:32:28 AM »
hi Chal
Thats what I did last night, used scope to really see where the best points to short are at, (its the very peak of the sinewave) and also with the new pulsewidth adjsut circuit, also played around with pulse width too, using the scope. all the while watched the ammeter, and checked rpms with rpm meter.
What happens is if the pulse width is too wide, (or doubled -up) then you have "no choice" but to short down there at zero-line area, and leave the peaks "blank" as you describe... and yes, this will make it no-lugging but I didnt get the immediate huge voltage increase, and eventually voltage around 300V - from a "base" voltage of 10V.
Shorting coils down there in non-peak areas is around 6 times less voltage increase into cap - so there is some, and its slow to fill cap too...
I dont agree with your idea to short the peak as it descends or ascends, and to cutoff one-half of the wave....you posted a few days ago about this and that is why I did all this - to confirm its the PEAKS where you want to short and I havent been leading everyone astray down road to ruin and lugging of rotor too......
I will suspect that your reed switches have a duoble-pulse from the front and back edge of magnet tripping them - this especially happens if using  farily large rotor magnets to trip reed switches, and becasue you cant really nail the peak-period right in the midde, with a single quick very narrow pulse -  that is why your theory of shorting at the rise and fall and not the peak works best for you - thats all I can think of...
HOWEVER,  all this said, why not pulse sinewave  at the "ascension", and the "descension" and fill seperate caps (maybe) with those and at same time hit that peak period with the very short pulse width too....Ismael Aviso always talks about shorting five times per peak period - so combining your method, with mine, it would then be: twice at ascension, once at top of peak and antoher two times at descenision - this might really be something...just as long as it doesnt lug it could be great.
I agree with you that you wont be able to put this into one big UF cap - that big cap will have too much resistance and block most of the ringing (unless it is already 3/4 full or something like that) so better to do it into smaller caps....also once a cap reaches a level of volts, it does no good to put "lesser" jolts of voltage into it - its not going to fill any higher if the cap is already at 100V and you inject a pulse of 95V into it as example...

Hey Kone,

I think you misunderstood me or maybe I did not make myself clear enough. I agree the shorting must happen at the peaks of the wave and NOT when the wave is ascending or descending. Only this will give highest voltage spikes. My idea is to leave the waveform intact only when it either ascends or when it descends. I made a drawing to make it clearer what I said about cutting off one half of the wave. See below.

About the reeds: I think it is not shorting twice. It is shorting at one peak and unshorting at the other peak. Both shorting and unshorting at the peaks of the wave will create high voltage spikes.



mariuscivic

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Re: Muller Dynamo
« Reply #5468 on: January 15, 2012, 09:35:42 PM »
Hi guys!
Just a small video with shorting at both peaks
http://www.youtube.com/watch?v=pkRXmAsEUF0

konehead

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Re: Muller Dynamo
« Reply #5469 on: January 16, 2012, 04:26:32 AM »
Hi Mariu
 
Really nice simple video to see again -
 
If you put another coil spaced on stator plate exactly "in between" the rotor magnets, with your existing coil right underneath one of the rotor magnets as the spacing of the two coils, you will get a perfect AC sinewave if you want to try it.
 
If the coils is wound LeftHandRule, for example, then have the 2nd coil also LHR, but connect the OUT of coil A to the OUT of coil B - and connect in series too...so "ADJACENT PAIRS OF COIL CONNECTED IN BACKWARDS SERIES" is what I call it... the AC signal comes from the two leads of the IN of coil A and the IN of coil B...sort of treats the two coils liek one big long one sort of...
 
So if 8 magnet rotor, you could eventually pack the stator plates with 16 coils in the same spacing as described above too...but they better be aricores, since everythign is "inphase" and ferrous cores will cause bad rotational-lugging.... unless you did the odd number of coils vs even number of magnets Muller-thing....
 
Doing these two coils in backwards sereis, should double yoru power, since now you have twice as many peaks to short at...its what I am doing now in thing working on - I have 32 peaks to short per revolution since 16 coil -postions on stator plate in mine...
 
I got my pulse widht down to only .75 millisecond and cap fills just as fast as if it was 2 or 3 milliseconds - but you get rotor-lugging at 2 or 3 milliseconds, but none at all at .75 millisecond short
 

konehead

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Re: Muller Dynamo
« Reply #5470 on: January 16, 2012, 04:34:55 AM »
Hi Chal
 
Yes I am still a bit confused still - you are saying to short at one peaks but "unshort" at other?
How can it unshort if its already been shorted at other peak??
 
do yoy mean to leave ON (closed)  the short for the whole sinewave??? 
 
then un-short at next sinewave peak??
 
sorry I ams ure it is simple I just dont get it...I guess not sure exactly what it means to "unshort"
 
Maybe you mean have the timing of the openinig of the swtihc be at one peak?
and the closing of the switch at the other peak,
but still wiht very short pulse width;
so one peak is slightly advanced (unshorted-switch opened) to TDC and other is slightly retarded to TDC (shorted- swithclosed)???
 
 

chalamadad

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Re: Muller Dynamo
« Reply #5471 on: January 16, 2012, 09:03:06 AM »
Hi Kone,

I am not sure if it double latches or shorts and unshorts at the peaks of the wave. I was thinking it was shorting at the lower peak and unshorting at the upper peak because of the flattened out part inbetween. I had the high voltage spikes exactly at the upper and lower peak of the wave. It is more important to interpret or resemble the waveform I posted in the drawing above: one half from peak to peak is flat and the other one is near sine wave. I had exactly this waveform when I had best output using a reed switch. This was also when I had the speedup by shortin the DC output. If we can interpret the flat part as that there is then no magnetic field then there will be no drag at that point. If this is happening when the rotor magnet wants to escape I think this is what we want.

mariuscivic

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Re: Muller Dynamo
« Reply #5472 on: January 16, 2012, 10:02:15 AM »
Hi Konehead
0.75 miliseconds=750microseconds right?
i still get drag for 200-150 microseconds. Also noticed that the spikes are not so high when shorting for 200 microseconds

konehead

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Re: Muller Dynamo
« Reply #5473 on: January 16, 2012, 09:10:21 PM »
Hi Chal
 
OK that is what I got when I tested your idea too, with a long pulse widht, you dont have the swtich closed at the peaks, shorting the coil, instead you have it start to OPEN there....(and close on the toehr too is your idea) and I see what you mean now - but I dont think this is good way to do it.
You should in konehead-logic and method,, have ultra-short puulse widht that just shorts at both the neg and pos peaks - all the rest of the time the switch is open..
Now, if you had a coil and motor for it that ACCELERATESS under a shorted load, then that is whole different ball game for sure! - in that case it is probably better to do as you did, leave the coil shorted for very long period, and find good spot to open swithc, if at all, such as filling a huge UF cap which works like a shorted-condition

konehead

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Re: Muller Dynamo
« Reply #5474 on: January 16, 2012, 09:16:22 PM »
Hi Mariu
1 second = 1000 milliseconds...microseconds is one-millionth of second (10 to the 6th):
http://en.wikipedia.org/wiki/Microsecond