Bedini Ferris Wheel Regauging Motor

[Les_K]

Thanks Les,

We suspected that would happen. We are getting our extra rod in this next week and are anxious to get those slaves done. I think we are going to focus on getting the current circuitry worked out before we add more variables (slaves) to the mix. Once we get the slaves done, I will probably be picking yours and Mark's brain on the slaves positioning. It is still unclear to me how JB has his set up. On one thread we said move the center coil to the right 1/2 pole piece and move the right slave to the right 1/8 pole piece. I am assuming that means when the left slave is TDC. In the convention DVD, when he is showing the lady the coils, he says to notice that the left slave coil is closer to the main coil than the right one. So I am a bit confused on this and hoping you guys can shed some light on this.

Thanks,
Scott

Scott,
In post #68 on page 3 is a picture Jerdee drew of the alighnment.
1/8th on the right 1/2 on center and 1/4 left. all referenced to the same side of the magnets. the picture says it better..... Thanks Jerdee!
For when you are ready. That is what I used.

Les

[BrentA929]

Hall circuit

@All,

I hope I didn't confuse everyone with my ignorance...

Our hall is working properly and firing when the hall is over the timing magnets just like its suppose to!

I'll tell you what I did and where I was confused. When I put a voltage meter on the output of the hall when it was not over a magnet it was reading the battery voltage and I was thinking that this meant it was "on" and when it was over the magnet it wasn't reading anything and it meant that the hall was "off". However, just the opposite is true. The hall we are using is active low meaning it is "on" when it is pulled low. Thank you RS for your guidance with this and helping us to understand what we were seeing!


Many thanks, Brent

Hi Brent,

No , the PNP (MJE2955) is correct. If you are using an NPN there that is possibly why your coils are on when they should be off and vice versa.

Yes, the top of the coil goes to the 93's and the bottom goes to the 94's. This will give you a North pole on the top of the coil when it is on, which pushes away the North facing magnet on the rotor.

The ATS137 is also what I have ordered. They should be here any day now. Some wire arrived yesterday, so I expect the rest of the parts won't be far away. As soon as they turn up I can come and play in the sandpit with you guys.

I've attached an updated schematic, in the previous the zener on the cap dump was backwards.


John K.

[Les_K]

Oh, Just a side note about the outside coils.
I used a LCR meter and matched them to L not R.... Inductance, Not resistance. So I measured the center coil with all strands parellel and then measured the side coils and removed wire until they were 1/2 the inductance. But My meter will measure Z Impedance and I am now wondering If I did that wrong.... and should have done this with Z?

Les

[Rl2003]

I used the "L" as well Les. I believe we are good to go...
Mark

Oh, Just a side note about the outside coils.
I used a LCR meter and matched them to L not R.... Inductance, Not resistance. So I measured the center coil with all strands parellel and then measured the side coils and removed wire until they were 1/2 the inductance. But My meter will measure Z Impedance and I am now wondering If I did that wrong.... and should have done this with Z?

Les

[Les_K]

scaler south on trigger mags

Mark, It seems to work nicely.

RS,
I modified my trigger wheel. I did some preliminary testing and it looks like Scaler south switching is going to be the way to go.
I hadn't even thought of that in this application.

Thanks for the insight


Les

[RS_]

Les,

That's way cool...... I guess you rotated the magnets N out, and then shifted them over enough degrees to have a super south triggering the coils in the right spot.

Doing this, should make it have super narrow on pulses, depending on the distance between trigger magnets......

RS

[minoly]

you should be able to use scalar south 360 degrees around the entire magnet right? this IS a good idea. using the scalar south, the hall becomes more finicky, that is if you angle it one way or the other, you loose the flux.
here's a quick vid we did using halls to show the scalar south on the 3PM kit.
YouTube - Imaginary South Using Hall
notice only one side lights the LED.

Patrick

[Les_K]

Les,

That's way cool...... I guess you rotated the magnets N out, and then shifted them over enough degrees to have a super south triggering the coils in the right spot.

Doing this, should make it have super narrow on pulses, depending on the distance between trigger magnets......

RS

Well, this is interesting.
It looks like no matter where I put the hall the pulse width is about the same.
this makes me think the pulse width is set by the magnet gap.
the sensitivity is in getting the hall to trigger evenly. Any variation in the magnets or machining seems to be manefested in missed pulses more than pulse width..

Patrick: Finicky is the word!

It was pulling about 750ma before and now is bouncing heavily between 2 - 3
and all my transistors get very hot.

I'll try more tomarrow. But I made a big mistake machining this all out today. I would highly suggest using something you can stick the mags to and try it all out before you even think about machining a part. Ouch!

Les

[RS_]

Minoly

on this magnet arrangement, you are only going to see the Super South pole in a very narrow spot in between the 2 N out magnets at the closest point between them, and not in a 360deg pattern around each magnet, the farther up or down you go from the closest point of the magnets, the weaker and wider the Super South pole will get, till it fades out.....

[John_K]

Superpole South

Has anyone tried gluing 2 South pole magnets together to form a Super South pole? You could use disc ceramics and then adjust the position of the hall for the dwell.

Just a thought...


John K.

[minoly]

Minoly

on this magnet arrangement, you are only going to see the Super South pole in a very narrow spot in between the 2 N out magnets at the closest point between them, and not in a 360deg pattern around each magnet, the farther up or down you go from the closest point of the magnets, the weaker and wider the Super South pole will get, till it fades out.....

Your're right, some times I throw terms around like I think I know what I'm talking about

what I really meant there is: the hall will react to the south pole that is all around the magnets north - 360 degrees

So, if I have a .5 inch diameter round magnet north up (facing me), draw a circle around it that is 1.5 inch diameter w/ the magnet at dead center. the hall will switch at almost any point w/in the outer circle depending on the strength of the magnet, and the finickyness (is that a word :-) of the hall.

Super south, now you're talk'n. what about a semi-super-south? leave a wedged gap so you can adjust for on time, and you can use one of Jason's "equalizing magnets" on the other side of the hall to adjust for current intensity.

Patrick

[Rl2003]

Les and all,

This is why I have tried a optical switch. It seems much more stable and I have got
it down to as low as 250ma. But it seems to like it more at about 350 ma with the
cap I am trying out. My gap is .0625 right now and I am looking for a way to cut
a .03125 gap to see the difference in the amp draw. And I shorted something out
last night playing with it. So I have to find that first...

Mark

Well, this is interesting.
It looks like no matter where I put the hall the pulse width is about the same.
this makes me think the pulse width is set by the magnet gap.
the sensitivity is in getting the hall to trigger evenly. Any variation in the magnets or machining seems to be manefested in missed pulses more than pulse width..

Les

[Les_K]

Scaler Switching

the big difference I see in this scope shot is that the coils are now shooting up much higher when fired. No Idea why that would be.

Also I tried an experiment:
I wasn't sure the neos I eas using on the back of the ceramics were strong enough so I added another small neo on top of the neo on top of the ceramic...
Anyway the input current draw went up quite a bit. It seems like JB said if you pull the north's to much then you will begin to draw to much current.


anyway that's where I am at until I get more parts. Hope it is helpful.

Les

[Les_K]

Sorry was out of bandwidth so I deleted an older picture of my machine.
Here is the scope shot...

Les

[txaggie00]

Coil location

Thanks Les!

I have been analyzing his drawing, other posts and the video and I hate to say it, but I am still confused. Jerdee also has a drawing on post 198. In JB's DVD of the behind the scenes before the conference, he explicitly says that the left coil is closer to the main coil than the right coil. All the posts suggest the opposite. I have attached a picture of a still shot from a video clip that was posted on YouTube from the DVD. The perspective is not straight on, but to me, it appears that when the left coil is TDC, the main coil is is left of TDC and the right coil is right of TDC (although 2-dimensionally it looks like the right coil is left of TDC), which would coincide with what JB tells the lady about the left coil being closer to the main coil than the right coil. I realize it's not that big of a deal and our "sweet spot" probably won't be the same anyway, but it would be really nice to be able to match JB's setup (and performance)!

Thanks,
Scott

EDIT: Forum resized the picture. Here is the link to the full size image: Coil Lineup

Scott,
In post #68 on page 3 is a picture Jerdee drew of the alighnment.
1/8th on the right 1/2 on center and 1/4 left. all referenced to the same side of the magnets. the picture says it better..... Thanks Jerdee!
For when you are ready. That is what I used.

Les