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Lam wound coils and mag size
By ghurd, Section Mechanical Posted on Wed May 4th, 2005 at 03:07:29 PM MST
How big should the magnets be related to the laminations

Hi all,
Working on a couple box fan type motor conversions.
Have gotten myself confused. Again.
The coils are wound on laminations, like a post with the top facing the magnets.
More like wrapped on a post, than inside a slot.
If the post or laminations and hole in the coil are 1 X 1",
How big should the magnets be?
Somehow 1 X 1" seems correct to me.
Same as the hole in the coils.
A friend had some good arguements at the time for the bigger the better, to totally saturate the lams.
Kind of seems it would have major cancellation.
These look something like an ECM (link), but with only 6 coils far from each other.
http://www.fieldlines.com/story/2005/3/28/44634/0927
I am not sure how the flux is acting on the coils in this situation.
Thanks,
G-

Lam wound coils and mag size | 34 comments (34 topical, 0 editorial)

Re: Lam wound coils and mag size (3.00 / 0) (#1)
by Gary D on Wed May 4th, 2005 at 09:41:04 AM MST
(User Info)

Ghurd, is what you're talking about similar to the link below? There are 2 updates you can click on that Dan did a long while ago... This may help others understand by seeing something similar? Gary D
http://wondermagnet.com/other/gentest.html

Re: Lam wound coils and mag size (3.00 / 0) (#3)
by ghurd on Wed May 4th, 2005 at 11:27:52 AM MST
(User Info)

Something like that, but the return flux path will be more complete.
And more of a radial flux design.
G-

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#2)
by kitno455 on Wed May 4th, 2005 at 10:28:09 AM MST
(User Info)

general consensus seems to be 1x1, but then you have some increased chance for cogging. larger mag will be over both legs of the coil, and at least partially cancel out, giving less output, but should cog a little less. smaller mag gives less output, but might cog less too.

making it multi-phase may help the cogging some, if that turns out to be a problem.

allan

Re: Lam wound coils and mag size (3.00 / 0) (#4)
by ghurd on Wed May 4th, 2005 at 11:37:51 AM MST
(User Info)

Cogging will be reduced with multi phase.
But kind of inside out from most 3PH designs.
Like 3 halves of a 2 phase?
Or a 8 magnet 6 coil with only half the magnets?
G-

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#5)
by ghurd on Wed May 4th, 2005 at 11:48:31 AM MST
(User Info)

Maybe I should add something.

Depending on magnet size...
Is the flux going straight down the lams?
And somehow missing the coils?

When the magnet is over a coil leg,
the air gap is 1/32 to the lams
or 2" to the lams straight out from the magnet?

Am I just overcomplicating the situation?

I only have 1 shot at each different magnet rotor. Experimenting with different magnet sizes can't really be done because I can't put metal back, and no 2 are the same!

Thanks,
G-

Re: Lam wound coils and mag size (3.00 / 0) (#6)
by kitno455 on Wed May 4th, 2005 at 02:01:28 PM MST
(User Info)

well, the flux can bend, especially in the presence of permeable materials like iron. so if your mag is wide enough to be over the coilleg and the stator tooth at the same time, it will still send most of its flux down the stator tooth. now, once that mag is past the stator tooth, it should hopefully be near the next tooth, so all the flux lines will jump from one tooth to the next. (of course, its not really instant like that, but you get the idea)

this thing has a 6 pole stator, best bets are going to be 6 mags single phase, or 4 mags 3 phase?

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#7)
by ghurd on Wed May 4th, 2005 at 02:34:08 PM MST
(User Info)

Its 4 mags 3 phases.
Space for the mags, available space, and the shape of the top of the lam 'post'.
It's top is a "T" .

They all look about like this... (thanks Norm!)
http://www.otherpower.com/images/scimages/22/Laminate.gif

The 2nd one.

See how I am confused about how the flux gets to
or through the coils?

The "T" looks like it may short the flux without cutting the coils. Jumping, bending, shorting, whatever it could be called.

Or the "T" looks like it will short the flux without cutting the coils unless there is a magnet over 2 adjoining lam posts.

I would just try it.
But I will not know what is wrong if I don't get how the thing is supposed to function.
(Like the guys who put all the magnets in same pole up!)
Something is always wrong, but I know before it is done what and how it is wrong!

G-

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#8)
by kitno455 on Wed May 4th, 2005 at 02:52:03 PM MST
(User Info)

wow, ok, yes you are right. if you have a N and a S under one tooth at the same time, i would think that nearly none of the flux will go thru the coil.

cut the sides off of the T somewhat.

any chance you could get two of these with the same stator lams and alternate them into a 12 pole setup? that little less iron would reduce cogging some, and give you a higher effective speed and longer coil legs.

allan

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#11)
by ghurd on Wed May 4th, 2005 at 03:38:43 PM MST
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With the N under (over?) one lam, the next mag will be exactally half way between the 2nd and 3rd lam. Hence reduced cogging.

But only one tooth would be under one mag at any time. The teeth are 150% seperate from the mags.

But 6 coils and 12 poles? Wouldn't the mags short between the top of the "T" to the other side of the top of the same "T"?

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#12)
by kitno455 on Wed May 4th, 2005 at 04:07:00 PM MST
(User Info)

ok, if you never have a N and a S under the same stator tooth at the same time, then the flux pretty much has to go up and link with the coil and come back down the next tooth.

my idea about the 12 pole involves cutting the T's to be more like I's (shorter cross-bar).

than you could get more mags, and still keep it three phase.

you got the mags yet?

how big is the head on the T, 1x1?

allan

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#16)
by ghurd on Thu May 5th, 2005 at 08:14:43 AM MST
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The one I'm starting with has 3 parallel wires about mid 20's gauge.
Thats hevy enough for this. And if it only makes 9v, I can series 2 coils from the same 'T', or if it only makes 5v, I can series all 3.
If it makes 12v I can parallel all 3.

The top of the 'T's are 1.5" wide, 0.5" thick.
The steel in the armature is 0.5" thick.
The ID of the 'T's is just under 3", armature too.
Gap between the 'T's is just under 1/8".
The shaft of the 'T' is 1/2" thick, 5/8" wide (best guess).

The magnets I am willing to try in this are 1x1x5/16", 3/4x3/4x5/16", 1x1/2x1/8", or 1x1 cylinders (don't think the cylinders will fit very easy because of 3 big holes in the armature). All neos.

Probably will go with the 3/4 square x 5/16".
Unless there is a reason to go with another.

I hate hacksaws.
G-

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#18)
by kitno455 on Thu May 5th, 2005 at 09:04:48 AM MST
(User Info)

the single most useful tool i have ever bought is a 4.5 inch angle grinder at the sears scratch and dent store. i have not touched a hacksaw in years.

lets see, we want to keep the gap between the mags the same as a stator tooth width, so that you never have a N and S under the same tooth at the same time. that means a 1.5 inch gap, right? so 4 poles means 4 gaps totalling ~6 inches, plus ~3 inches of mags on a rotor of ~9 inches circumference. so the .75 mags it is. thats not much mag. you will need all three coils in series on each tooth i bet. stacking them, and/or making curved iron pole pieces would help.

the only other option i see is stacking up two sets of lams alternating, make 12 poles, cutting the top of the T down to .75 x1, putting plastic strips in the gaps in the teeth. then you could use your 1x.5 mags vertically... but alot more work.

allan

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#20)
by ghurd on Thu May 5th, 2005 at 11:54:57 AM MST
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I hope the only cutting will be the armature for the magnets.
My grinder filled with Al last time I tried that.

If I cut the 'T' to 'I', I think the cogging would be past anything I can actually use.
Could be way off base on that. This is a lot different than anything I ruined... um, I mean 'made' yet.

G-

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#9)
by Flux on Wed May 4th, 2005 at 02:54:47 PM MST
(User Info)

Much confusion is caused by thinking about flux cutting coil sides, its far easier to think about flux linkage through the centre of the coil.

Virtually all your flux will pass down the teeth and in doing so will link the coil. If you think about flux cutting the coil sides you will have the same problem as with iron cores and slots, the flux snaps from one tooth to the next and links the coil and does not cut the sides as would be assumed from the basic idea of a wire in a magnetic field.

The linkage concept is also better to use with air gap alternators as it is the flux linkages x the number of magnets per second. This is angular velocity and the confusion about linear velocity and it being greater at large diameters is a red herring.

The biggest disappointment you are going to have is with cogging. With single phase it will be impossible, with 3 phase you may keep it within reason.

Hope this makes sense, whatever size of magnet you use as long as there is some gap between them the flux will all pass down the teeth. If you skew to reduce cog then it will be better to keep the magnets about the size of the teeth.

Flux

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#10)
by Flux on Wed May 4th, 2005 at 03:14:45 PM MST
(User Info)

I have just looked at the pictures of the core, I assumed they were like the first one. If like the second one it will only work properly with 6 magnets single phase.
With 4 magnets you will have most of the flux shunted across the pole tips.

If desperate you could cut back the tips to less than the width of the magnet but to be quite honest I would not bother with that type of core, I think it will be a cogging machine and not much else.

If you can find a decent core with the normal slots it will be much better.
Flux

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#13)
by ghurd on Wed May 4th, 2005 at 05:23:04 PM MST
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Hey Flux!

Really glad you came by!

This is totally different approach. I think.

This is 3 totally seperate phases.

Therefore 2 of 4 magnets are totally irrelevant at any given time. Other than reducing cogging and completing the flux paths by what I have extrapolated by my readings here.

And 4 of 6 coils are totally irrelevent at any time.
So 2 of the 4 magnets are not expected to be producing.
And 4 of the 6 coils are dead.

Opposite coils are connected for charging voltage.

The "T" tips are 150% seperate from the active magnets.
No magnetic shorting between the same tip should occur.
Cogging should be reduced to the least for the situation.
At least I think...

My question could be explained better if the magnet and tip count was only 2.
With some extra iron to reduce cogging?

What really happens, flux speaking, in the otherpower link above.

I spent about 2 hours saying this, hit the wrong button, and it is all gone!
The first time was much better.
G-

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#14)
by Flux on Thu May 5th, 2005 at 01:10:19 AM MST
(User Info)

Having done a quick sketch, you can forget my second post, the flux shorting I was worried about occurs on the inactive poles anyway, you are right that the active pole arc is not across more than 1 magnet.

If you can solve the cogging it should work. It is similar to a high tension magneto circuit and with them the better they cog the better they work. Interesting idea though.

Flux

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#15)
by kitno455 on Thu May 5th, 2005 at 07:56:59 AM MST
(User Info)

i am confused. if you have a N mag dead center under a stator tooth, its flux goes up and thru the coil, and bends to the right and left thru the outer, circular part of the lams. at the same moment, you have a S mag under the gap between two stator teeth, so the flux from that N mag comes down, and thru the first of those teeth, and into the mag, linking that coil.

so you cannot say that those S mags or those two coils are doing nothing, right? i mean, a moment ago, a N mag passed that spot, and made a positive bump as it engaged the coil, and a negative bump as it left. now a S mag enters, and it makes a negative bump, and a positive one on leaving. so the trick is to get the leaving bump of the N mag to align with the entering bump of the S mag?

or am i completely missing the point? a coil with a moving mag under it is always doing something, right?

allan

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#17)
by ghurd on Thu May 5th, 2005 at 08:41:17 AM MST
(User Info)

(feel free to jump in here again Flux!)

Right!
Now you are confused too!
See what I mean?

But the mags between teeth will be at their lowest potential, with half the flux to each tooth.

I still don't get if the mag makes 1 bump at the 'center' of the tooth,
or 2 bumps, one at the start and one at the finish of each tooth.

The tooth grabs all the flux, say 'North flux', and sends it down and around, the whole time. The field builds then colapses.
With that line of thinking, there is only 1 bump, and the WHOLE coil is active, NO dead wire at all!

The other line of thinking, 1 bump on the 1st side or leg of the coil as the mag comes, one bump on the other leg as it leaves.
But the 'T' grabs all the flux right? So there can't be 2 bumps. Can there?

If there is 2 bumps, that means the magnet exactly between and over 2 teeth is acting on them, and the magnet exactaly over 1 tooth is dead!

Even if the thing works well when its done, I still won't be able to tell whats going on, as my best meter with a HZ setting has drowned... long story.
G-

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#19)
by kitno455 on Thu May 5th, 2005 at 09:37:03 AM MST
(User Info)

ok, this much i know, as i have tested this with an oscilliscope. a single mag makes two bumps. end of story. one bump when the flux breaks the first leg, and the opposite bump when it breaks the second leg. when i made my coil larger (greater distance between legs) there was a flatspot of no output when the mag is in the center of the coil.

i do not know if you would say that this effect is caused by change in flux (first increasing, then decreasing) in the stator tooth, or by lines of flux cutting thru the free space between teeth (and hence the coils).

i just thought of a way to test it, though. what if i hold my test coil so that one leg has a much wider airgap that the other? if it is 'flux cutting coil leg', then one bump will be bigger than the other. if it is 'flux density change in coil' then the bumps should be more similar in size, right? (or perhaps tapering, i dunno, maybe not such a good test)

allan

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#21)
by Flux on Thu May 5th, 2005 at 12:53:23 PM MST
(User Info)

Voltage is proportional to rate of change of flux. When a magnet is directly over the leg the flux is a maximum and the voltage is zero. As the magnet approaches and departs from the leg the flux change is rapid and the voltage peaks. I said that this type of core is similar to a ht magneto and in that case the idea is to make the rate of change of flux and hence the induced volts as great as possible.

This core will produce very spikey voltages with high peaks and fairly low average level unlike conventional generators that produce more of a rectangular voltage waveform with a lower peak but higher average value.

As a 3 phase line voltage is the vector sum of 2 voltages of different phase the resultant line voltage in this case will be strange at least and the average power out may be rather disappointing.

The other snag is that the leakage reactance will be about as high as you could make it and above a certain turnover frequency it will limit to constant current no matter how fast you turn it.

I have tried ht magnetos as pm generators and they are not very good. A large tractor magneto will only produce tens of watts, you are unlikely to have much more room for magnets than a smallish magneto.

Flux

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#22)
by kitno455 on Thu May 5th, 2005 at 01:15:11 PM MST
(User Info)

"Voltage is proportional to rate of change of flux. When a magnet is directly over the leg the flux is a maximum and the voltage is zero. As the magnet approaches and departs from the leg the flux change is rapid and the voltage peaks."

i am really confused now. this statement would indicate that there should be 4 bumps per magnet pass, which i most definately do not see on my scope. i am seeing something that looks more like the voltage peak is when the mag is directly under the coil leg.

i gotta do more experiments....

allan

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#23)
by Flux on Thu May 5th, 2005 at 01:56:40 PM MST
(User Info)

Sorry Allan I think I caused confusion there. I was referring to the legs of the magnetic circuit, I think you are playing with a coil with no iron core and you are referring to coil legs, a term that is new to me.

If you are passing a magnet across a coil you will see a peak one way as the magnet crosses one coil side ( leg ) it will fall to zero as the magnet reaches the centre of the coil where the flux is fully linked and you will see a peak of the other polarity as the flux linkage falls when the magnet moves out from the centre and crosses the other side.

With no core the flux change will be gradual and the waveform will be rectangular for a single turn or more nearly a sine wave with a multi turn distributed coil. You will never see the very peaky wave unless you have an iron core where the flux moves from zero to maximum in a very short time.

Flux

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#24)
by kitno455 on Thu May 5th, 2005 at 02:10:09 PM MST
(User Info)

ok, thanks. i will try some experiments with laminated cores next to see the effect you are talking about.

sounds like with lams you would be better off with a huge number of phases, like 8 mags and 7 coils, and rectify each one separately, then add together. might help the peakyness/cogging. but you need an odd number of coils....

allan

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#25)
by ghurd on Thu May 5th, 2005 at 05:15:01 PM MST
(User Info)

Thanks Flux!

As this is like 3 single phases,
Won't the leakage reactance be limited mostly because its only 1 pair of coils at a time? Even if the are far appart. The other 2 phases shouldn't interfere much?

Is all that not related, because the high frequency kind of keeps the inductance high, almost like self cancelation?

Been a long long time since I heard "leakage reactance".
G-

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#26)
by ghurd on Thu May 5th, 2005 at 05:25:27 PM MST
(User Info)

I'm off to start sawing for 4 of the 3/4" square 5/16" mags.
If the wife doesn't get home early, should be OK.

I will post in this thread the results either way.
G-

Almost NO Cogging! (3.00 / 0) (#27)
by ghurd on Fri May 6th, 2005 at 09:37:37 AM MST
(User Info)

Have the 4 magnets stuck to the armature under their own power.
Not perfectly set, but quite close.
The air gap is closer than I expected, with a hacksaw and file.

Gave it a spin!

Almost NO Cogging!
What cogging there is seems weak and long.
Not like bang, bang, bang. More like whoosh, whoosh, whoosh.
Sorry if I get too technical. ;)

It will not free wheel along, partly because I do not want to turn it that fast without glue, and partly because I got the armature / rotor in upside down and the bushings are on shaft surface rust.

With the factory wiring configuration... Out of curiosity, put a meter on the high ohm (32) windings. Got about .7VAC at maybe 100 RPM. That much seems strange to me as all the coils should be canceling each other. The low ohm (16) windings do not register any voltage.

Next is seperating and reconfiguring the coils.
Should be easy enough. Just time consuming. Not today.

G-

Re: Almost NO Cogging! (3.00 / 0) (#28)
by kitno455 on Fri May 6th, 2005 at 09:53:48 AM MST
(User Info)

the no cogging makes sense, i mean, you never had a point where all 4 mags are against the side of a stator tooth at the same time, and the stator teeth are much wider than the mags.

allan

[ Parent ]

Re: Almost NO Cogging! (3.00 / 0) (#29)
by ghurd on Fri May 6th, 2005 at 10:13:33 AM MST
(User Info)

That is why I wanted to try 4 mags on 6 teeth.

The fans are everywhere, but no one has really had very good luck with them, often due to cogging.

With no cogging and good magnets, I still think these things have potential, with the factory coil ends reassigned. Like Johnlm said in the 'box fan...' thread, there are a lot of ways to re connect what is already there.

Also wanted to avoid cutting the 'T's to 'I's. I believe the lams get shorted.
And cogging gets worse.

There is that thing with the bushings instead of bearings.
I'll burn that bridge when I get to it!
G-

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#30)
by ghurd on Sat May 7th, 2005 at 10:55:52 PM MST
(User Info)

Hey! It works!

It got a little longer than I expected. A few interesting things at the end too.

Turns out there are 4 wires.
Cut one tooth's coils seperate from the other teeth, and extended all 8 ends.
One wire seemed a little smaller than the others, but did not measure it.

With 2 coils at 2 ohms and 2 at 3 ohms, I expected the 3 ohm coils to make more volts, because they look to be wrapped with all the same number of turns.
Each coil made 2.00 volts AC open.

The 3 ohm coils made 0.650 amps AC shorted.
The 2 ohm coils made 1.05 amps AC shorted.

Here is where things go bad, in a funny way.

It was looking promising. So I connected all 4 coils on that tooth in series.
Guess what. 2 volts AC. Short circuit AC amps, 0.120A.

Added a bridge and very small cap, thinking the Hz had the meter confused. The volts were about right, at around 2 (even with the bridge), and the amps were still about 0.12.

Started at the beginning with the bridge and cap, one coil at a time. Turns out he tinned the stripped wires he added and the flux residue was causing trouble with the ohm meter not getting any reading. That took a while to figure out! Re stripped the 8 wires.

Reconnected them in series and checked the VAC. The same. 2+2+2+2=8 when I was in school. Still only had 2VAC. (Scratch head like Oliver Hardy.)

Running out of time.

Then, I remembered placing the magnet rotor. 16 wires out the vent holes, 8 on the coils of one tooth we were testing, 8 where those formerly connected. A mess, but got it so 4 wires came out of 4 holes.
Spun the rotor. OK for half a tun, then maybe a magnet is rubbing? No. 4 wires slipped out between the teeth and tangled with the magnets. They should be OK.
But they must have shorted during testing.
Or chucking the drill on and off so many times caused the wires to stip insulation and short on the sheet metal motor housing.

Too late to keep going. Had to stop. Shorts and flux insulating make bummers.

But I am quite sure it is shorted near the extra wires for testing.
I think it should be 11.3VDC open with all 4 coils per leg in series, seriesed with the mating coil 180' accross is 22.6VDC open, minus 1.0 for a good bridge, and that is 21.6VDC.
For the amps, I guess it will be about 0.8 short, too tired now to get a calculator.
Don't know if I know how to figure it with much accuracy anyway.

One VERY good thing. This is all form 1 coil array, figuring some for when it is connected with its mate in phase 180' accross from it.
But there are 6 coil arrays, or 3 pairs of mating coil arrays, so that should be about 2.4 amps shorted. (?)

The cogging, even when shorted, was very light. Shorting the outputs had NO noticable effect on how hard it turned. No skewing or offset for the magnets.

The rotor, I believe, does not have enough iron to be perfect. I will add fender washers to the top and bottom to help the flux path. The magnets are N45 and 3/4" square 5/16" thick, but the laminations in the rotor and stator, are only 1/2" thick. The rotor including the aluminium is 3/4", so it glued together nice.

The stator laminations are fine. There is 'virtually' no flux leakage to the outside of the motor. Tested with a 18" hanging test clip and could not be sure it was attracted.

I think the 20" fan blade that came with the motor will turn it in a light wind. That was not expected.

Next will be to get the opposite pairs all connected together in series, rectified, then parelleled and see how it goes.

I don't recall the drill and generator RPMs. Probably about 450. Guessing.

Should get it wired middle of next week.
I'll post it here.

Is anyone still following this?
G-

Re: Lam wound coils and mag size (3.00 / 0) (#31)
by kitno455 on Sun May 8th, 2005 at 10:06:24 AM MST
(User Info)

still here. by the middle of next week, just do a new, recap from the top post. and try to get some pics. you may have developed a great starter kit for budding windies to try, those fans are everywhere.

allan

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#32)
by ghurd on Mon May 9th, 2005 at 05:05:48 AM MST
(User Info)

A couple strange things.

Ohm's law.
Very strange thing I noticed, that never happened to me before.

The 3 ohm coils, 2.0v open and 0.650 shorted, 2v=3ohmsx0.650.
The 2 ohm coils, 2.0v open and 1.05 shorted, 2v=2ohmsx1.05.
All those numbers are what was tested and they are only off by 10ma and 50ma.

This has never happened for me before.
I do not remember it happening to anyone else either, but never checked.

Maybe this 'design' is better than most of mine, where I am using just what I have here.
Usually my 'designs' are stuff that 'almost' fits together.
Meaning the mags are too wide, too narrow, too long, too short and other problems like that.

The other strange thing.
Usually as the meter 'ticks', the V or A reading fluctuates, up and down.
These readings were as stabile as could be. The readings just stayed there the whole time. The 0.650a probably fluctuated the most, but only a swing of +/- 5 or 7 ma.

The only other gennerators I tested so stable were brushed PM motors with high commutator counts, and turning faster than they did as a motor.

Has the Ohms Law test happened for anyone else?

G-

[ Parent ]

Re: Lam wound coils and mag size (3.00 / 0) (#33)
by ghurd on Fri May 13th, 2005 at 05:22:27 PM MST
(User Info)

Not forgotten.
Work has kept me from getting much done.
G-

Re: Lam wound coils and mag size (3.00 / 0) (#34)
by ghurd on Sat May 14th, 2005 at 07:55:07 PM MST
(User Info)

Looks like Wednesday 18th before it gets soldered up.

[ Parent ]

Lam wound coils and mag size | 34 comments (34 topical, 0 editorial)

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