PSN-L Message - Subject: Re: Faraday's Law

Mike, This is interesting........I what to see if I understand. 1. did you use two cow magnets? 2. were they placed N to N , similar pole to pole? 3. held together inside the pvc tube? 4. was the coil wrapped on a tube, like a spool of thread? 5. then this coil was slid over and centered where the two magnets = nearly touched? I would like pictures, how did it work? Thanks, Ted ----- Original Message -----=20 From: Mike Lozano=20 To: psnlist@................. Sent: Wednesday, August 11, 2010 8:35 PM Subject: RE: Faraday's Law Jim / Brett, =20 Thanks for the responses to my question. This afternoon I went to the = warehouse that's holding our household goods pending the building of our = retirement home in Lockhart. To make a long story short, I found the = Vertical Seismometer way back in a corner. I'll try to get back there = (I'll have to get some hired muscle to move boxes since I'm recovering = from a re-build (cadaver bone, 8 screws and 4 plates) surgery to my = knee) and take a picture of the gizmo, or take it apart for detailed = pictures. It may take me a week or two to get them. =20 To give a general idea of what it looks like; picture two =BD" thick = tubular magnets shoved inside of a 8" piece of 5/8" I.D. PVC. To force = them together, I cut the length of the PVC tube so that when end caps = were glued in place the magnets were shoved together, with only a slim = (.001") shim of Teflon holding them apart. Before gluing on the end = caps I placed a coil form with an I.D. of 5/8" . The coil form was = wrapped with as many turns of AWG #36 as I could put on the form. Then, = I located the midpoint of the magnet assembly at the midpoint of the = coil. Picture a donut sliding along a broomstick.=20 As I mentioned, I was just playing around when the idea came to me. = For those who aren't familiar with Cow Magnets, farmers make their cows = swallow them so that any metal they ingest while grazing will stick to = the magnets and not perforate their innards. Here's a link to the kind = of Cow Magnets I used: = http://www.magnetsource.com/Solutions_Pages/cowmagsAlnicoPill.html =20 Best regards, Mike =20 From: psnlist-request@.............. = [mailto:psnlist-request@............... On Behalf Of Jim and Connie = Lehman Sent: Wednesday, August 11, 2010 4:47 PM To: psnlist@.............. Subject: Fw: Faraday's Law =20 =20 ----- Original Message -----=20 From: Jim and Connie Lehman=20 To: psn-l@................. Sent: Wednesday, August 11, 2010 11:00 AM Subject: Re: Faraday's Law =20 Mike--an interesting question. N & S poles spaced apart create a = strong straight geometry of lines of force between them. N to N spaced = apart would show a "squished" field with lines of force leaving and = bending backward. A coil placed in a N to N setting would show some = output, but nothing like the N to S. Bear in mind, lines of force are fictitious but you get an idea of = their presence by placing a glass plate over N to S spaced closely, and = sprinkling iron filings over the area. Do likewise with N to N, and you = will see a big difference. In the typical Lehman coil/magnet arrangement the ideal is to place = half the pickup coil in the magnetic N to S gap so that the wires in = that part of the coil are perpendicular to the strong field lines. Then = any movement of coil or magnet will induce a current output from the = coil. Keep up the good work-Jim ----- Original Message -----=20 From: Mike Lozano=20 To: psn-l@................. Sent: Monday, August 09, 2010 7:43 PM Subject: RE: Faraday's Law =20 Hi everyone, =20 Here's a question I've always wanted to ask: Why (if the number of = magnetic lines of force cut per unit time produces a current flow) is it = not possible to force two identical magnets together so that they're = oriented (for example) N pole to N pole. It seems to me that the lines = of force would crowd together so that the least movement of them would = produce quite a strong response in a coil.=20 =20 I built a simple vertical seismometer with a 5 pound plumber's lead = as the weight, a spring and two cow magnets forced together in a tube of = PVC so that the resting position in the coil was the point at which the = maximum lines of force resided. It made a lot of sense when I designed = it but I didn't have a good environment in which to test it; e.g. A 500 = foot TV station antenna within 50 feet; an expressway two blocks away = and a location inside a TV studio. To be sure, it was a short period = sensor. =20 =20 I'm not a seismologist (that should be quite evident) . I'm a = retired electrical engineer who specialized in grounding and lightning = damage risk mitigation. In case you're wondering about the TV station = stuff, I made my living as a Meteorologist (my 2nd degree). If my idea = is dumb please excuse me - I was just very curious about this and = thought I'd write and ask. =20 Miguel Lozano Lockhart, TX, USA =20 From: psn-l-request@.............. = [mailto:psn-l-request@............... On Behalf Of Ted Channel Sent: Monday, August 09, 2010 9:36 AM To: psn Subject: Faraday's Law =20 Hi Folks, I have used a simple tubular coil and ring magnet assm. = in a number of sensors. Yet I still have unanswered questions about = Faraday's Law. =20 http://hyperphysics.phy-astr.gsu.edu/hbase/electric/farlaw.html I = have never taken the time to test all the configurations, but now is a = good time. Before I begin I wanted to ask someone, who understand it = or who actually has done these tests. =20 Here are my questions...............Looking at this wed page, there = is a simple, tubular coil. The illustration shows only one pole of the = magnet entering the coil. The formula and examples I believe I = understand. However What happens, when both poles are inside the = coil, say a small ring magnet 1/4" thick. Now things are not clear. = Is there a cancelling effect? With both north and south poles inside = the coil, I would think this would be the case. To keep this = understandable, let's not consider any magnets on the outside of the = coil. =20 I see these possibilities. =20 1 One pole entering the coil, as shown, when it move in one = direction it produces + voltage, when it move in the opposite direction, = - voltage. This is the only arrangement I have used. 2. Both poles inside the coil, when it move in one = direction.........? When it moves in the opposite direction....? 3. Two magnets, one entering and one exiting, with like poles facing = each other. When they move, at the same time, in one = direction..........? When they move, at the same time, in the other = direction? 4. Two magnets, one entering and one exiting, with opposite poles = facing each other. When they move, at the same time, in one = direction....? When they move, at the same time, in the other = direction? =20 I am going to run this simple test........but would like someone to = explain, before, what I should see. =20 Thanks, Ted

Mike, This is = interesting........I what to=20 see if I understand.

1. did you use two cow=20 magnets?

2. were they placed N to N , = similar=20 pole to pole?

3. held together inside the pvc=20 tube?

4. was the coil wrapped on a = tube, like a=20 spool of thread?

5. then this coil was slid over = and=20 centered where the two magnets nearly touched?

I would like pictures, how did it = work?

Thanks, Ted

----- Original Message -----

From:=20 Mike=20 Lozano

To: psnlist@.............. =

Sent: Wednesday, August 11, = 2010 8:35=20 PM

Subject: RE: Faraday's = Law

Jim=20 / Brett,

Thanks=20 for the responses to my question. This afternoon I went to the = warehouse=20 that=92s holding our household goods pending the building of our = retirement home=20 in Lockhart. To make a long story short, I found the Vertical=20 Seismometer way back in a corner. I=92ll try to get back there = (I=92ll have=20 to get some hired muscle to move boxes since I=92m recovering from a = re-build=20 (cadaver bone, 8 screws and 4 plates) surgery to my knee) and take a = picture=20 of the gizmo, or take it apart for detailed pictures. It may = take me a=20 week or two to get them.

To=20 give a general idea of what it looks like; picture two =BD=94 thick = tubular=20 magnets shoved inside of a 8=94 piece of 5/8=94 I.D. PVC. = To force=20 them together, I cut the length of the PVC tube so that when end caps = were=20 glued in place the magnets were shoved together, with only a slim = (.001=94) shim=20 of Teflon holding them apart. Before gluing on the end caps I = placed a=20 coil form with an I.D. of 5/8=94 . The coil form was wrapped = with as many=20 turns of AWG #36 as I could put on the form. Then, I located the = midpoint of the magnet assembly at the midpoint of the coil. = Picture a=20 donut sliding along a broomstick.

As=20 I mentioned, I was just playing around when the idea came to me. = For=20 those who aren=92t familiar with Cow Magnets, farmers make their cows = swallow=20 them so that any metal they ingest while grazing will stick to the = magnets and=20 not perforate their innards. Here=92s a link to the kind of Cow = Magnets I=20 used: http://www.magnetsource.com/Solutions_Pages/cowmagsAlnicoPill.html=

Best=20 regards,

Mike

From:=20 psnlist-request@.............. [mailto:psnlist-request@............... = On=20 Behalf Of Jim and Connie Lehman
Sent: Wednesday, August = 11, 2010=20 4:47 PM
To: psnlist@..............
Subject: Fw: = Faraday's=20 Law

----- = Original=20 Message -----

From: Jim = and Connie=20 Lehman

To: psn-l@..............=20

Sent: = Wednesday, August=20 11, 2010 11:00 AM

Subject: Re: = Faraday's=20 Law

Mike--an=20 interesting question. N & S poles spaced apart create a = strong=20 straight geometry of lines of force between them. N to N spaced = apart=20 would show a "squished" field with lines of force leaving and bending=20 backward. A coil placed in a N to N setting would show some = output, but=20 nothing like the N to S.

= Bear in=20 mind, lines of force are fictitious but you get an idea of their = presence by=20 placing a glass plate over N to S spaced closely, and sprinkling iron = filings=20 over the area. Do likewise with N to N, and you will see a big=20 difference.

In the=20 typical Lehman coil/magnet arrangement the ideal is to place half the pickup = coil in=20 the magnetic N to S gap so that the wires in that part of the coil are = perpendicular=20 to the strong field lines. Then any movement of coil = or=20 magnet will induce a current output from the = coil.

Keep up = the good=20 work-Jim

----- = Original=20 Message -----

From: Mike=20 Lozano

To: psn-l@..............=20

Sent: = Monday, August=20 09, 2010 7:43 PM

Subject: RE: = Faraday's=20 Law

Hi=20 everyone,

Here=92s=20 a question I=92ve always wanted to ask: Why (if the number of = magnetic=20 lines of force cut per unit time produces a current flow) is it not = possible=20 to force two identical magnets together so that they=92re oriented = (for=20 example) N pole to N pole. It seems to me that the lines of = force=20 would crowd together so that the least movement of them would = produce quite=20 a strong response in a coil.

I=20 built a simple vertical seismometer with a 5 pound plumber=92s lead = as the=20 weight, a spring and two cow magnets forced together in a tube of = PVC so=20 that the resting position in the coil was the point at which the = maximum=20 lines of force resided. It made a lot of sense when I designed = it but=20 I didn=92t have a good environment in which to test it; e.g. A 500 = foot TV=20 station antenna within 50 feet; an expressway two blocks away and a = location=20 inside a TV studio. To be sure, it was a short period = sensor. =20

I=92m=20 not a seismologist (that should be quite evident) =85 I=92m a = retired electrical=20 engineer who specialized in grounding and lightning damage risk=20 mitigation. In case you=92re wondering about the TV station = stuff, I=20 made my living as a Meteorologist (my 2^nd degree). = If my=20 idea is dumb please excuse me =96 I was just very curious about this = and=20 thought I=92d write and ask.

Miguel=20 Lozano

Lockhart,=20 TX, USA

From:=20 psn-l-request@.............. [mailto:psn-l-request@............... = On=20 Behalf Of Ted Channel
Sent: Monday, August 09, 2010 = 9:36=20 AM
To: psn
Subject: Faraday's=20 Law

Hi = Folks, I=20 have used a simple tubular coil and ring magnet assm. in a number of = sensors. Yet I still have unanswered questions about = Faraday's=20 Law.

= http://hyperphysics.phy-astr.gsu.edu/hbase/electric/farlaw.html = =20 I have never taken the time to test all the configurations, but now = is a=20 good time. Before I begin I wanted to ask someone, who=20 understand it or who actually has done these=20 tests.

Here are my=20 questions...............Looking at this wed page, there is a simple, = tubular=20 coil. The illustration shows only one pole of the magnet = entering the coil. The formula and examples I believe I=20 understand. However What happens, when both = poles are=20 inside the coil, say a small ring magnet 1/4" = thick. Now=20 things are not clear. Is there a cancelling=20 effect? With both north and south poles inside the = coil, I=20 would think this would be the case. To keep this=20 understandable, let's not consider any magnets on the outside of the = coil.

I see = these=20 possibilities.

1 One = pole=20 entering the coil, as shown, when it move in one direction it = produces +=20 voltage, when it move in the opposite direction, - voltage. = This is=20 the only arrangement I have used.

2. Both = poles=20 inside the coil, when it move in one direction.........? = When it=20 moves in the opposite direction....?

3. Two = magnets,=20 one entering and one exiting, with like poles facing each = other. =20 When they move, at the same time, in one = direction..........? =20 When they move, at the same time, in the other=20 direction?

4. Two=20 magnets, one entering and one exiting, with opposite poles facing = each=20 other. When they move, at the same time, in one = direction....? =20 When they move, at the same time, in the other=20 direction?

I am = going to run=20 this simple test........but would like someone to explain, before,=20 what I should see.

Thanks,

Ted

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