Pickup Theory!

[rjb]

In my most simple words: Having the grounded part of the coil inside makes the PU insensitive to inference injection by touching the poles. This makes sense especially for strat type PUs.

Agree.

Not necessary for HB coils as their poles are typically grounded anyway.

Nitpicking:
In my limited experience with commercial "PAF style" HBs and knockoffs thereof, continuity between the poles and the backplate (and thus the shield wire) is actually hit-or-miss.
I've "experimented" to remedy this possible non-problem, using pieces of guitar string as springy serpentine bus wires, but did not collect measured data to show whether it really made any difference.

On the other hand, Ray Butts' "Filtertron" patent does show a backplate with springy contacts to make positive contact with the poles.

[Helmholtz]

In my limited experience with commercial "PAF style" HBs and knockoffs thereof, continuity between the poles and the backplate (and thus the shield wire) is actually hit-or-miss.

I know, but the close proximity to grounded parts also helps. Even better using soldered covers. Apart from that HB poles don't usually stick out like stratpoles, so the chance to touch them with your fingers is strongly reduced.

[Dolmetscher007]

Maybe this further explanation helps to understand the HB -PU principle

I LOVE these kinds of answers. They are difficult as hell for me to digest, but at least I get the feeling that you are really "on the pulse" of what I am asking. So, let me try to digest this...

1.) "The external AC magnetic interference fields are not [influenced by] the static magnetic polarity of the PU cores."
-- Just to be clear: "AC magnetic interference fields" refers to magnetic flux created by alternating current products by something one's immediate environment other than the pickup's own alternating current magnetic flux. This could be an electrical outlet nearby, a lamp, a radio, or anything else that uses alternating current creating magnetic flux. Correct?

2.) Thus the phase of the induced interference signal only depends on the electrical phase of the coils.
-- Just to be clear: So are you saying, since the interfering signal is not affected by the pickup's magnetic field, the phase of the interfering signal depends only on the phase of the coils?

These first two sentences are a bit complex. I am not sure what you mean when you say "The external magnetic interference fields are not influenced by the polarity of the pickup." The pickup does not influence or change the incoming interfering signal. But it does pick up the interfering signal and transduces it into the current/voltage, and finally into sound (noise).
And in sentence 2, I cannot tell if you are saying that... the phase of the interfering signal depends ONLY on the phase of the pickup's coils,... or if you mean, "only the phase of the interfering signal depends on the phase of the coils. And when you say "Phase of the coils" do you mean, clockwise vs. counter clockwise in relation to each other, or do you mean N-up vs. S-up magnets?

3.) The string signal, however, is produced by an amplitude variation of the static flux through the coils caused by the moving string.
-- Just to be clear: The string produces sound by pushing and pulling against and through the magnetic flux that otherwise is just standing still. This movement in the magnetic flux causes the electrons in the copper wire to be pushed and pulled... which basically is AC current. i.e. a signal.

4.) As the static flux flows in opposite directions in the 2 coils, increasing flux magnitude (caused by the string approaching the PU) means more positive flux through one coil and more negative flux through the other and 2 identical coils will produce inverse signal polarities at their respective ends.
--Just to be clear: Since one coil is wound "clockwise" (let's say) and the other is wound "counter-clockwise," when the string's movement disrupts the magnetic flux, which pushes electrons through the copper wire of the coil, the electrons are moving in one direction in one coil, and the exact opposite direction in the other coil.


5.) To get a net output voltage with the series wired coils, one of the coils needs to be wound or connected out of phase.
--Just to be clear: Since adding a positive current to the equal negative current = zero... one of the coils in a humbucker must be connected out of phase.
----------------------------

I guess I still don't understand how one connects a coil out of phase.

For a single-coil:
If I have a coil that was wound clockwise and it has 6 pole pieces, all with N facing up. That coil would have two wire-ends. I connect each of these wires to it's own brass eyelet on the pickup. Then I connect a wire to each of these eyelets, and connect those two wires to the + and - terminals of a guitar's output jack.

QUESTION: I am not sure which wire should be connected to the + and which to the - of the output jack; the inner-most "starting wire" or the final "end wire".
QUESTION: Does it completely not matter if N or S is facing up or down? No matter which direction (CW or CCW) the pickup was wound?

For a Humbucker:
You wind a single coil, just as above, and then you wind a second single coil. Then you somehow have to connect these two coils. I'd have to know the answer to my above question about which is + or - before I can really ask which wire from coil 1 is connected to which wire from coil 2, and I'd also need to know about N-up vs S-up with respect to winding direction.


MAN... this stuff does get complicated once you start to dig in.

Thanks for all your help Helmholtz and everyone else!

[Helmholtz]

I LOVE these kinds of answers. They are difficult as hell for me to digest, but at least I get the feeling that you are really "on the pulse" of what I am asking. So, let me try to digest this...

1.) "The external AC magnetic interference fields are not [influenced by] the static magnetic polarity of the PU cores."
-- Just to be clear: "AC magnetic interference fields" refers to magnetic flux created by alternating current products by something one's immediate environment other than the pickup's own alternating current magnetic flux. This could be an electrical outlet nearby, a lamp, a radio, or anything else that uses alternating current creating magnetic flux. Correct?

2.) Thus the phase of the induced interference signal only depends on the electrical phase of the coils.
-- Just to be clear: So are you saying, since the interfering signal is not affected by the pickup's magnetic field, the phase of the interfering signal depends only on the phase of the coils?

These first two sentences are a bit complex. I am not sure what you mean when you say "The external magnetic interference fields are not influenced by the polarity of the pickup." The pickup does not influence or change the incoming interfering signal. But it does pick up the interfering signal and transduces it into the current/voltage, and finally into sound (noise).
And in sentence 2, I cannot tell if you are saying that... the phase of the interfering signal depends ONLY on the phase of the pickup's coils,... or if you mean, "only the phase of the interfering signal depends on the phase of the coils. And when you say "Phase of the coils" do you mean, clockwise vs. counter clockwise in relation to each other, or do you mean N-up vs. S-up magnets?

3.) The string signal, however, is produced by an amplitude variation of the static flux through the coils caused by the moving string.
-- Just to be clear: The string produces sound by pushing and pulling against and through the magnetic flux that otherwise is just standing still. This movement in the magnetic flux causes the electrons in the copper wire to be pushed and pulled... which basically is AC current. i.e. a signal.

4.) As the static flux flows in opposite directions in the 2 coils, increasing flux magnitude (caused by the string approaching the PU) means more positive flux through one coil and more negative flux through the other and 2 identical coils will produce inverse signal polarities at their respective ends.
--Just to be clear: Since one coil is wound "clockwise" (let's say) and the other is wound "counter-clockwise," when the string's movement disrupts the magnetic flux, which pushes electrons through the copper wire of the coil, the electrons are moving in one direction in one coil, and the exact opposite direction in the other coil.


5.) To get a net output voltage with the series wired coils, one of the coils needs to be wound or connected out of phase.
--Just to be clear: Since adding a positive current to the equal negative current = zero... one of the coils in a humbucker must be connected out of phase.
----------------------------

I guess I still don't understand how one connects a coil out of phase.

For a single-coil:
If I have a coil that was wound clockwise and it has 6 pole pieces, all with N facing up. That coil would have two wire-ends. I connect each of these wires to it's own brass eyelet on the pickup. Then I connect a wire to each of these eyelets, and connect those two wires to the + and - terminals of a guitar's output jack.

QUESTION: I am not sure which wire should be connected to the + and which to the - of the output jack; the inner-most "starting wire" or the final "end wire".
QUESTION: Does it completely not matter if N or S is facing up or down? No matter which direction (CW or CCW) the pickup was wound?

For a Humbucker:
You wind a single coil, just as above, and then you wind a second single coil. Then you somehow have to connect these two coils. I'd have to know the answer to my above question about which is + or - before I can really ask which wire from coil 1 is connected to which wire from coil 2, and I'd also need to know about N-up vs S-up with respect to winding direction.


MAN... this stuff does get complicated once you start to dig in.

Thanks for all your help Helmholtz and everyone else!

I am willing to answer all questions in detail, but this requires the application of some basic physics principles. I am not sure if this is welcome here in the Beginner/Hobbyist section. Any advice T?

[rjb]

On a typical HB, both coils are wound CCW.

Just to elaborate:
Both coils are wound CCW but they are connected finish-to-finish. (It would also work if they were connected start-to-start.)
The key is to follow the current path through the pickup- and note the change of direction from one coil to the next.

[Chuck H]

Right. I thought all this was covered pretty well (with T's correction to my post ) The coils are indeed WIRED out of phase, but not wound to do so, just connected that way. If that makes sense.

[Chuck H]

WRT noise, that is the "hum" that humbuckers buck. Anything that can introduce a magnetic flux to a single coil will create a signal at the pickups output. So lamps, motors, dimmers, etc. are heard through the pickup relative to the strength of the noise. Now, if you have two coils side by side so that they "hear" nearly the same noise you will have a nearly equal signal from both coils. Now revers the phase of one coil and you have an opposite signal in one coil. When combined the opposite signals cancel each other. AND...

This is independent of the standing magnetic flux in the coils introduced by the magnet. In the case of the standing magnetic flux in a humbuckers coils, each is opposite, BUT, the coils are also connected in opposite phase. So changes that happen to both coils standing magnetic flux will be in phase and not cancelled.

[Dolmetscher007]

My advice is no physics, or deep theory here.
Not to be devils advocate, my questions are.
When are you doing the following.
1.build winder
2. wind basic single coil kitl
3 wind basic humbucker kit
Most questions will be self answered in the process.
Dive into the theory after you learn the basics.
The theory and physics needs to be kept in the main pickup area.
I'm not that big into theory, just enough to know they work and basically how they work, and how to make them sound like I want.
T

It would probably help if I explained my larger picture situation. I get the impression that I am coming off here as stubborn and wants to run before he learns to walk... or wants to be a rockstar before he even plays his first bar. Neither of which are the case.

I work in software, professionally. But I have been an avid woodworker and "maker," to use a new buzz word, in my free time for most of my life. I have also played the guitar since I was 11 years old, and I'm almost 41 now. A friend of mine asked me if I had ever tried to make a guitar, since it seems logical that I would have by now. It lit a fire in my belly to build a guitar. Of course, one thing lead to another in my mind, and I found that contrary to what you might think, the woodworking aspect of building a guitar is cool and all, but I discovered that I have a huge curiosity and desire to learn about how the electronics of a guitar works... mostly the pickups.

So... Here I am, 3-months into my "I'm going to build my own guitar, completely from scratch!" project. I have learned over my life that it is not always the most effective way to solve any problem to just start at the beginning, do something until it is done, and then move on to the next task. When you have a lot of new skills to learn, it helps to practice as many of the new skills as you can along the way. So... I decided, that since I have never painted, bound, and clear-coat finished a guitar before... I thought... well I'll practice on the pickup winder.
So, I have built a gorgeous pickup winder. I've bound it using cream ABS binding, and it is shaping up to be the Les Paul of pickup winders. Ha ha ha...!!!

But... it has drawn out the, "just build the damn pickup already!" process a little longer than I had anticipated. But, I have a few more things I need to do to my pickup winder before I can get started. I have already purchased a StewMac single-coil strat-style pickup kit with Alnico 5 mags. I bought 42 awg poly wire, and I bought a B&K Precision 388B Digital Multimeter, and a Weller WES51 analog soldering station with rosin flux core soldering wire. So I am all ready to go once I get the pickup winder finished.

I will say... I do anticipate a few set backs with the winder, but that will side-track this thread for sure.

So... in closing... Helmholz, please... drop all the physics and theory on my that you can. I am fully aware that the real education starts once one actually gets their hands on whatever they are learning about. But... right now, I am in a bit of a holding pattern, and I don't see any need in sitting around just whistling and kicking pebbles while I wait. Plus... I love physics, and I would want to know all this stuff even if I never touched a guitar again in my life. Coding software pays the bills, but I really wish I could just learn for a living. :-)

[rjb]

That is the purpose of the diagram.

Yea, I know. We're all using different words and illustrations to say the same thing. Sometimes it just takes the right combination to make a concept "click". I was just saying in words what is shown in the diagram.

[eschertron]

I've been following this thread with interest, maybe I can give you the 2nd-year physics dropout perspective (Maxwell kicked my @$$).

Magnets and coils can be thought of as a simple vectors. View CW winds and N magnetic poles as positive, CCW and S poles as negative. The resulting signal from a N magnet in a CW (N times CW, or N*CW) coil is positive, as is a S pole in a CCW wind. This S*CCW is the "RWRP" (reverse wound reverse polarity) middle single coil found in modern strats.
Since any EM field in the area - like 60Hz hum - affects the coils dynamically in phase, it is considered "common mode" noise and is cancelled out by the two out of phase coils. Please note that the magnets do not play a role in this interaction, only the coils. The currents induced by the magnets interacting with the vibrating strings are out of phase, because those currents are generated by the magnets. The vector results of the induced current, though, add because their vectors (N*CW, S*CCW) are both positive. Therefore, "hum bucking". Did I explain that well?

[Helmholtz]

So... in closing... Helmholz, please... drop all the physics and theory on my that you can.

Well, some members get repeatedly criticized for using physical terms and concepts at least in this section of the MEF. I am fed up with this.

Two proposals:

1) Start a new thread in the main PU area about PU principles and post your remaining questions, one after the other. Please understand that formulating profound answers in English means effort from me.... And/or

2) as you know German, try to find Prof. Zollner's awesome book "Physik der Elektrogitarre" and study the chapters about PUs.

[big_teee]

Since this thread no longer seems to have anything to do with cutting alnico, I will move it to the main area.
It's turned into a theory thread, and no pickups are being wound!

[nosaj]

It would probably help if I explained my larger picture situation. I get the impression that I am coming off here as stubborn and wants to run before he learns to walk... or wants to be a rockstar before he even plays his first bar. Neither of which are the case.

I work in software, professionally. But I have been an avid woodworker and "maker," to use a new buzz word, in my free time for most of my life. I have also played the guitar since I was 11 years old, and I'm almost 41 now. A friend of mine asked me if I had ever tried to make a guitar, since it seems logical that I would have by now. It lit a fire in my belly to build a guitar. Of course, one thing lead to another in my mind, and I found that contrary to what you might think, the woodworking aspect of building a guitar is cool and all, but I discovered that I have a huge curiosity and desire to learn about how the electronics of a guitar works... mostly the pickups.

So... Here I am, 3-months into my "I'm going to build my own guitar, completely from scratch!" project. I have learned over my life that it is not always the most effective way to solve any problem to just start at the beginning, do something until it is done, and then move on to the next task. When you have a lot of new skills to learn, it helps to practice as many of the new skills as you can along the way. So... I decided, that since I have never painted, bound, and clear-coat finished a guitar before... I thought... well I'll practice on the pickup winder.
So, I have built a gorgeous pickup winder. I've bound it using cream ABS binding, and it is shaping up to be the Les Paul of pickup winders. Ha ha ha...!!!

But... it has drawn out the, "just build the damn pickup already!" process a little longer than I had anticipated. But, I have a few more things I need to do to my pickup winder before I can get started. I have already purchased a StewMac single-coil strat-style pickup kit with Alnico 5 mags. I bought 42 awg poly wire, and I bought a B&K Precision 388B Digital Multimeter, and a Weller WES51 analog soldering station with rosin flux core soldering wire. So I am all ready to go once I get the pickup winder finished.

I will say... I do anticipate a few set backs with the winder, but that will side-track this thread for sure.

So... in closing... Helmholz, please... drop all the physics and theory on my that you can. I am fully aware that the real education starts once one actually gets their hands on whatever they are learning about. But... right now, I am in a bit of a holding pattern, and I don't see any need in sitting around just whistling and kicking pebbles while I wait. Plus... I love physics, and I would want to know all this stuff even if I never touched a guitar again in my life. Coding software pays the bills, but I really wish I could just learn for a living. :-)

So you say you've built the pickup winder bought all the stuff an now your not finished with the winder?
Which is it?

nosaj

[Dolmetscher007]

So you say you've built the pickup winder bought all the stuff an now your not finished with the winder?
Which is it?

nosaj

huh?

[nosaj]

huh?

Go back and read your post You say you built it and then a few sentences later say you haven't finished it.
thats what.
nosaj