turns theory.....

[Rosewood]

Bill Lawrence has some patents for pickups with closed loops in them, either in the center or the outside of the regular wraps. His reasoning is it flattens out the resonant peaks in the coil. I bet he discovered this when he had a short in the coil.

I've wound a few that shorted on the steel blade. When I measured from the blade to the start of the coil I could see a small amount of resistance, usually several hundred Ohms. If I wanted to reproduce that coil I could probably wind to that resistance, connect those turns as a loop, and start a new coil on top of it.

So you might be able to determine an approximation of the shorted section by comparing the resistance of each coil.

Something to think about anyway.

That's interesting David, I wonder how many and where were the shorts.

[Possum]

patents...

do you have any of the patent numbers for that? Its an interesting idea, those little strat pickups with tiny coils can be real brigth so doing that would make alot of sense. I'd be interested in knowing exactly how he does it.

[corduroyew]

Bill Lawrence has some patents for pickups with closed loops in them, either in the center or the outside of the regular wraps. His reasoning is it flattens out the resonant peaks in the coil. I bet he discovered this when he had a short in the coil.

I've wound a few that shorted on the steel blade. When I measured from the blade to the start of the coil I could see a small amount of resistance, usually several hundred Ohms. If I wanted to reproduce that coil I could probably wind to that resistance, connect those turns as a loop, and start a new coil on top of it.

So you might be able to determine an approximation of the shorted section by comparing the resistance of each coil.

Something to think about anyway.

That is a good idea. Now I just have to decide it I want to try and get to the parts. It's all encapulated with epoxy now. I could carefuly pic away at it, but with luck something what it is, I'd end up with a broken coil rather than a short one. Sill, it's a good Idea. I'll try it one of these day. Thanks for the tip.

[Rosewood]

I wonder if it's the shorted turns or the gap that he's going for. I think he's into air coils isn't he? I mean several hundred turns would make a nice spacer, sorta.

[Joe Gwinn]

That is a good idea. Now I just have to decide it I want to try and get to the parts. It's all encapulated with epoxy now. I could carefuly pic away at it, but with luck something what it is, I'd end up with a broken coil rather than a short one. Sill, it's a good Idea. I'll try it one of these day. Thanks for the tip.

There is no need for the shorted turn or turns to be connected to the rest of the coil. Just wrap some extra turns around it, and short those added turns.

[David Schwab]

do you have any of the patent numbers for that? Its an interesting idea, those little strat pickups with tiny coils can be real brigth so doing that would make alot of sense. I'd be interested in knowing exactly how he does it.

5789691 is for a stack, and 5376754 is the closed circuit coil.

He also has 3711619, which uses coaxial coils.

[David Schwab]

I wonder if it's the shorted turns or the gap that he's going for. I think he's into air coils isn't he? I mean several hundred turns would make a nice spacer, sorta.

I haven't seen any air coils from Larwence since his acoustic pickups.

I'd like to see how he does those too.

[Possum]

application...

So, I haven't read the patents yet, but so you would wind a small coil and connect the end of that coil to the start of that small coil, then from the end of that small coil also connected to a new larger coil wound on top of it, is that correct? I"m trying to visualize how this would actually work in real life here. OK I'll go read the patents.

[Possum]

closed turns....

OK, so briefly he is winding another couple layers over his coil and this outer coil is closed and not connected to the primary coil at all? HOw does this work in physics terms? Is it the same as wind a piece of copper foil and connecting the ends over the coil, are are the turns of the outer closed coil killing high frequencies more than one turn of copper foil? Does the outer coil have more induced eddy currents because of more turns of wire than the single layer of copper foil?

[Rosewood]

OK, so briefly he is winding another couple layers over his coil and this outer coil is closed and not connected to the primary coil at all? HOw does this work in physics terms? Is it the same as wind a piece of copper foil and connecting the ends over the coil, are are the turns of the outer closed coil killing high frequencies more than one turn of copper foil? Does the outer coil have more induced eddy currents because of more turns of wire than the single layer of copper foil?

Is the shorted turns grounded? Maybe if we keep talking Bill will jump in and set us straight. I don't understand the shorted turns connected to nothing.

[Possum]

..

No its connected to nothing. Its a coil wrapped around the inner coil and the ends connected to itself, a closed loop. Maybe Joe Gwinn will tear himself away from his glass of port and turkey sandwich and jump in here. I have one problem pickup this might help out, otherwise its not a real useful trick overall. Useful for small stacked strat type stuff like he does, but then who wants their pickups to sound like Lawrences either.....

[Joe Gwinn]

Is the shorted turns grounded? Maybe if we keep talking Bill will jump in and set us straight. I don't understand the shorted turns connected to nothing.

Consider the Force. Given that a pickup senses the motion of strings through a few millimeters of air, why is a coil connected to nothing any odder?

No visible means of support is required. Nor is grounding, except to reduce electrostatic noise.

No it's connected to nothing. It's a coil wrapped around the inner coil and the ends connected to itself, a closed loop.

Exactly.

Maybe Joe Gwinn will tear himself away from his glass of port and turkey sandwich and jump in here.

Rum. Captain Morgan. Perhaps in eggnog, perhaps not.

[kevinT]

glass of port and turkey sandwich...

hehehe....what a combination

[Possum]

.....weirdness...

so WHY when overlaying a small coil on top of another one does it only squech the top end when that coil is CLOSED? Current flows in a closed coil? Can't quite figure out whats going on there but it does work....

[Joe Gwinn]

so WHY when overlaying a small coil on top of another one does it only squelch the top end when that coil is CLOSED? Current flows in a closed coil? Can't quite figure out whats going on there but it does work....

The equivalent of eddy currents flows in the closed coil, but cannot flow if the circuit is open.

Put thy faith in The Force, my son.