Dual Wire Wind? (Alternative to tapping/splitting)

[mcgruff]

Cunning plan: begin winding a coil with two strands of wire. After (say) 1/3 of the total number of turns, end one strand of wire and finish the coil with a single wire, as normal.

You now have two interleaved coils which you can connect in series for full power or "split" to 3/4 power (technically also 1/4 power although that option will likely sound horribly thin).

Anyone tried this? Maybe there are good, technical reasons not to which I'm not aware of.

[Helmholtz]

What would be the expected benefit compared to a tapped coil?

When you connect 2 coupled coils having same turns in parallel, nothing changes.
That's different from paralleling 2 independent coils, where inductance would be halved.

[mcgruff]

A better split sound with low-wind humbuckers.. maybe? A single coil on its own is usually too weak. This would let you set up a split sound which doesn't depend on the humbucker's coil size. Cut any number of turns of wire you like from each coil in the humbucker. And it would be fully humbucking.

[Helmholtz]

Please elaborate.
What configuration are you thinking of which wouldn't be possible with tapped coils?
A drawing would help.

[mcgruff]

This is what I was thinking of. Two coils on the right on one bobbin, two on the left on the other.

But I've over-complicated things. You don't need to run two strands of wire to achieve this. Just tap both coils. Doh!

Thanks for being patient. It helped me to clarify my thoughts.



Or this:

[Helmholtz]

Whenever you short many turns on a PU (as in your first pic), you're more or less killing the output.
Reason is the magnetic coupling like with a transformer

[mcgruff]

Thanks. The second schematic then, if I do this. That would mean either 6 wires to take to the control cavity from each pickup (!) or build switches into the pickup rings.

[Helmholtz]

But the second pic would give you the same results as with a humbucker having tapped coils.

[John_H]

Roland, do you think there could be significant capacitive coupling with two coils on the same bobbin?

[Helmholtz]

Roland, do you think there could be significant capacitive coupling with two coils on the same bobbin?

Hi John,
there will be some direct capacitive coupling between the coils but the major additional capacitive load would be due to reflected capacitance from the magnetic (or transformer) coupling.
The latter means that the sheer existence of a second coil on the same bobbin will increase the effective capacitance across the first coil even if the second coil is not used/connected.

[John_H]

Thanks Roland, and Hello back The capacitive coupling was the first though I had. That capacitance in concert with the reflected capacitance would create a high Q scenario. Any thoughts?