Why doesn't a guitar pickup's top and bottom cancel itself out? [closed]

Question

A guitar pickup is a coil of wire with some magnets in the middle. The magnets magnetize the steel guitar strings. When those strings a strummed, they vibrate, and since they're magnets they induce a small current in the coil. So far so good.

Let's assume the coil is wound clockwise, and it is a single coil pickup.

When the string moves right, it causes current the flow right. On the top part of the coil, that means clockwise, but in the bottom, that means counter clockwise.

Should those two opposite currents cancel out to zero?

As the string quickly moves left and right, each time its pulling the electrons in that direction on the top and bottom parts of the loop. And if its a middle string it probably doesn't affect the sides of the coil much.

So guitar pickups shouldn't work. But they definitely do. What is wrong with my explanation?

This question probably applies to most transducers.

Answer 1

Your explanation with the top and bottom induction seems to be somewhat off.

The guitar string is part of the magnetic circuit comprised of:

• the magnet
• the string
• the air between and around

This magnetic circuit channels some magnetic flux through the coil.

When the string vibrates, the amount of flux going through the coils changes, because the magnetic circuit changes.

This flux change causes a proportional induction voltage between the coil terminals. The induced current is therefore equal in the entire coil.