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Topic: Electronic Engineering Question |
Rick Collins
From:
Claremont , CA USA
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Posted 2 Sep 2015 10:33 am |
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I understand the electron and the magnetic field from the "physics" point of view.
The electron moves in the shell/shells of the atom.
An electromagnet can be made by running an electric current in a coil of wire.
Engineering Question:
Every pickup I've ever seen has a permanent magnet/magnets (pole, bar, horseshoe, etc.) plus the coil.
The field in which the string vibrates gets it's current from the amplifier.
SO:
Why does a pickup also need permanent magnets, since the current in the coil is already producing a field in which the string may vibrate?
Many thanks! |
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Robert Parent
From:
Gillette, WY
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Posted 2 Sep 2015 10:58 am
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<The field in which the string vibrates gets it's current from the amplifier.>
I'll disagree with that statement.... The permanent magnet is creating the magnetic field. The vibrating string is disrupting the field which is fed to the amplifier via the coil.
Robert |
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Michael Hummel
From:
Ottawa, Ontario, Canada
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Posted 2 Sep 2015 11:09 am
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Robert is right. There is no current provided by the amplifier to power the pickup. In theory this would be possible, but it is not too practical. Much easier to provide a nice, even magnetic field with (cheap) permanent magnets.
There are "active" pickups normally found only on 6-string guitars and basses, which use batteries to power impedance converters / amplifiers / tone circuits, but these still use permanent magnets to provide the magnetic field through which the strings cut.
Cheers,
Mike
_________________
MSA Classic 5+4
Too many 6-strings and amps to list |
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Scott Duckworth
From:
Etowah, TN Western Foothills of the Smokies
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Rick Collins
From:
Claremont , CA USA
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Posted 2 Sep 2015 12:03 pm
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Many thanks to all __ very clear and concise!  |
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