Vibrate a string with electricity? Best ways?

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    Electricity String
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Discussion Overview

The discussion centers around the feasibility and methods of vibrating a string using electricity, particularly through the use of electromagnets. Participants explore various aspects including the type of strings (metallic vs. non-metallic), frequency considerations, and the mechanics of electromagnetic actuation.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant proposes that an electromagnet could vibrate a string if it is pulsed at the fundamental resonant frequency, questioning the efficiency of different frequencies or waveforms.
  • Another participant asserts that an electromagnet will not affect a string unless it physically contacts it, suggesting that the interaction is limited without direct impact.
  • A later reply mentions a project where electromagnets are used to actuate strings on a piano, implying practical applications exist but providing limited information on broader uses.
  • One participant clarifies that for metallic strings, a changing magnetic field is necessary to induce vibration, stating that oscillating current (not necessarily at resonant frequency) can cause movement.
  • Another participant references an EBow as a device that vibrates strings electrically, sharing a personal experience with its use.

Areas of Agreement / Disagreement

Participants express differing views on the effectiveness of electromagnets in vibrating strings, with some supporting the idea under specific conditions while others contest its feasibility without physical contact. The discussion remains unresolved regarding the best methods and conditions for achieving string vibration electrically.

Contextual Notes

There are limitations in the discussion regarding the assumptions about string materials, the specifics of electromagnetic field variations, and the lack of detailed experimental evidence or references beyond the mentioned piano project.

MauriceWaves
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Is it possible to vibrate a string with electricity? I'm guessing an electro-magnet placed close to the string would be able to vibrate it.

If the electro-magnet is used to vibrate the string, I'm guessing the electro-magnet should be pulsed at the fundamental resonate frequency of the string? Maybe different frequencies or harmonic intervals are more efficient? And I wonder should the electro-magnet be fed a sine-wave or is some other wave more appropriate to excite the string?

Also is there anything that would tell me where the most efficient placement of the electro-magnet would be?
 
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As far as I know, an electromagnet will do nothing to string. Absolutely nothing, unless you physically hit the string with the electromagnet.
 
UncertaintyAjay said:
As far as I know, an electromagnet will do nothing to string. Absolutely nothing, unless you physically hit the string with the electromagnet.

Here's a project where electro-magnets are used to actuate strings on a piano.

http://music.ece.drexel.edu/research/mrp/actuation

Unfortunately I haven't been able to find much else on the internets.
 
Ohhhh, you're talking about metallic strings, I was thinking of the rope thingies. In that case yeah. But you have to vary the field of the electromagnet. Doesn't have to be resonant frequency though. As long as you have a changing magnetic field, you'll move the wire. So, if your current to the electromagnet oscillates( like a.c , which is sinusoidal, but it doesn't have to be), the string will vibrate
 
MauriceWaves said:
Is it possible to vibrate a string with electricity? I'm guessing an electro-magnet placed close to the string would be able to vibrate it.

An EBow is one such device:

https://en.wikipedia.org/wiki/EBow

I used one a few years ago, great fun.
 

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