Overheating Coils with Audio Signal

[albatriana]

Hello Forum,

I'm working on a project that requires controling the frequency and amplitude of multiple string vibrators and the easiest way for me to do this is using audio signals controlled with a MAX/MSP (programing interface) patch.

I bought this device http://www.pasco.com/prodCatalog/WA/WA-9857_string-vibrator/, it consists of a copper coil, a rare earth magnet and an aluminium reed, I already made my home imitation (foto). Since this device is made to work with a 5V AC power adapter at 60hz I have the following problem:
- If I use an amplified audio signal the coil overheats.
- If I use a sine wave generator I'm unable to control the signal's frequency and amplitude from my computer, not to mention that I would need multiple generators to control each vibrator.

I've also got http://www.pasco.com/prodCatalog/WA/WA-9854_economy-wave-driver/, which is basically a loudspeaker with no cone and a reed to insert the string. This one does not overheat but it sounds loud and my project requires no sound or a soft sound. This would be my best solution but I need a way to get rid of the sound.
I am a musician and really don't know much about electricity or amplification, I would love to hire someone to help me build a device that meets my requirements or I wonder if any of you has any ideas or advice for me.


Thank you very much in advance

 

[foxhole]

Maybe try a music/electronic forum?

 

[jockscott]

The economy wave driver you (almost) link to is actually a 5, 1/4" sub woofer with a post to attach the string to. No wonder it sounds loud.

 

[mattylad]

try edaboard for something like this.

You will have more chance of someone being able to help you.

 

[albatriana]

@jockscott: Indeed it is, do you have any idea how could I get rid of the sound (or at least most of it)?

@mattylad: Thank you, I will certainly look there.

 

[albatriana]

bumping for a first and only time

 

[Sam Gangee]

At resonance, the power used should be very low - too low to heat the coil. So I'd suggest that your string length and/or tension were incorrect.

Anyway, your requirements are too vague.

How many strings?
What frequency (please list for each string)?
How are you generating the sine wave for each string at present?