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Bone conduction transducers
Moderators: adafruit_support_bill, adafruit

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Bone conduction transducers

by thai_n_trinh on Sun Oct 08, 2017 11:27 am

Hello,
I've recently bought one of your transducers : https://www.adafruit.com/product/1674 and I've succeeded in transmitting sound to my head via bone conduction.
However, i'm doing my graduation thesis with this device so I am really in need of further information of this transducer:
1. Is this transducer piezoelectric ? If not, what are these made of and how do they work ?
2. Can I have the design pattern and the material of this transducer?
It would be a huge help if I can have these questions answered since my deadline is getting real close.
Please excuse my English since I'm not a native speaker.
Thank you very much in advance.
Regards,
Thai

thai_n_trinh
 
Posts: 3
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Re: Bone conduction transducers

by adafruit_support_bill on Sun Oct 08, 2017 12:20 pm

1 - It is not piezoelectric. It is a magnetic voice-coil motor. Much like a speaker - but without the cone. Instead, the vibrations are coupled to your skull.
https://en.wikipedia.org/wiki/Voice_coil
2 - We do not manufacture these in-house, so we do not have the design files for it. It has a steel frame, a copper coil and a permanent magnet. Those are the only details we have.

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Re: Bone conduction transducers

by thai_n_trinh on Sun Oct 08, 2017 2:08 pm

Thank you for your fast answers.
However, isn't bone conduction device is built based on piezoelectricity ? (which will vibrate when a voltage is applied)

thai_n_trinh
 
Posts: 3
Joined: Sun Oct 08, 2017 11:15 am

Re: Bone conduction transducers

by adafruit_support_bill on Sun Oct 08, 2017 2:12 pm

There may be some bone conduction devices that are designed that way. But this one is not. It is a magnetic coil. If you look closely at the device you can see the copper coil:

Image

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Re: Bone conduction transducers

by thai_n_trinh on Sun Oct 08, 2017 2:20 pm

Thank you.
These really help since I've messed up all my searching with "piezoelectric".
Again, thanks a ton !!!

thai_n_trinh
 
Posts: 3
Joined: Sun Oct 08, 2017 11:15 am

Please be positive and constructive with your questions and comments.