Hardware for vibration purpose

[mr_embedded]

Hi,
I'm currently trying out a new habilitation theory. What I want is a vibrator that can stimulate my skin with a frequency range of 4-400 Hz. I also want to be able to controll the intensity (power) of the vibration. A requirement is that the device (module) is quite small (like the ones in cellular phones.). I've searched alibaba.com etc. but can't find any devices that fulfills this frequency range. Does anyone have any suggestions about what device to use?

Over and out,
/ mr_embedded

 

[shrtrnd]

That's pretty low freq.
Try the surplus people at All Electronics Corp in CA.
They sometimes stock small vibrators from end of production runs for toys that vibrate, pager vibrators, and things like that.
They're on line, and if you ask, they'll put you on their mailing list for regular catalogs.

 

[(*steve*)]

A problem with using a motor to produce the vibration is that the only control you have is over speed.

The power delivered is dependant on the speed, so you cannot control power independently of frequency.

 

[mr_embedded]

Thanks for replying;

"Try the surplus people at All Electronics Corp in CA". That is a good start, will call them later, but since I live in Sweden I will try to find some closer supplier.

"so you cannot control power independently of frequency" yes.. I agree, but is there no vibration actuator with variable mass distance (from center axis to mass center of the weight)?

 

[(*steve*)]

Well, if you could find a small speaker with a fairly long throw, you might be able to affix a mass to the cone and drive it using a variable amplitude, variable frequency signal.

 

[mr_embedded]

*steve*: Yes, that would probably be a good solution but I would rather buy produced stuff than making my own since the goal is to make a product realization later on.

It has come to my awareness that the requirements are maybe not possible to meet hece I hace change them a bit;
Frequency range: ~100-250 Hz
Intensity: Controllable
Size/design: a flat design in preferred, height shall not exceed 15 mm.

Does anyone know a good supplier/retailer of a ready to use module for this purpose? I am grateful for all ideas and replies.

Thank!

 

[(*steve*)]

Unless there is a need somewhere else for such a device, then it won't exist.

Do you know what direction you want the vibration (normal or parallel seem to be the obvious options).

 

[mr_embedded]

Yes, "parallel" vibration is preferable.

 

[(*steve*)]

In that case, maybe you can find some small solenoid and connect a mass to that. If it is fixes securely inside an enclosure, all you need to is send it an appropriate AC signal and it should vibrate.

Who knows, you may not even need the additional mass (as the minimum frequency rises, the need for additional mass will reduce).

 

[shrtrnd]

Piezo element?
I've seen several interesting configurations in different types of devices.
Might be too fragile for intense vibration you might be considering though.
Just another idea to consider.

 

[shrtrnd]

Edmund Scientific catalog has some unusual items, that might work in your application.