safrit@shumv1.ncsu.edu (John Safrit) (02/23/90)
I'm presently working on a research project that requires the output of a bandpass filter to be converted to a vibration that can be felt on the skin. I've used small speakers, but they don't produce a strong enough vibration. I've thought of using solenoids to transmit the vibration, but I don't know what kind would be useful. If anyone has any information about what kind of solenoid would give to desired effect, where I could get such, or any idea of what might work instead. You can e-mail to me or post to this group. Thanks! John Safrit ****************************************************************************** * Some say the worlds a stage, where we play our foolish parts, but it seems * * more like a cage, holding back our hungry hearts. ---me * **************************************************safrit@shumv1.ncsu.edu******
craig@oakhill.UUCP (Craig Shaw) (02/24/90)
In article <1990Feb22.185504.15032@ncsuvx.ncsu.edu> safrit@shumv1.ncsu.edu (John Safrit) writes: > > I'm presently working on a research project that requires the output of >a bandpass filter to be converted to a vibration that can be felt on the skin. >I've used small speakers, but they don't produce a strong enough vibration. > Try a small permanent-magnet DC motor with an eccentric on the shaft. I believe that is what is used on my pager, when it is operated in silent mode. Ideally the RPM should be tuned to the resonant frequency of the enclosure. The entire pager runs off of 1 AA battery, and is about 2 1/2" x 1 1/2" x 3/4". It also has an 12+ character LCD display, which even lights up! The heart of the system is a 68HC11 microcontroller. At about 3 pages/day the battery life is better than three months (Eveready alkaline). The point is, this can be done small, cheap, and low-power. Good luck. -- I'M THE NRA. Craig D. Shaw - MCU Systems Design (512)891-2245 Motorola Inc., Austin, TX.