John Walshe wrote:
>Hi guys,
>    I've a weird one here that I've been racking by brain with. I need to
>generate a vibration that is detectable by a human as a small tickle -
>equivalent to a spider/insect crawling on your foot. My problem is that I've
>only got 3V to work with from a coin cell(or 2) i.e. zilch current!. Also it
>will be driven by a PIC running from the same battery so low power
>consumption is of utmost importance.
>
>I've been playing with piezo elements - I'm waiting on some housed elements
>to be delivered to see if the resonant soundbox helps.
>
>The proposed application area would prohibit the use of a cellphone
>vibrating battery so that is discounted.
>


Hi John,

There are little vibrators available for pagers, but I don't know
the electrical details.

Re piezo elements, I should think that would work. If you
connect one to a PIC at 5v, and pulse it, the volume is
loud enuf to drive you out of the room. I use a 100-1000 ohm R
in series to limit volume. 3v might be ok for skin vibrations.

Also, be aware that these things will sing perfectly well at
frequencies down as low as 100-200 hz and up to 10 khz, despite
what the "resonant" frequencies are touted as. At the low-end,
you might get nice vibrations without too much volume.

hope this helps,
- dan michaels
www.oricomtech.com
==========================

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics