[sdiy] How piezo's work

[Ken Stone]

Also from the Piezo Switch development site, and of more interest -

Some characteristics of Piezo switches are:

****- Make pulse time N.O.: typical 20-300 mS (depending on actuation rate)
- Typical actuation force: 4 - 32 oz. depending on actuation rate
- Switching current: 100 mA typical
- Switching voltage: up to l20V AC/DC
- Switching resistance "ON": less then 20 ohms
- Switching resistance "OFF": greater then 5M ohms
- No contact arcing or bouncing
- No mechanical wear ( for non-tactile feedback switches)

**** gives a pulse, not a level, which means either Peter doesn't have these
units, or there is some black magic going on....

Ken

>from the Piezo Switch development site:
>
>How Piezo switches work:
>
>Finger pressure is applied to the surface of the switch-housing surface to
>deflect about 2 microns. This pressure activates the Piezo crystal, which
>converts this to an electrical signal and the signal is amplified by
>electronics imbedded in the housing
>> 
>
>
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