May be you would like to share some of your sketches. Piezo-electric ??? I wonder how those childrens' shoes with blinking LEDs work. The LEDs blink when the sole contact ground. When the tool is at rest is there still 7bar pressure? CHL ----- Original Message ----- From: Morgan Olsson To: Sent: Thursday, April 13, 2000 2:50 PM Subject: Air powered electronics > I«m working on a project where the customer don«t want electric connection. > And no batteries needing to charge, switch or anything like that either.