Yes you are right its a variable capacitor theres a very thin moving plate underneat its very hard to see.. it seems to be moved by some sort of diaphram below.. thanks.. "Alan B. Pearce" wrote in message news:018001c8b989$e7c45140$1979f682@space.rl.ac.uk... > >Yes, it looks like a pressure sensor, but perhaps it's >>some type of pressure switch? > > My reaction was it is a capacitor with the plate to plate distance > controlled by external pressure. The description of it going into a NOR > gate > suggests a CMOS oscillator that then has its frequency varied by the > capacitance change. > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist