Yeah! An [EE] topic I can agree with! I've only ever seen one of these - pretty sure it was a fully-custom design. It was a LONG time ago - on some semi-pro audio gear (Shure mixer??) - don't remember. Sorry. Any chance you can jimmy something up using a slotted photo-interrupter? Some of the old phenolic open-frame RCA jacks I still have kicking around would allow this - the center contact doesn't fully enclose the plug's center pin and the pin protrudes past the contact by a full 1/8" or so. dwayne At 07:23 AM 4/14/2008, alan smith wrote: >I've been searching the normal places for a RCA type jack that has a >mechanical contact associated with it, such that I can detect when >someone plugs into it. These are pretty common for 1/8" mini and >such, but haven't found one yet that accepts the RCA plug. > > Anyone know of such a device? -- Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist