Post by thread:[PICLIST] Subject: Re: [EE]: service life of rubbe

Roman Black <spam_OUTfastvidTakeThisOuTEZY.NET.AU> wrote: >I think the estimate of 200,000 times to 5% resistance is >a bit fanciful, we get many TV and VCR remotes that are worn to >failure within two years. I would say maybe 50,000 times to >failure or even worse. Actually as David has said, using gold plated fingers, a silicone (good quality) keypad and rigid keycaps in a sealed environment will make it last. BUT the price tag of all this will be higher than membrane or pushswitch keyboards for small sizes (as used on PIC projects). For large keyboards, it pays to go rubber. I am pretty sure that an amazing proportion of the piclist members type their messages on rubber-based keyboards (with keycaps and mechanical guides). One of the keyboards I liked for innovative design was the IBM portable computer's which was a Hall sensor keyboard with springs that caused a small magnet to stand or lie on the Hall sensor. The Hall sensor was printed directly onto the PCB using thick film technology ;-) These did fail sometimes (the mechanical part) but they were great fun to use. Peter -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! use .....listservKILLspam@spam@mitvma.mit.edu?body=SET%20PICList%20DIGEST