I forgot, in one of my last designs I used with success the ADUM isopower at 5KV isolation (very expensive as I mentioned before) http://www.analog.com/en/products/interface-isolation/isolation/isopower.ht= ml#isopower On Sun, May 17, 2015 at 12:50 PM, embedded systems wrote: > Harold, > opto couplers are a good idea up to 10KV isolation. Isolated supply at > 10KV it's usually expensive but up to 1KV it's easy to find: > > http://www.newark.com/recom-power/roe-0505s/dc-dc-converter-1w-5v-0-2a-si= p/dp/63X9545 > Buried cable is less susceptible to lighting. I will not be extremely > worried but depends what do you have at the end. > > Vasile > > > On Sat, May 16, 2015 at 8:39 PM, Harold Hallikainen < > harold@hallikainen.org> wrote: > >> I'm working on an application where contact closures will be sensed by a >> PIC inside a building, but the contacts are outside (perhaps tens of >> meters away). What sort of protection for the inputs is suggested? What >> sort of protection is required by regulatory standards for equipment >> connecting to outside wiring? The outside wiring would likely be buried, >> but lightning could still induce currents into buried cables. Opto >> couplers are one way to get the isolation, but then you have to power th= e >> LEDs with an isolated supply. Ideas? >> >> Thanks! >> >> Harold >> >> >> >> -- >> FCC Rules Updated Daily at http://www.hallikainen.com - Advertising >> opportunities available! >> Not sent from an iPhone. >> -- >> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> > > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .