At 04:38 PM 12/28/2010, David VanHorn wrote: >I have an existing system using a 2200uF 16V aluminum electrolytic as >energy storage, to keep a 3.3V processor running long enough to log >some data after the AC input has been removed. This works well enough >in the existing product which is designed for in-home use, but I have >been asked to redesign into an outdoor environment, and I will not be >allowed to use anything other than minimal passive temperature >control. Sanyo Oscon and their AX and GX normal electrolytic caps are rated=20 for use down to -55C. They also have extremely low ESR. I've been purchasing these directly from Sanyo USA because normal=20 distributors don't appear to handle them (or didn't, when we first=20 discovered them many years ago). Sanyo USA is actually pretty easy=20 to deal with. In other words, Sanyo makes a capacitor that should directly replace=20 your existing 2200uF 16V capacitor but works reliably down to below -55C. dwayne --=20 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 --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .