>It's generaly accepted that a ripple of less then 10% >has negigible impact on the performance of a TEC. OK, that will do me then. >Note that Maxim and Analog devices have high frequency >switching TEC controllers that can give low ripple with >very small inductor and capacitor values. Yeah, I'm needing to do it with Radiation Hardened devices though, as it is going to orbit the moon. If I use the "correct" device then I would be stuck with something around 50kHz!!!, based around a Rad Hard version of a UC1845. May yet just use a mil-spec one that is speced to go to 500kHz, as that was used for another purpose on a previous mission. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist