At 04:35 AM 9/21/2009, David Duffy (AVD) wrote: >With the 78L05, the idle current draw from the 24V supply was about >4.7mA. Swapping it out for an LM2931-5 regulator dropped that to about >1.4mA, quite an improvement as the relay is off most of the time. I'm not sure how much improvement in quiescent current consumption you will see, but do consider the LP2950. Its my favorite low-power regulator. Part of that is its extremely good initial accuracy - I use it as the a/d reference for those applications that can't use ratiometric measurements. We used to use the LM2931 many years ago but have switched to the LP2950A or LM2941. The newer parts are just better, quieter, easier to use. Warning: don't forget to use the appropriate output capacitor when using any of these LDO regulators. dwayne -- 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