); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY From: Tom Clifton <[EMAIL PROTECTED]> Subject: [time-nuts] Parallel voltage regulators Date: Wed, 24 Oct 2007 16:33:08 -0700 (PDT) Message-ID: <[EMAIL PROTECTED]>
Tom, > A question for those that might know (or have an > opinion)... I have in hand an LPRO rubidium reference > that requires 1.7 amps at 24 volts while the oven > warms, dropping to 500ma while it runs. > > Can I parallel three or four 7824 TO220 style 1 amp > regulators with a quarter ohm half watt equalizing > resistor on the output of each one? I would not do that, even with the equalizing resistors. The load-balancing with resistors works when there is a common control-loop, but here you would have four inter-connected control-loops. It is not that hard to acheive 2 A at 24 V after all. The old uA723 and variants would probably do the trick good enought for you with external transitor(s). I recommend to at least include fold-back for over-current protection, but adding an over-voltage in form of a crow-bar setup isn't too hard either. The point of the crow-bar is to cause fold-back and if that fails, blow the fuse, so include a fuse on the unregulated supply side. Powerbalancing can be very tricky indeed, and you might end up with either one having the full load or oscillative behaviours. Cheers, Magnus _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
