); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY From: Bruce Griffiths <[EMAIL PROTECTED]> Subject: Re: [time-nuts] Parallel voltage regulators Date: Thu, 25 Oct 2007 13:51:47 +1300 Message-ID: <[EMAIL PROTECTED]>
> ); SAEximRunCond expanded to false > Errors-To: [EMAIL PROTECTED] RETRY > > Magnus Danielson wrote: > > 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. > > > > Cheers, > > Magnus > > > Hej Magnus > > Using a 723 correctly configured with a low pass filter on the reference > is a very low noise regulator solution with its output noise at least > 20dB lower than that produced by a typical 3 terminal regulator. > > Most of the OEM open frame linear supplies use 723 regulators with > external (to the 723) series pass transistors. > These regulators have varying degrees of sophistication, some even use a > zener plus emitter follower preregulator for the LM723. > Some foolishly omit bleeder resistors across the reservoir capacitors > which can lead to damage when making connections after powering the > supply on and then off as the residual energy stored in the reservoir > capacitors is more than sufficient to destroy the 723 should the output > terminals be shorted. While the 723 isn't the highest degree of sofistication these days, it does alow for building more or less complete linear regulators. In another hobby of mine they are in plentiful use and provide stable enought regulation. 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.
