Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!ut-sally!ut-ngp!jjr From: jjr@ut-ngp.UUCP (Jeff Rodriguez) Newsgroups: sci.electronics Subject: Choosing Cap Size in Power Supply Message-ID: <5705@ut-ngp.UUCP> Date: Sun, 26-Jul-87 22:39:35 EDT Article-I.D.: ut-ngp.5705 Posted: Sun Jul 26 22:39:35 1987 Date-Received: Mon, 27-Jul-87 03:46:07 EDT Reply-To: jjr@ngp.UUCP (Jeff Rodriguez) Organization: Dept. of Elec. Engr.; Univ. of TX at Austin Lines: 11 I'm building a general-purpose power supply based on a 12 V/450 mA transformer. The secondary feeds into a full-wave bridge rectifier, which feeds into an LM317T adjustable voltage regulator (1.2 V to 27 V output at 1.5 A). How do I choose the size of capacitor to place across the output of the rectifier? I once heard that the rule-of-thumb is 1000 micro-F per 1 A of current. Is that reasonable?