LM317 not good for much over 1A, is noisy under 100mA, and should probably not be used unless next to load. The band-gap ref is a hoot if you can live with its weirdness such as osc at some temps, poor response to load cap, and the Zout is varies very much with load changes. I suppose this is true for all 3-terminal regs. LM723 may require a little more work, but they are more apt to behave and not cause problems. Probably better off with a ref, an op amp, and base drive for some 3055s as series-pass.
Another trick for linear reg noise is the 'noise shunt'. This thread brings back many memories... Brian -----Original Message----- From: [email protected] [mailto:[email protected]]On Behalf Of Ted Eckert Sent: Friday, November 18, 2011 10:54 AM To: [email protected] Subject: RE: DC Supply If you can't find anything, look at application notes for the LM317 adjustable regulator. There are plenty of designs out there for adjustable linear power supplies. It will be quite inefficient, but you don't need to meet energy efficiency regulations if you are just building something for in-house testing. You might consider looking at electronics surplus stores. They may have some old linear adjustable supplies available. Ted Eckert Compliance Engineer Microsoft Corporation [email protected] - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://product-compliance.oc.ieee.org/ Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
