Post by thread:Leaching PIC power from RS-232

<x-flowed>I've seen it done with pre-packaged products, but how can I leach enough power from RS-232 to power a F876? Thanks in advance John Craft John A. Craft (228)689-8100 Voice Lead Analyst (228)689-8130 Fax Diamond Data Systems of MS, Inc. http://www.diamonddata.com MSAAP Bldg 9110 spam_OUTjcraftTakeThisOuTdiamonddata.com Stennis Space Center, MS 39529 </x-flowed>

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 At 10:02 PM 3/31/00 -0600, John A. Craft wrote: >I've seen it done with pre-packaged products, but how can I leach enough >power from RS-232 to power a F876? In a production design? Look up the 232 spec, and find the minimum load spec. This will tell you how much current each connected driver must be able to source. Also, note that the drivers only have to develop 3V into this load. Use the highest impedance for your receivers you can, and pocket the change. :) In real life, they will do better than spec, but that's all the energy you can count on. It's a lot like phone line powered devices, you can only count on 20mA, and no particular voltage at all. This is a good excersize for those who skimp on their 232 interfaces to run through, as it helps illustrate that the "other guy" may need some of that margin too :) -----BEGIN PGP SIGNATURE----- Version: PGPfreeware 6.5.2 for non-commercial use <http://www.pgp.com> iQA/AwUBOOWhKIFlGDz1l6VWEQLMxACgxxtdJakDVVUNEFUkkSGwvgLFXyAAn2D8 s/9aPb0Bj+Vmq2esaoTKsJEj =hGkC -----END PGP SIGNATURE-----

see: http://techref.massmind.org/io/serial/parasitic --- James Newton .....jamesnewtonKILLspam@spam@geocities.com 1-619-652-0593 http://techref.massmind.org NEW! FINALLY A REAL NAME! Members can add private/public comments/pages ($0 TANSTAAFL web hosting) {Original Message removed}