Path: utzoo!utgpu!watserv1!watmath!att!pacbell.com!ucsd!usc!zaphod.mps.ohio-state.edu!think.com!eplunix!raoul
From: raoul@eplunix.UUCP (Nico Garcia)
Newsgroups: sci.electronics
Subject: Re: RS-232 powered modems
Keywords: RS-232, Self-powered
Message-ID: <1010@eplunix.UUCP>
Date: 25 Jan 91 17:37:27 GMT
References: <19983@hydra.gatech.EDU> <2820@casbah.acns.nwu.edu> <2663@krafla.rhi.hi.is>
Organization: Eaton-Peabody Lab, Boston, MA
Lines: 16

>In article <19983@hydra.gatech.EDU> jgb@prism.gatech.EDU (James G. Baker) writes:
>>supply.  Is there a +5V line on RS-232C and is it standard with DB25 and DB9
>>connectors?  Or is there a +12,etc that I could feed into a voltage
>regulator?

Ummm, I'm looking at a listing of the EIA signals from a Maxwell modem right
here. It says pin 9 is +Testing Voltage, Pin 10 is -Testing Voltage. Now, if
the *terminal* is wired appropriately, there could indeed be a voltage source
there. I've got one of the old phone line modems, though, 1200 baud and
almost indestructible. I kinda like it. Runs off the "off-hook" current,
which is supposed to be about 10-15 volts across a 600 ohm telephone load.

-- 
			Nico Garcia
			Designs by Geniuses for use by Idiots
			eplunix!cirl!raoul@eddie.mit.edu