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From: jgb@prism.gatech.EDU (James G. Baker)
Newsgroups: sci.electronics,comp.sys.ibm.pc.hardware
Subject: RS-232 powered modems
Message-ID: <19983@hydra.gatech.EDU>
Date: 20 Jan 91 22:55:56 GMT
Followup-To: sci.electronics
Organization: Georgia Institute of Technology
Lines: 14

I've seen small 2400 baud modems that *only* have COM and phone connections.
How do these pull power from the telephone or computer?  I need to make a 
box with similar needs (a few LS parts) and of course they need a +5 power
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?

Thanks!


-- 
BAKER,JAMES G - Undergraduate Lab Instructor, School of Electrical Engineering
____  _    _    Georgia Institute of Technology, Atlanta Georgia, 30332
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(_|. |_). |_).  Internet: jgb@prism.gatech.edu