Path: utzoo!utgpu!water!watmath!clyde!bellcore!rutgers!gatech!hubcap!ncrcae!wte
From: wte@ncrcae.Columbia.NCR.COM (Bill Eason)
Newsgroups: sci.electronics
Subject: Re: Powering circuits from serial p
Message-ID: <3595@ncrcae.Columbia.NCR.COM>
Date: 25 Jul 88 12:36:42 GMT
References: <1712@iscuva.ISCS.COM> <44000014@pyr1.cs.ucl.ac.uk>
Reply-To: wte@ncrcae.Columbia.NCR.COM (Bill Eason)
Organization: NCR Corp., Engineering & Manufacturing - Columbia, SC
Lines: 34

In article <44000014@pyr1.cs.ucl.ac.uk> william@pyr1.cs.ucl.ac.uk writes:
=
=Yep, you can do this.  In fact I sucked power from everything coming in
=including Rx.  I had the RS232 inputs all pumping into a bridge
=rectifier...
<stuff deleted>
=I don't recall the exact spec, but I seem to recall that RS232 levels were
=defined as valid from (+/-) 3-12V.  I think.  I remember that I had to
=decide whether the above circuit should have to be designed around the fact 
=that levels may be as little as 3V.
=
=			... Bill
=
=************************************************************************
=Bill Witts, CS Dept.     *
=UCL, London, Errrp       *       Don't believe everything you hear,
=william@uk.ac.ucl.cs(UK) *       or anything you say.
=william@cs.ucl.ac.uk(US) ***********************************************


If you should try this, don't forget the voltage losses you will experience
across the diodes: 0.7V typ? x 2 = 1.4V across a bridge rectifier.  This would
only leave a minimum of 1.6V for your circuit.  

Just a thought...

		        ... Bill

*************************************************************************
-- 

Bill Eason   (803) 791-6419    ...!ucbvax!sdcsvax!ncr-sd!ncrcae!sauron!wte
NCR Corporation		  ...!rutgers!mcnc!ece-csc!ncrcae!sauron!wte
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