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From: roy@phri.nyu.edu (Roy Smith)
Newsgroups: sci.electronics
Subject: Re: power from phone line
Keywords: phone, power, remote
Message-ID: <1989Dec9.220311.15928@phri.nyu.edu>
Date: 9 Dec 89 22:03:11 GMT
References: <3542@kitty.UUCP> <548@scorn.sco.COM> <3547@kitty.UUCP>
Sender: news@phri.nyu.edu (News System)
Reply-To: roy@alanine.UUCP (Roy Smith)
Organization: Public Health Research Institute, NYC
Lines: 18

In article <3547@kitty.UUCP> larry@kitty.UUCP (Larry Lippman) writes:
> If you are going to design a commercial product, then you are in trouble
> because Part 68 will not allow ANY usable amount of leakage from tip to ring.

	Is this a new rule?  Universal Data Systems (now part of Motorola,
I think) used to make a nice little 1200 bps modem called the 212LP, where
the LP meant Line Powered.  We had a couple of them.  The power budget must
have been really tight because this was a real bare-bones unit.  No dialer
or auto-answer.  To call out, you had to dial the number yourself on a
phone then flip the talk/data switch on the front of the modem.  But it
definately didn't have any power supply.  I suppose it's possible that it
drew power from the RS-232 connection, but my impression was that it was
driven from the phone line.
--
Roy Smith, Public Health Research Institute
455 First Avenue, New York, NY 10016
roy@alanine.phri.nyu.edu -OR- {att,philabs,cmcl2,rutgers,hombre}!phri!roy
"My karma ran over my dogma"