Subject:
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Re: sending signals over power lines
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Fri, 27 Dec 1996 18:03:49 GMT
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Original-From:
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Tom G. Brusehaver/Consultant Euler Solutions <tgb@bnu003.NOMORESPAMcncc.bnr.com>
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Reply-To:
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tgb@bnr^stopspammers^.com
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Viewed:
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1514 times
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> Now what I am wondering, is how exactly is this done? How are the signals
> encoded? Is AC required or can this be done over DC as well? I'm
> interested in doing something similiar, just not with appliances and house
> current.
There are a bunch of proposals along these lines (eia standards, and
future standards) CeBus, LonWorks. X-10 is most prevelant, somewhat
limited, and some of the stuff sold is of marginal quality, although
some is really good.
X-10 is what you get at Radio Shack, and with the IBM Aptiva computer.
It relies on AC for it's signaling. It uses the Zero crossing for a
sync, and modulates a message in the first couple microseconds after
that.
Phone wires already carry a multitude of signals, including dialtone,
ring, and the analog voice signals. Ring is a 90V signal, normal
dialtone is about 48V (yikes this could be really off? my memory is
fading, something about on hook is 48v off hook is 12V). To through
in another modulation scheme accross these wires would be possible,
but a challenge (is ring going to be received as a pile of noise,
possibly damaging all units on the same wire?). To be totally legal,
you will need an FCC part 95 approved DAA (data access arangement) to
connect your product to the phone lines running to the CO.
Of course you could build a PBX using the handy board, and use the
phone wires for sending messages to LCD displays around the house or
something.
If you question is 'can I build a private network using simple twisted
pair wires?' then the answer is yes, check out RS-485, CAN, IIC, or
any other similiar networks.
--
tgb@bnr.com
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Message is in Reply To:
 | | sending signals over power lines
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| hello. While this question doesn't pertain directly to the handyboard, I thought I would post it here since I am using the handyboard in my project. Some of you may have heard of this product: There are devices on the market (radio shack and a few (...) (28 years ago, 27-Dec-96, to lugnet.robotics.handyboard)
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