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Sub-Carrier Multiplexing

J

Jimbo

Jan 1, 1970
0
Does anyone have any ideas on how to place a signal on an AC line that
runs inside a 4,000 square foot house? Generally, how do you put the
piggybacked signal onto the line? (sub-carrier multiplexing) What is
the typical bandwidth on such a system? I'm interested in doing this
but I don't want to play around too much with an AC outlet too much.
I've heard about very simple systems that transmit two bits each cycle.
 
L

Luhan

Jan 1, 1970
0
Jimbo said:
Does anyone have any ideas on how to place a signal on an AC line that
runs inside a 4,000 square foot house? Generally, how do you put the
piggybacked signal onto the line? (sub-carrier multiplexing) What is
the typical bandwidth on such a system? I'm interested in doing this
but I don't want to play around too much with an AC outlet too much.
I've heard about very simple systems that transmit two bits each cycle.

Yes, its called X-10. Sold by Radio Shack and others for remotely
turning things on and off. They send multiple copies of each command
signal to improve the odds of one of them getting thru. Not exactly
reliable for sending data.

Luhan
 
J

Jimbo

Jan 1, 1970
0
I'm familiar with X-10, I was thinking about making my own interface
board, of course as long as I check to make sure there are no patents
 
M

martin griffith

Jan 1, 1970
0
Does anyone have any ideas on how to place a signal on an AC line that
runs inside a 4,000 square foot house? Generally, how do you put the
piggybacked signal onto the line? (sub-carrier multiplexing) What is
the typical bandwidth on such a system? I'm interested in doing this
but I don't want to play around too much with an AC outlet too much.
I've heard about very simple systems that transmit two bits each cycle.

have a look at the philips semicon site, they have/had some powerline
data ics.
The app notes had the calcs for the LC isolation circuits. Havent
investigated this for a coupleyears, so the chips may be in dodo land


martin
 
L

Luhan

Jan 1, 1970
0
Jimbo said:
I'm familiar with X-10, I was thinking about making my own interface
board, of course as long as I check to make sure there are no patents
on the technology. It's just for my hobby.

(please learn to bottom post)

For all practical purposes, patents only really apply to commercial
uses. You could model a system after the X-10 signals since they were
designed to propogate over the AC lines. Circuits for both sending and
receiving are available from Microchip among others.

Luhan
 
J

Jim Thompson

Jan 1, 1970
0
(please learn to bottom post)

For all practical purposes, patents only really apply to commercial
uses. You could model a system after the X-10 signals since they were
designed to propogate over the AC lines. Circuits for both sending and
receiving are available from Microchip among others.

Luhan

You can even make an *exact* copy of an X10 device for your own use.

The defining law concerns itself with *profiting*.

For instance, until fairly recently, it was perfectly legal to build
your own cable decoder box. The cable companies ultimately convinced
state legislatures to make laws defining theft of cable *service*.

...Jim Thompson
 
J

John Fields

Jan 1, 1970
0
I'm familiar with X-10, I was thinking about making my own interface
board, of course as long as I check to make sure there are no patents
on the technology. It's just for my hobby.
 
J

Joerg

Jan 1, 1970
0
Hello John,

However, X-10 is a rather crude AM protocol. Carrier on/off. I am using
it since about five years and I am not enthused, would never use it for
anything beyond convenience functions. It only works when it wants to.
Turn on the margarita blender and it chops up all the commands along
with the ice cubes.
 
J

John Fields

Jan 1, 1970
0
You can even make an *exact* copy of an X10 device for your own use.

The defining law concerns itself with *profiting*.

---
And, as such, if the intent of making the copy is merely to enjoy
the benefits of the invention without paying the owner of the patent
their just dues, that's prohibited.

However, building a copy for study, without payment to the owner of
the patent, is allowed, in the hope that that study will lead to
advancement in science and, ultimately, the betterment of mankind.
---
For instance, until fairly recently, it was perfectly legal to build
your own cable decoder box. The cable companies ultimately convinced
state legislatures to make laws defining theft of cable *service*.

---
Was that a bad thing?

Your electric company spent a lot of money to run copper all the way
from their alternators to your home, the deal being that (usually)
you wouldn't have to pay for the copper to be run, but that you'd
pay for every watt-hour you used, and that they'd make their money
on the come.

The cable company does the same thing with coax, but invoices
differently.

The intent is the same, however, and that's to provide you with a
service for which you agree to pay.

If you build a Zbox in order to fool the watt-hour meter into
thinking that you're you're using less energy than you are, then
you're a liar and a thief.

Same thing with the cable company.

Check with your wife.

Since she's Jewish, she'll know the difference between right and
wrong.
 
J

Jim Thompson

Jan 1, 1970
0
Wrong! I've had lengthy discussions with my patent lawyer over this.
You have to *profit* in the *sale* sense to infringe. "Enjoyment"
only counts with cable TV converters because of their cable-specific
laws.
However, building a copy for study, without payment to the owner of
the patent, is allowed, in the hope that that study will lead to
advancement in science and, ultimately, the betterment of mankind.

No. I was just pointing out that factoid.
Your electric company spent a lot of money to run copper all the way
from their alternators to your home, the deal being that (usually)
you wouldn't have to pay for the copper to be run, but that you'd
pay for every watt-hour you used, and that they'd make their money
on the come.

The cable company does the same thing with coax, but invoices
differently.

The intent is the same, however, and that's to provide you with a
service for which you agree to pay.

If you build a Zbox in order to fool the watt-hour meter into
thinking that you're you're using less energy than you are, then
you're a liar and a thief.

In that case you *are* using the device to steal something. With X-10
your use doesn't steal anything.
Same thing with the cable company.

But not patent infringement with "build-one" of anything else for your
own use.
Check with your wife.

Since she's Jewish, she'll know the difference between right and
wrong.

My wife is not Jewish, she simply has a biblical name. However my
daughter-in-law (Duane's widow) is Jewish.

But I know right from wrong... it's alright to tar and feather a
leftist weenie, but not a Republican ;-)

Might be alright to tar and feather Texans as well ;-)

...Jim Thompson
 
J

Joel Kolstad

Jan 1, 1970
0
John Fields said:
Was that a bad thing?

Because it would have been far better if they had spent all the money they
handed to lobbyists to get the law passed to instead just put decent crypto
into their cable system in the first place. Not to mention it would have
been just as easy to *contractulally* disallow cable TV descrambling -- why
in the world do we need a *law* regarding it?
The cable company does the same thing with coax, but invoices
differently.

The usual argument is that, "if there's a signal on my line, unless you,
say, want to *contractually* only let me use some of it, I should be able to
do with it what I want" -- can you imagine the power company charging you a
different price for the electricity to run that margarita blender of yours
vs. light bulbs? I'm sure someone would like that idea, and with today's
technology it could certainly be done.

Truth me told, though, I'm a lot more disgusted with the legislation that
made it illegal to intercept AMPS cell-phone calls than anything having to
do with cable TV -- this strikes me as a law that mainly had the effect of
delaying truly secure wireless phone calls for consumers. Thanks a lot!

---Joel
 
J

Jimbo

Jan 1, 1970
0
Mr. Thompson, please consult an attorney before you follow your own
advice.
 
J

John Fields

Jan 1, 1970
0
Hello John,


However, X-10 is a rather crude AM protocol. Carrier on/off. I am using
it since about five years and I am not enthused, would never use it for
anything beyond convenience functions. It only works when it wants to.
Turn on the margarita blender and it chops up all the commands along
with the ice cubes.
 
J

John Fields

Jan 1, 1970
0
On Thu, 15 Jun 2006 19:23:48 -0500, John Fields

Wrong! I've had lengthy discussions with my patent lawyer over this.
You have to *profit* in the *sale* sense to infringe. "Enjoyment"
only counts with cable TV converters because of their cable-specific
laws.

---
Nope. Tell your lawyer that he needs to get over to:

http://www.uspto.gov/web/offices/pac/mpep/documents/appxl_35_U_S_C_271.htm

and read:


"35 U.S.C. 271 Infringement of patent.

(a) Except as otherwise provided in this title, whoever without
authority makes, uses, offers to sell, or sells any patented
invention, within the United States, or imports into the United
States any patented invention during the term of the patent
therefor, infringes the patent."

Seems pretty clear to me...
---

No. I was just pointing out that factoid.


In that case you *are* using the device to steal something. With X-10
your use doesn't steal anything.

---
True, but I thought you were advocating copying an X-10 box for
personal use thinking the patent was still in force. Weren't you?
---
But not patent infringement with "build-one" of anything else for your
own use.

---
Wrong. Go to:

http://www.uspto.gov/web/offices/pac/mpep/documents/appxl_35_U_S_C_271.htm

and read it for yourself.
 
C

Clifford Heath

Jan 1, 1970
0
John said:
Nope. Tell your lawyer that he needs to get over to:
http://www.uspto.gov/web/offices/pac/mpep/documents/appxl_35_U_S_C_271.htm
and read:
"35 U.S.C. 271 Infringement of patent.
(a) Except as otherwise provided in this title, whoever without
authority makes, uses, offers to sell, or sells any patented
invention, within the United States, or imports into the United
States any patented invention during the term of the patent
therefor, infringes the patent."
Seems pretty clear to me...

Not to me, not without reading what is "otherwise provided
in this title".
 
J

Jim Thompson

Jan 1, 1970
0
John,

You confuse* written law with case law. Find me a one-off that was
successfully prosecuted... unless, of course, its use committed a real
"crime", such as stealing cable "services".

* As most people do who are not regularly involved in patent
litigation, as I am.

...Jim Thompson
 
J

Jim Thompson

Jan 1, 1970
0
Bwahahahahaha!

The USPTO has become a national joke... they'll issue Letters Patent
to anything that walks in the door.

And "35 U.S.C. 27" *wasn't* created by the USPTO.

Also, the USPTO doesn't enforce patent law.

...Jim Thompson
 
J

John Fields

Jan 1, 1970
0
You confuse* written law with case law. Find me a one-off that was
successfully prosecuted... unless, of course, its use committed a real
"crime", such as stealing cable "services".

* As most people do who are not regularly involved in patent
litigation, as I am.

---
**** you, you arrogant ass. No one was talking about case law; the
claim you made was that it's legal to copy an invention for
personal use.

It isn't, you were wrong, and puffing yourself up isn't going to
change that.
 
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