sending high frequency in phone line

[praveen]

Archived from groups: comp.dcom.lans.ethernet (More info?)

Hello,

I have an indicator (LED) (in some interfacing box) which is located
50 meters from my board.
Telephone signal is transmitted from My board to Interfacing box
through CAT-5 cable.

I get a Command from my processor to glow the LED.
Can i superimposing it with the telephone signal in the form of high
frequency signal (10 KHz)(which is generated on Processor LED glow
command) through the line which is decoded in the interfacing box,
which in turn glows the LED?

Or Is there any other good and cheap method of glowing the LED.



Thank you
Regards
Praveen

 

[Guest]

Archived from groups: comp.dcom.lans.ethernet (More info?)

praveen wrote:

> Hello,
>
> I have an indicator (LED) (in some interfacing box) which is located
> 50 meters from my board.
> Telephone signal is transmitted from My board to Interfacing box
> through CAT-5 cable.
>
> I get a Command from my processor to glow the LED.
> Can i superimposing it with the telephone signal in the form of high
> frequency signal (10 KHz)(which is generated on Processor LED glow
> command) through the line which is decoded in the interfacing box,
> which in turn glows the LED?
>
> Or Is there any other good and cheap method of glowing the LED.

You can use any "out of band" signal to operate that LED. All you need, is
the appropriate filtering to keep any audible signal out of the phone and
also interfering voice energy out of your device. In fact, it would
probably be best, select a frequency well above hearing range, to avoid
interference in either direction. Sub-audible frequencies could also work.
Then again, if you've got some spare pairs, why not use them?

 

[Guest]

Archived from groups: comp.dcom.lans.ethernet (More info?)

praveenkumar1979@rediffmail.com (praveen) wrote:
>I have an indicator (LED) (in some interfacing box) which is located
>50 meters from my board.
>Telephone signal is transmitted from My board to Interfacing box
>through CAT-5 cable.

>Or Is there any other good and cheap method of glowing the LED.

I'd use polarity inversion if I only had one pair to play with, but if
you've got Cat5, you've got four pairs, and you only need one for the
phone line....

 

[praveen]

Archived from groups: comp.dcom.lans.ethernet (More info?)

Hello William,
Yes i am using CAT-5 but i donot have spare line. I have ethernet data
(4 line) and 2 phone line (4 line) used in CAT-5.
Tell me how will you reverse the line?

Thanks and regards
Praveen

 

[Guest]

Archived from groups: comp.dcom.lans.ethernet (More info?)

In article <ff8a3afb.0411082320.396167be@posting.google.com> praveenkumar1979@rediffmail.com (praveen) writes:
>From: praveenkumar1979@rediffmail.com (praveen)
>Subject: Re: sending high frequency in phone line
>Date: 8 Nov 2004 23:20:56 -0800

>Tell me how will you reverse the line?

For example with 4 transistors bridge connected ...


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[Guest]

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praveenkumar1979@rediffmail.com (praveen) wrote:
>Yes i am using CAT-5 but i donot have spare line. I have ethernet data
>(4 line) and 2 phone line (4 line) used in CAT-5.
>Tell me how will you reverse the line?

If it's a real live actual phone line from the telco I'd probably use
a DPDT relay. (Most modern) Telephones are polarity insensitive, and
the handset current can probably even run the LED for you, just put it
in series with the phone line, and add a reverse diode to conduct when
you have the polarity inverted.