Can we use same "Power supply' line for data transmission.
Consider hotel having 50 rooms, now for room service customer will press bell/buzzer whatever is provided.
Now for 50 rooms normally, 50 separate cables/lines will be used.
Instead of that, we can use single line through which 'signal' can be sent to reception and reception will identify which customer/room is calling?

How to do?
One way wud be use different carrier frequencies, for room1 say 10kHz, room2 15kHz,...
With frequency identification we can identify which rooms is calling.

Same concept can be used various sensors. insted of separate line for each sensor, single line (power supply) will serve transmission purpose.


Now in telephones there is pair of cables, giving say 5V dc (i'm from India and i'm not sure of voltage also.)
The same cable which gives 5V DC carries voice information.
So concept is not that new actually.

Does anybody have any idea whatsoever regarding this project/concept ?
Please reply back as soon as possible.

I'm thinkin this as my final yr project. (I'm doing graduation/bachelors in eltrx and telecommunication , its pity despite this branch, i dunno telephone line vtg.!!!! )

Anyway plz reply back.
regards,
Neil.

__________________
Sometimes truth is stranger than fiction !!!

 

This application note pdf has a usefull little circuit for sending control signals and power on the same line, handles composite video as well.

Attached Files

video_mux-control.pdf (99.8 KB, 81 views)

 

For some reason I couldn't get the PDF file.

An alternative is the X-10 system switches OTS technology at about $10US a pop for each station ( http://smarthome.com/x10map.html) which gives you a wide margin of addresses. I'm envision a sort of monitoring station like the one's at a hospital . The patient presses a button and 4 hours later the nurse shows up (...err sorry recent hospital stay). You would see the indicator and reset it from the monitoring station.

Another alternative either as a new building or a remodel project where you can use a dedicated line ( 2 conductor cat 5 plenum cable) is the I2C buss by Phillips robust and cheap to work with. http://www.semiconductors.philips.co...cts/index.html

In the US you can just fish the wire over a drop ceiling ( as long as its low Volt) so no conduit issues.

 

i heard about broadband internet being tested on high tension wires between some states of USA.

 

right click on 'download' and click 'save target as'. For some reason if you just click on it, it doesn't work

 

Here's another little trick I got trawling the web.

Attached Images

figure_01.gif (15.8 KB, 322 views)

 

If You have a relative clean power line, maybe useable the "powerline intercom" (i've reverse engineered one from COMMAX) with DTMF modulation. ST have a powerline modem IC, but for this need some uC experience...