i have an idea of networking PCs using PLCC.

My questions are:
1. is it possible to modulate signals over a DC wave?
2. can we get the powerline signals after they are rectified?
3. What is the minium voltage/power required for PLCC transmission?

 

See this thread: http://www.control.com/1026213943/index_html

and this website: http://www.powerlinecommunications.net/whypowerline.htm

 

You might want to check the topic BPL (broadband over Power Lines) in Goggle, that is the project by many power companies to send high speed signals over their distribution netowrks. Home networking also has had some success in sending data and the IEEE is working on a communications standard.

From what little I know about this technique:
1. it does radiate the signals via the power lines you are using so security becomes an issue (maybe use of conduit will limit that issue).

2. Signal levels are limited (in the US) by the FCC part 15 coverage of unintentional radiators.

3. Electrical noise and transformers do limit the capabilities of the system to exchange data.

4. If you want to use DC distribution, the capacitors on the power supplies may filter the signal you want to send. USe of DC chokes might allow you to send the signals along the wires.

5. Distances typically reported before an amplifier is required is in the 1-2 kM length.

There is much more data available on the Internet - with some searching you will probably find some manafacturers and research to guide you. There is a lot of money chasing after this capability to distribute data over power wiring. Whether is becomes a large player along with EtherNet and other communications networks is still up for debate.

Regards,
Russ Kinner
Surprise, AZ USA

 

1. Yes. Automobile power-line technology, such as DC-LIN, sends data over the 12 V DC power line.
2. I doubt it.
3. I hear that the DC-LIN uses a (AC) signal roughly 10 V peak-peak. I hear that other powerline communication methods (HomePlug, etc.) use much less.

See
http://en.wikipedia.org/wiki/Power_line_communication
for many more details.