Power on Coms?

[steveowens]

Does anyone know of any power on communications IC? I have DC power, and need to modulate a low speed digitial communication signal on it (like from a UART). I could dsign my own from PLLs and Drivers, but there must be a IC out there that does this? Have searched all the sites I know of, but come up empty.

Steve Owens
Finish Line Product Development Services

http://www.FinishLinePDS.com

 

[Lewish]

About 20 years ago Signetics came out with ICs for use in communicating over power lines. These generated many variants. Try searching on X10 and on "power line modem".
I think you will find there is lots of stuff out there.

 

[steveowens]

The x10 is for AC, will it work on DC as well?

 

[Lewish]

Why wouldn't it work for DC? The data signal is AC coupled to the wire (thru capacitors), so it doesn't matter what is on the wire as long as the AC on the wire isn't of a nature that will interfere with the X10.

I have used the original Signetics chips, before X10, on top of telephone voice communication. But if you put a modem on the phone line and it is active, the harmonics would kill my data stream. And a phone line is after all a DC line.

 

[steveowens]

OK Thanks, I thought the X10 transmitted when the zero cross ocured on the A/C. I'll check into it.

Steve Owens
Finish Line Product Development Services

http://www.FinishLinePDS.com

Steve.Owens@FinishLinePDS.com

 

[Lewish]

Steve, I am not sure, because I never worked with X10. But, I do know you can piggyback a datastream onto many wiring systems using AC coupling. Useable distance is a function of data carrier frequency. I have done 4000 feet easily at 10 KHz carrier.
Just make sure there are no coils in the line, and no capacitors across the line.
On some DC supplies, you may need a choke in each lead at the source to isolate you from a capacitor.

 

[jbartos]

Suggestion: Visit

http://www.e-insite.net/ednmag/archives/1998/010198/01di_08.htm

http://www.epanorama.net/links/psu_monitor.html

http://www.toshiba.co.jp/about/press/1999_12/pr1701.htm

http://www.mods.dk/log.php3

etc. for more info