Inhouse audio distribution

[Rodney]

Some time back I saw a project that let you put the audio from any source such as TV, radio, Phono etc. on the AC lines in a dwelling and then a second unit that could be plugged into any outlet on the same AC distribution and reconstitute the audio. Any one remember the source of that project or can recommend one that is not to expensive to construct?

[MrAl]

Hi there,


National Semiconductor has an app note on this product. I dont remember the app number but you can search on the National site and it should turn up something. If you cant find it let me know and i'll look through my old notes to find it.
I believe it's from around 1975 and was made to demonstrate one or more of their chips.

It's not the simplest thing in the world to build though, as the transmitter is a modulator that modulates a 200kHz carrier
and pumps that into the line, while the receiver is a demodulator and amplifier. There is some line impedance matching going
on too with some transformers if i remember right.

I found the app note, it is app note AN-146. It uses two special coils made by TOKO who's data sheet can be found
also on the web. Note sure where to purchase these though.

[Rodney]

Thanks for the info Mr. Al, I appreciate the response. RodneyYou need to a flashplayer enabled browser to view this YouTube video

[MrAl]

What video?

That app note is in .pdf form so Acrobat Reader will allow viewing it.