In message <199906031722.KAA10068@mauler.srl.org>, Michael Shiloh
<michael@MAULER.SRL.ORG> writes
>I've toyed with this idea and I don't know if it's practical.
>Neither RF nor power transmission is my area of expertise, so
>forgive me if I am asking stupid questions.
>
>Suppose I have a situation where I want to send power and control
>signals to a device. Suppose too that I want to do this all with
>2 wires (power and return). Is it at all feasible to send the data
>on top of the power line, and have it separated at the destination?

It's quite easy to do, it's been done with aerial amplifiers for years,
the power unit sends DC up the coax, and the amplifier sends RF back
down. You just split it at either end with a simple filter, a capacitor
feeding the AC signal (which blocks the DC), and an inductor feeding the
DC (which blocks the AC). Obviously the values required depend on the
frequencies used, and the amount of DC power you are drawing through the
cable.
--

Nigel.

        /--------------------------------------------------------------\
        | Nigel Goodwin   | Internet : nigelg@lpilsley.demon.co.uk     |
        | Lower Pilsley   | Web Page : http://www.lpilsley.demon.co.uk |
        | Chesterfield    | Official site for Shin Ki and New Spirit   |
        | England         |                 Ju Jitsu                   |
        \--------------------------------------------------------------/