multiplex 8 singles on to AC power line

[chameleon121]

multiplex 8 signals on to AC power line

Im trying to find an inexpensive way to take 8-24vac control signals (either on or off) and multiplex them digitally to be transmitted over a 100 foot 24vac power line and then de-multiplex on the other end back to 8 24vac lines to run relays. I was thinking of using res/caps on each line to give a noisy DC level to input into MID400 optoisolators where it would mutiplex into some sort of encoder/transmitter and then receiver/decoder at the other end into optoisolator Triacs. I am not sure what to use as the encoder or how to couple to the 24vac line. Anyone have any ideas?

Thanks

 

[Ubergeek63]

Why?

Are you supplying 24VAC power to far end, or just control signals?

If you are supplying power, can you use DC at the far end?

If not, why are you using AC relays at the far end? And why not just supply a low level control signal?

Dan

 

[chameleon121]

Im looking for a way to expand HVAC thermostat controls to use existing wiring. The 24Vac transformer on the heating unit supplies the power to the termostat so I dont think I can get around the 24 vac thing since everything in the industry uses it. I would like to be able to put in any new thermostat with more accessories with a simple TX/RX system and be able to control up to eight items just over the oringal 2 or 4 conductor cable.

 

[lasvegasmale31]

If the cable is 4 conductor, could you use 2 conductors as your 24vac power supply that is existing and then the other 2 conductors as communications wires? but then there might be an issue with interference. Just a thought.