carrier current transceivers

[lamnak]

Hey guys, I would like a simple circuit that can remotely turn a light on and off using the ac lines in the house.

 

[Sceadwian]

You can purchase these in stores for a price low enough that it's not worth making your own. If you're learning it's not adviseable to start with mains powered projects. There are more than a few circuits on the Internet that will do what you would like if you take the time to search for it on Google.

 

[lamnak]

Well i have been toing around with the small projects for a while now and decided to try mains voltage. I just want to see the concept and actually make one for myself. I have found some on the web but the are all for 220 volts. i would like to make a 120 volt transceiver that basically turns off and on a buzzer and light.

thanks

 

[Sceadwian]

Generally speaking if a switching circuit can switch 220volts it can also switch 120.

 

[unclejed613]

i know i have one of the old 150khz carrier current intercoms in one of my early 60's circuit books. all you would need to add would be an audio tone generator at the transmitter end and a tone decoder at the receiver end to switch a relay (or even better an SSR, since all that requires is a logic level).. it's really not complicated, the transmitter and receiver are just standard AM or FM circuits capacitively coupled to the power line. the only difference is that they operate at 150khz instead of one of the broadcast bands.

 

[lamnak]

Thanks to everyone for the input, I have built this project Mains Remote-Alert - RED - Page56
I have however found out that harmonic noise on the line affects its performance. Is there any way of altering this design so it can control two separate relays?

 

[unclejed613]

build a second pair with C3 in each equal to 1nF