12v-120v relay

[JasonB]

I know there has to be a simple way to accomplish what I am trying to do.

I have some 12v low voltage landscape lighting around my house. These lights are powered/controlled by a LV transformer that has a built in photo sensor + timer. Ie, it comes on at dark for 3 hours. I also have a 110v outdoor lamppost that plugs into a standard grounded outlet. I would like to have a relay that can turn the lamppost on/off when the LV lighting goes on/off. Seems it should be a simple off-the-shelf relay to do this, but I can't wrap my head around it at the moment. Essentially, when there is 12v present, 110v ac flows.

Can someone point me to such a relay?

 

[stevenj]

Re: 12v-120v relay

http://www.functionaldevices.com/


http://www.functionaldevices.com/pdf/RIBU1C.pdf


How about these

 

[ThumbPkr]

Re: 12v-120v relay

What you will need is a SPST relay with the contacts rated for the voltage/current that your 110 volt lamp will draw.It is common practice to double the ratings of the relay contacts for your expected usage.
The pull in coil for the relay will be 12 volt coil powered by the LV line that turns your low voltage lights on.This can all be done in the house as long as you can access the 110 volt line that supplies the lamp post and the low side of the transformer that drops line voltage down to 12 volts for the LV lighting.Make the connection on the lamp side of the switch that controls the lamp post.Ron G

 

[patrickray]

Re: 12v-120v relay

You could convert your 110v lamp to low voltage. Just make sure you dont go over your transformer wattage.

 

[JasonB]

Re: 12v-120v relay

Hmm.... Could I change the bulb to one of these:

http://www.lightbulbsdirect.com/page/001/PROD/LandIncanLowVolt/25FMCL12V

and just let the transformer power it? I still have about 35w of 12v left.

 

[patrickray]

Re: 12v-120v relay

all though it dont say low voltage. I think it would work. You just have to re-wire your lamp holder. If you have a duel place on your transformer to run leas of off. Run just one lead to the lamp. But I dont think it will be that bright.

 

[patrickray]

Re: 12v-120v relay

I forgot to mention and clicked reply before I thought about edit.
Anyway, They do make low voltage lighting for lamp post that you are refering to.

 

[triumphrick]

Re: 12v-120v relay

Good posts to date, and keep in mind that you will want to use a "bell box", weatherproof plastic junction box with a rubbergasket cover. I like using a 4x4 box with (2) conduit entrances on the same side. I use one of them with a short piece of conduit to bury the wiring. I make the other longer and a dummy pipe that is used to elevate the box off the ground.

 

[bandit86]

Re: 12v-120v relay

a rgular 12V relay from your car will work. if you go to the auto wreckers, you can even snip the harness out. if not, there is actual 12v relays you can buy