I undertand 12v relay now. How about 110v relay for home use?
 

Is there a 110v relay to serve the same purpose as the 12v relay for home use?

what do you need to do?

ok, my dad got a sensor light in the backyard with some high wattage bulbs, which works fine. He put in some "energy saving" bulb which consumes less engery. The bulbs work fine for his purpose but when the light is off, I still can see it illuminates. Which makes me think the circuit is somehow leaking. If I can do something such as adding the relay, then I can avoid the leak? and also serve me the purpose of adding another bulb at another area of the backyard.
Am I correct?

I would check the wiring at the switch. It might be backwards. I noticed this once at my parent's house with LED Christmas lights. The switch was wired backwards and the ice, snow, and water was providing enough of a ground for the LEDs to work dimly. By the way, I have no idea what wired 'backwards' means. It's what my dad said just before he re wired it.

See if the switch is breaking neutral instead of hot. ( Maybe that is backwards ) .
If there will be power at the device to ground when the switch is off if it is wired incorrectly.
It can be confusing to change at the switch box if you are not familiar with the way power works.
Relays are available in a variety of amp ratings and coil voltages.
You can look at them at most HVAC online dealers.

The simple answer to your question is yes.

check the voltage at the light socket witha multimeter (MM). also check for voltage neutral to ground. recheck wiring

The sensor likely uses a triac to switch the light off and on. It has some leakage current that shows up on the high efficiency bulb, but doesn't show up on a regular filament style bulb. I would ignore it and work on my Porsche.

Thanks guys, I will take a look in the circuit, and will ask again before I make any change on the wiring. Again, thanks.

Porsche_monkey,
I think this is exactly what it does, small leakage. Is there a simple fixed, instead of wasting the energy? That is what I am wondering.
Thanks.

In short, no. The cost is negligible. Forget it.

A different bulb, or a relay. Neither is worth the effort in financial terms.

+1
Have a timer on my outside garage lights for dusk-dawn type operation. Changed the bulbs to flouresecnts and have noticed a slight glow when they're 'off'.
I figured triac leakage and ignore it.

Yep. Check the wires and if its correct, then leave it alone. Most of them are throw away items. They only last for so long.

Just remove the current control circuits and install a photocell from home depot.. may run you 5-10 bucks...

another problem I just found. The unit has 2 modes: 1 is for night only, and 1 is for day and night. When it's set to day/night, it works both day and night. When it set to night only, then it works great at night, but during the day, the light is always on :lol:.
Does this ensure that the wire are "backward"?

What is the photocell?

Compact Fluorescent Lights have a large inductor in them to filter the high frequencies switched to the tube and increase the power factor. It sounds like the inductor is not letting the triac shut off.

There is ususally some warning on the bulbs not to use with a dimmer.

Thanks Rick, I'll try the normal bulb and will post result.

you are right, it's also the Compact Fluorescent Lights problem, regarding the issue that the light didn't turn off during the day. It's all ok now after the high watange bulbs go back in.
Thanks.

From an electric consumption standpoint it may be cheaper to just disable the photocell and run the CFLs 24 hours a day

What is the CFL?

Compact Fluorescent Lights