1800-Watt Outdoor Post Mount Button Dusk-To-Dawn Photocell, Black

A:  I don't understand "transfo for LED light"...

A:  I don't understand your question. Please make complete words so I can give you an accurate answer.

A:  Sunlight, or light from any source, triggers the sensor to turn off whatever light fixture it is connected to. If the sensor is attached to the collar of the post facing the morning sunlight and the post light is facing in the opposite direction, it might work.

A:  I'm not sure what you mean by "collar", but it is intended for post light mounting. As long as the clear sensor is not directly in view of the light, it should be fine.

A:  The pull is negligible. Otherwise, it would be cheaper to run lights, etc. 24 hours a day. You will be pleased with this unit, mine has been very dependable - replaced once in 10 years and likely due to a power surge.

A:  !800w is the downstream load it can handle with out failing. Power usage at idle is minimal.

A:  The power consume by it self is minimal and is depending on the load you connect to it (maximum load at 1800 watts). I had it connected to 2 LED porch lights at 6 watts each (equals to 40 watts regular light bulb) and stay on all night long , my power bill per month is about $30.00 (all LED lights).

A:  Yes, the device is suitable for that application.

A:  Yes, Let the Photo Cell control the power leg that supplies power to the bulbs. When there is no light power is supplied to the circuit for the lights to come on.

A:  Yes, it just needs to be connected in-line on the power wires before splitting to the 3 bulbs. (Ours switches 2 separate light fixtures, both from the same power source.)

A:  Yes