Most deck lighting systems require a transformer as a powersource that converts 110 volt line voltage to 12 volt low voltage electricity. The transformer will pluginto a standard outlet and run wiring through a loop to each light fixture. Some transformers use a timeror light sensor to automatically turn the lights on at night. It is very important to purchase the correcttransformer for your lighting system.  Most LED lights require 12 volt DC volt transformers while most incandescent lights require 12 volt AC transformers. Check the specifications on the lightfixtures before purchasing your transformer.

To determine the size of the transformer you need you willneed to multiply the number of lights by the number of watts and add 10% for line loss.

You will need to purchase a transformer that can supply atleast 220 watts. Round this number up tothe next available transformer size.