AC (alternating current) lighting systems, in deck or porch applications, use a transformer that converts electricity to a 12 volt alternating current that is constantly switching polarity.
This means that the direction from which the current flows is changing back and forth.
Because of this, the polarity of the wires on the transformer, lights, and other in-line fixtures won’t need to be determined or kept in line.
It is recommended to check with the manufacturer to make sure any DC devices are designed to work long-term with AC devices, some may flicker, burn out, or not work at all.
