12VAC

[JoeNorm]

Why are landscape lights commonly 12VAC? Why is DC not used here as much? Adding more characters now so the post will go through. Thanks

 

[retirede]

Probably due to cost. Back in the day, a simple transformer was cheaper than a power supply with rectifiers. Nowadays with switching power supplies and the rising cost of copper, that may no longer be true.

 

[SceneryDriver]

The likely reason is cost - diodes just added cost to the power supply, and the incandescent lamps (and now LEDs with internal rectifiers) are perfectly happy on 12VAC. The other reason may be electrically driven corrosion. Landscape lighting isn't exactly a bastion of good installation practices (wirenuts buried in the wet dirt, etc...) and a DC voltage will preferentially corrode the positive conductor with regards to the negative conductor. With AC, it balances out every half cycle.

A real benefit to DC is that there is no flicker/strobing, especially with LED. I know I can often see a strobing effect on LED Christmas lights when they move through my field of vision, especially in a dark room.


SceneryDriver