Mar 21, 2009 #1 F Fowler9 New member Joined Mar 21, 2009 Messages 7 Reaction score 0 Points 1 How do they change from green to red? is it automatic sensors or does someone watch with a camera?
Mar 21, 2009 #2 N Naren_RocksU New member Joined Mar 21, 2009 Messages 1 Reaction score 0 Points 1 They keep timers to set the time in that electronic equipment. And the lights work according to that time delay.
They keep timers to set the time in that electronic equipment. And the lights work according to that time delay.