Who and how are street lamps turned on?

Answer 1

They are turned on (in the US) by sensors that measure the amount of light. When the light level goes down (meaning it's getting dark outside) the sensor has a relay that will close and apply power to the light.

I have designed projects though that use timers as well.

Answer 2

A sensor which turns the lamp on as it gets to a certain light fade - that's why streetlamps under trees come on earlier.

And it costs circa 5p to run a street lamp per night.

Answer 3

Used to be by time but nowadays each lamp fitting has a light sensor that switches on as daylight fades.. Similarly switches the lamp off in the mornibg after sunrise.

Answer 4

Street lamps are turned on and off by a light sensor. This is done automatically.

Answer 5

By the lamp lighter who comes around on his bike early in the morning

Answer 6

Usually they either have a timer that tells them when to turn on, or they have a sensor that turned them on when it gets dark enough.

Answer 7

They have solar sensors on top, when they don't detect like [i.e. at night] they go on.
That's why some mornings, when it's dark but getting slightly brighter, they flick on and off.

Answer 8

They are on timers, which is why over the next month or so you will see lots of men on those high platform things changing the timers when the clocks change!

Answer 9

normally timers like you see the little timer boxes you can plug into an outlet at home and plug in certain items when your on vacation. or they have light sensitvie eyes when it gets so dark they come on and when its so light they go off.

Answer 10

Usually by a light sensitive eye ,,they are placed at various points around your town or city,,,