Half-power CFLs

[JohnD]

Down the residential roads, my council has fitted new street lights which have a very "pure" cold white colour, are described as energy-saving, have very little stray light, and go to half-power at midnight. I mentioned it to a foreign friend, who had a look at them, and said they couldn't be LEDs because they didn't have the "dots" of light.

Looking again, they seem to have two tubes like a CFL, about 250mm long, but how can they be turned to half-power? They all change at exactly the same time.

 

[JBR]

By one tube being on a timer?

 

[JohnD]

The two tubes are joined at the end like a G23

 

[333rocky333]

possibly using a dimmable ballast and at certain times somethings connected across the 0-12v terminals.
Tesco do a similar thing using 250watt metal halides and during night the wires from the ballast tappings link different and give off less light.
Google Trim and Dim streetlights

 

[AndyPRK]

I have a cfl in my house. A quick flick of the switch and it goes into dim mode (once warm)

 

[333rocky333]

Id be tempted to put a high vis coat on and have a peak in the base, subject to what key it is, proberly no one will take any notice

 

[Lectrician]

Commercial LED fittings don't have that crap "dotting" effect. Not saying these are LED. Commercial, decent branded LED fittings, do not resemble that budget "matrix" type effect.