Why street lights on all night?

Jan 07, 2009 86 Replies

It's 120 times a second (there's a zero-crossing after EACH half-cycle), and power doesn't stay off very long. Probably not long enough for the filament to cool and cause thermal stress.

How would you feel about driving into a completely dark street?

When it gets dark early, I do it every day. My car has headlights so I can see. Yours probably has them too. Look for a switch.

we did that a lot about a year ago. it would take the city or state months to replace miles of copper pulled out of the conduit between the lights. the dark bridges across the river were the only places folks seemed to care about.

crime- down here, storm windows are a good crime deterrent since few houses have them.

-- larry/dallas

Right! In fact, there are no common electric light sources that use any significant amount of energy when starting compared to their average operating energy and that includes incandescent, halogen incandescent, fluorescent, metal halide, high pressure sodium and LEDs. Any initial energy pulse is far too brief to make any difference on anyone's electric bill.

Incandescent lamps are, of course, subjected to on/off cycles because of alternating current; but incandescent flashing sign lamps get a double dose -- from the power line and from the flashing device as well. But, lamp manufacturers rate sign lamps for the same life whether they are steady burning or flashing (3000 hours is a typical life rating).

TKM

Your right. I am glad I was not taking a test. :-)

Interesting comment. I believe that France and Italy are experiencing static populations and Europe as a whole has significantly lower population growth than in the past. Japan, I believe is also experiencing an ageing population. All of which are countries "that had their day" and therefore in "relative decline". I do appreciate your comments, though the demise of China, Egypt, Rome and Greece historically does not require more recent dynasties to collapse either to a major extent or at all.

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