ECN Forum Forums General Topics of the Trade General Discussion Area HID street lights ?'s

So someone asked me this the other day.

Why would an HID street light, (with a bad ballast) only kick on as someone walks near it?

I thought about it, and realized I had noticed it too, but paid little attention to it. (As I remember a few like this in my youth, long before I entered the trade.) I think about it now, and have no real answer for it. Anyone have any therories for this?

Maybe your shadow made the photo cell think it was night:-} Sorry couldn't resist i have not a clue

NJwireman... No no...the motion sensor picked up the person and activated the light... LOLOL.

Maybe the ballast isn't bad and its the bulb. When the bulb starts to die it heats up and after a while it stops, cools down, and then relights. It might just seem like it only happens when the person is walking by. I bet that if they sat there a while they would see it go out and then relight.
Just a thought.

Dare I say it, and the only reason I brought it up, is that.... When I was about 17 or so, for about a year, so freinds and I hung out on a street corner. At the end of the block was a street light that lit ONLY when you walked under it! No photo cell, no motion detector. But we were always in view of it, and knew that it would only light when someone was near it. So it's not a "If a tree falls in the woods...." thing. As if by walking by changed some element of potential allow the light to kick on.

A few thought provoking points...

When I tree falls in a forest and no one is around to see it, did it fall?... so, does this still happen regardless if anyone is around or not?

The body puts out 100 watts on average, could that effect the photo cell?

What sort of E & M does the body put out? heh

OK, i have too much time on my hands at the moment.