We have a lamp post in front of our house, that uses a 50-watts HPS (high-pressure sodium) lamp, and opens by itself at night using a photo-cell.
For a while now, it's been acting out: when it opens at night, it brightens gradually for about 50 seconds, then goes out, "sleeps" for about 80 seconds, and that cycle repeats all night.
Here's a video of this in action: https://video.nest.com/clip/a3cf509f134546acad14117a4fcb58dd.mp4
And a 4x time-lapse that shows the change in brightness during that same period: https://video.nest.com/clip/436e5f3e215748268b8d9582ebef8c46.mp4
Last time we had an electrician look at it, he thought it might have been the photo-cell that was acting out, and he replaced it. It was OK for a while (many months) but now it started doing exactly the same thing as before!
What could be the problem?
Can I swap that HPS lamp with something else, maybe a LED lamp..? Not sure what the connector is...