Originally Posted by
igarocom
The daytime running lights wouldn't be enough, unlikely would the main light on a faster descent.
Is the DC going through what looks like a PTC at the top edge? A zener somewhere else keeps the voltage down and the PTC heats up as it starts doing so which saves the zener from destruction. Efficiency is poor during normal use but for the relatively low light output and price point it would be acceptable.
No idea about a PTC. Honestly, the only "large" power package on the board is the TVS near the bridge rectifier.
Here's a version of the photo where I labeled the parts that I'd identified so far (which isn't much)...
I added these labels before learning that the protection diode was a TVS.
For what's it's worth, here is a shot of the diode when I was trying to get it to conduct (which I didn't, because I don't have a power supply that goes high enough).
as best as I could tell, the markings are:
1st line: ST @G (not sure about the @ symbol)
2nd line: NY
3rd line: Z537
a buddy was able to look up the markings and concluded that it is a ST SM6T100CA.
This is a 100V bidirectional transorb in a SMB package.
Steve in Peoria