Brings back memories of dismantling these. Must be getting rare now. I always wanted to re-use the ballast but never came up with a good use. The paint seemed to become chalky and would come off on your hands.

In the nineties I dismounted too a lot of these. I reused with success some of the ballasts for small tubes like the T5 8W and 13W and for one PL-C of 18W. Yes the paint often was coming off but this was not a real problem for reusing it.

Why did you tear it apart

The tube was EOL

May you, please, show some details, how the glass bowl hold on the plastic?

These snap on. I managed to get mine apart without cracking the plastic but it wasn't easy! Maybe warming it with a heat gun to soften it will help.

I was planning to put an alternative lamp in mine but unfortunately a relative (clumsy by nature) managed to knock it off the shelf above the stairs and it smashed the diffuser as well as the tube, which was heavily used but still working.

I still have the ballast and base, I have thought about using it for other lamps but don't know the specs for this ballast. I believe it was an SL-25 (Prismatic version), will have to dig it out and have a look.


BG

The SL25 would correspond to F21T5, at least very alike, so about 0.22A into ~100V arc...

For the latches: What I'm looking for is some more detailed photo of them, to recognize how big, how many and where exactly they are. With this information I believe the disassembling will more likely to end up successfully (so possible to put back and then hold together... )

Much easier to take off the diffusor on SL* lamps with black bases as they are different to the newer ones.

I just checked and unfortunately I appear to have disposed of the cap and base otherwise I could have photographed mine; however the stamp on the ballast is 25101 LA1 D9 26C (assuming by this I was right in my recollection that this is indeed a SL-25 ballast). That is great knowing it will run 21W T5s as I have been planning on making a batten for one of these (and an 80W version). The 21W can be a low profile fitting as the ballast is nice and compact .. but wider than a Fitzy mini lightpack.


BG

Just check the current, I may be wrong, it was only a guess based just on an assumption Philips designed the system for minimum ballast losses, so used there as high voltage tubes as possible with glow starter and series choke. And the maximum voltage such ballast could handle on 220V is about 100V on the arc. Given estimated ~5W ballast losses, it yield ~20W on the tube. With power factor 0.9 on the tube given the sine current vs rectangle voltage it would mean current of ~0.22A...
But it could be anywhere between ~0.2..0.27A (expect the arc voltage won't be outside the 80..110V range)

I will do some tests to find out

BG

@Medved:
I've to check in my basement if it's still here(but I doubt).
But I remember that it's very tricky to open it without damage the glass because the plastic is very very tight.

The older black base version is very easy to open because the plastic base is made from two separate parts.