Do CPO-TW lamps lie to us?

[AgentHalogen_87]

Beta 5 - They're all Philips Dynavision 'brick' style ones dating from 2012 give or take. The only difference between them is what the text says they run.

Kev - I am indeed. I could get hold of some 140s. I just need to be careful what (and how much) I take directly from the stores. We only have a few boxes of CPO lamps left of any power, and we can't get any more. I'll see what I can do.

[AgentHalogen_87]

This mystery has now been solved. The 45W ballasts drive the lamps at 60W for the first 20 minutes or so before settling down to the correct power draw. Early CPO lamps had no difference between them, 45 and 60 lamps could run on either ballast no problem, but apparently more modern ones are different. You can run a 60W lamp on 45W gear but not the other way around.

[Beta 5]

Interesting to know, I guess that is to accelerate the warm up and stabilisation of the lamp? I wonder is there a noticeable drop in brightness when the ballast drops down to 45W after the 20 minutes?