Adrian Godwin wrote:

Andrew Gabriel wrote:

Have you checked the ballast rating? I bought some electronic
ballasts for a kitchen lighting project a while back. Some of
them were rated something like 95-277V input.

If you are underrunning the tube and the ballast wasn't
designed to do this, you will shorten the tube life.
It's difficult to predict how a ballast will behave when
operating outside its design rating.

It's a Philex spiral "Eco" CF lamp with an integrated ballast, rated
at 18W, 220-240V. I don't much care if the tube life is reduced, but
I'm not sure what the ballast consists of and if it's running twice
the current to provide 18W at 110V I guess something might get hot.

The only practical solution I can think of is to break one open, discover the
components used and 'reverse engineer' it. The main difference is that the 'HT'
is going to be running at half the intended voltage. Better than the other way
round at least !

Graham