In message , "Dave Plowman (News)"
writes
In article ,
David wrote:
I am trying to fault find a fluorescent light on the 12V circuit in our
motor home.

Opinion seems mixed, but there are several postings which claim that
these are actually 240v AC lights with a built in inverter so that they
can run off 12V.

There is certainly a lot of circuitry inside.

Firstly, do camper/caravan/boat 12V fluorescents usually run at 240V
with a built in inverter (or sometimes)?

Secondly if so is there usually clear marking of the 12V and 240V parts?

I don't particularly want to probe a 240V AC circuit with the 50V DC
part of my little multi-meter.

There are probably lots of ways of doing it but the most simple is
basically just an oscillator and transformer to produced approx 240v AC.
Plus a way of producing a higher voltage pulse for starting.

A thought about replacement, with a bit of mechanical ingenuity, an
emergency light unit would provide the parts to make a good replacement.
Probably a darn site cheaper than a new fitting from a motor home shop.


--
Bill