"brugnospamsia" wrote in message
. uk...

You can also dim cfls if you open them up,

please illuminate us :-)

You need to change the mark/space ratio of the tube drive. Best bet
for
this is to get one of the higher end ones (e.g. the ones that turn on
slowly
or those with a dusk light incorporated) as these often have a common
micro
inside that can be replaced with your own code.


... or maybe change the timing components in the cruder type of ballasts ?

Unfortunately in the usual IR simple 2 power MOSFET design, it will still
tend to keep mark/space ratio the same.


The 9 watt lamp I just fitted to my pushbike is currently only taking
4
watts on the camping light invertor and I'm trying to understand how
to
tweak it ....

I think what I was getting at is :- do different designs of tube have
different impedance characteristics ?

Yes. In fact thinking about what you are after one of the r.f. energised
tubes may be your best bet.


I will today be ordering a Maplin twin 8 watt camping light in the hope
that
it will drive one 9 watt mini-spiral correctly.

May be too low a frequency for your light to run optimally


failing this I will have to deal with my phobia of winding inductors .

You can buy them already wound. Several good Chinese and Japanese makes.