On Friday, 1 March 2019 16:02:52 UTC, NY wrote:
"whisky-dave" wrote in message
...

Dimmable fluorescent fittings have been around since the early 1960s.
Nothing new there.

How are fluorescents dimmed?

I waqsnt; sure so looked it up.

https://www.etcconnect.com/Support/A...ures-Work.aspx

I'd always thought that it was impossible,

well I knew it was possible but a bit more difficult than just replacing a light switch with a dimmer switch.


and
was surprised when the fluorescents in my school lecture theatre could be
dimmed. They were probably installed in the early to mid 70s, which gives an
idea of what technology was available then.

I had a brief look at how the stage lighting in the school worked in the late 70s, just seemed to be large covered rheostats covered in dust.
A selection of coloured filters were in a cardboard box too.


I remember a huge cabinet about
the size of a 6-foot high freezer in the projection unit which gave off a
hell of a hum as the lights were going from full off to full on, which they
did on a timer: the lecturer pressed a button and they dimmed/brightened
automatically over the course of about 5 seconds.

Yes most of us have evolved since those days, in most cases we have better kit and better ways of doing things now.