On Monday, 4 March 2019 11:43:43 UTC, wrote:
On Monday, 4 March 2019 11:31:20 UTC, whisky-dave wrote:
On Friday, 1 March 2019 19:35:03 UTC, Dave Plowman (News) wrote:
In article ,
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'd always thought that it was impossible,
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 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.

With the electronic ballasts I have here, all you need to add is a simple
pot to dim them.

Good for yuo all we have is 2 panels with 8 rocker switches on each to control the lights, not sure I could have replaced those 'rockers' with 16 pots just like that.

If they're the old type that flash during starting, just loosen the starter on a fitting & it doesn't start. Easiest way to dim the room.

So I go around with a ladder messing about with upto 20 tube starters not thanks.


Why dim? IME nearly all commercial & school fluorescent installs are heavily overpowered.

When the projection system is being used or they want to show slides or whatever I assume. I don't think we asked for dimmable lights. well it wasn't part of the things I wanted in the lab.






NT