On Monday, 18 December 2017 09:20:14 UTC, Tim Watts wrote:
On 17/12/17 23:06, GB wrote:
On 17/12/2017 22:38, Phil Addison wrote:
My old fluorescent under-kitchen-cabinet tubes are failing at an ever
faster rate, so I'm
thinking of replacing with LEDs, particularly flexible LED tapes.

A few things I'm not sure about...

The light output is quoted in lumens per metre, but how many do I
need? I've seen outputs
from 290 to 780 lm/m for 12V systems and up to 1200 lm/m for 24V. The
tapes will be 45cm
above a dark textured work surface. I suppose you can put 2 tapes
side-by-side for a
higher output.

We tried with just one tape, and the light is very meagre compared to a
fluorescent. You'd need several, not just one or two.

A fluorescent tube is about 3000 - 4000 lumens per meter. So, you can
work out exactly how many tapes you need for equivalent light output.

These are upto around 1300 lm/m:

https://www.led-lighthouse.co.uk/led...waterproof-24v

But bear in mind all of that is going down, rather than up, backwards
and forwards.

I have some (in a different application) and they are *bright*.
Blindingly so if you look at them directly without a diffuser.

Thanks for the links Tim. I think I'll be getting a short piece of middle of the range lm/m to experiment with!