On 28/04/2021 11:49, Tim+ wrote:
John Rumm wrote:
On 28/04/2021 08:18, Tim+ wrote:
John Rumm wrote:
On 28/04/2021 07:35, Tim+ wrote:
Dave Plowman (News) wrote:
Think it's generally known that dimming a tungsten bulb reduced its
efficiency dramatically. In other words, a 100w dimmed to half brightness
used a lot more electricity than a 50w on full. Although dimming did
extend the life of the bulb.

So how about LEDs? Since they generate far less heat are they still as
efficient when dimmed? And does dimming make a difference to their life?


Until they can make the colour temperature of LEDs drop as they dim, Ive
decided Im going to just avoid using dimmers with LEDs as the just look
ghastly as the dim IMO.

Some do IME. I used some of these:

https://cpc.farnell.com/philips-ligh...b38/dp/LP10204

I found that they dim in a very "tungsten" way - i.e. the colour temp
falls smoothly as they dim, and the dimming range is very wide - going
down to close to "barely glowing".



Thanks. Whats the key search term to make sure I get the right ones? I
could do with some candle bulbs with standard bayonet fittings.

Not sure if there is a key search term, I just know that that particular
one I linked to behaves in that way. There is a reasonable chance that
other lamps in the same range may behave like that.



Thanks again. I found the bayonet version that I wanted and was about to
order 5 for a ceiling light in our sitting room but then remembered that we
only ever turn the light on when we first enter the room. After that we
use a desk & standard lamp (both LED) with another standard lamp if we
need more light.

I reckoned in terms of ROI Id probably have to live to 150 to make
swapping all the bulbs worthwhile. ;-)

Well you could buy one, swap it one when a bulb goes, then rinse and
repeat. Hopefully there comes a time where you don't need to swap them
again for a very long time. So you get a convenience payback as well as
energy reduction :-)

Still, nice to know such bulbs exist and who makes them for future
reference as Ive got some G9 fittings that need replacing in our dining
room and I would like a dimmable overhead light here.

I have found the only real way to find decent lamps where there is a
very specific use case, is to just buy the odd one on spec now and then
and see how it performs.

That Philips one I go particularly because I wanted a dimmable that
could project a bit of light upwards when installed in a cap down
fitting - to get a bit more diffuse bounce back off the white ceiling.
So the dimming range and colour temp shift came as a pleasant surprise.
I replaced the other 7 to match in the end.


--
Cheers,

John.

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