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LED lighting

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I think that's probably a good summary - only a proper examination of the subject will confirm it.

On that basis: lumens output per electrical watt input provides a measure of the efficiency* of a lamp, but I think lux is probably a better measure of its usefulness.

* The sources seem to prefer the term "efficacy", but I don't understand the distinction.
 
Mikes link above said:
As a frame of reference, a standard 120V/60W light bulb is rated at 850 lm, and the equivalent 230V/60W light bulb is rated at 700 lm.
Why would the voltage make a difference when the wattage is the same?
 
Why would the voltage make a difference when the wattage is the same?
Presumably lower voltage bulbs are more efficient at producing visible light. I don't know why but as they will have thicker filaments I'd guess that may have some effect on the function.
 
Ironic.

Pretty early in this thread I was bemoaning the non-uniform output of LED lamps compared with the GLS I wanted to replace. Unless it's a single-lamp fitting, the light distribution can be largely compensated by using a fitting which angles the lamps in complementary directions, but of course I'm too tight to consider entire new light fittings.

(BTW: I regularly pass a lighting showroom with all manner of weird modern lighting I wouldn't give house room nor have the space for, because of the artistic opportunities offered by distributing individual LED chips over a surface rather than as a replaceable module, but new regulations for repairability are going to shake all that up!)

The irony is that I have a couple of reflector bulbs where I want directed light with little overspill, one has failed, and now incandescent spots (or any other incandescent lamp) is unobtanium off the shelf. I bought a pair of cheap R50 SES form-factor LED lamps to plug the gap, but although they fit the fitting these do not perform the desired function of providing directed light.

In fact, I didn't even used to have standard R50s in those fittings, my preference was the narrower beam version with the bevelled edge, so the 180º spread of these LEDs is a bit of a shock.

af123 was extolling the virtue of reflector LEDs:
I've just replaced four halogen R63 spots in my kitchen with these and they're superb. Can't tell the difference at all apart from a brief delay in turning off once the switch is thrown.

http://www.homewatt.co.uk/led-and-l...lector-bulb-e27-warm-white-5060283472616.html
...but that website no longer seems to be working. Any ideas?
 
That site lists six R50 options, three of which are 110º+ and three 36º beam angle. Interesting.

(The site itself is slow and unresponsive on my bandwidth!)
 
@BH My bandwidth is good but I had similar issues and blamed my VPN. At least it gave you some food for thought.
 
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