On Tue, 16 Jan 2018 09:31:25 -0800 (PST), harry wrote:

Came across this, interesting.
https://ledlam.co.uk/how-do-led-filament-work

'Filament' LEDs are, AIUI, COB and are probably the least inefficient LEDs
generally available. Morrisons have (had?) some 6W, 800lm, 'GLS' B22 lamps,
unfortunately ~3000K (I prefer 4000K+) for a fiver each. I have one and it
is good. I've not checked the actual wattage - OK, just for you:
5W is flickering 4 - 5 and is just under %W based on VAxPF
15W, 1500lm is similarly marginally low
60W incandesent shows 60W - surprising as the voltage is ~245.

5 years ago I wouln't go below 80lm/W; 3 years ago I considered only
=100lm/W, with exception for GU10 for desk and bench lights that don't
spend long on.

Ikea changed to all Led, but those are worse than my benchmark 5 years ago!

BTW, I bought from Ledlam some lamps that have COB on ceramic blades. The
blades are in a triangel and very translucent, with the 'back' of each blade
shining throght th gap between the other two, so near enough 360 deg.
The 3W is 320lm and the 5W is 600lm - this was 3 years ago! How progress
goes - not!
--
Peter.
The gods will stay away
whilst religions hold sway