Andy Burns wrote:
Paul wrote:

Brite Source LED Corn Light [claims 135 lumens per watt, unlikely]

Apparently you *can* buy 200 lumen/watt lamps,
but only if you live in Dubai ...

https://youtu.be/klaJqofCsu4

Page 2, efficacy plot (green line).

Yes, low current gives enhanced output, but notice that
it's only at the bottom of the operating area. You need
a lot of LEDs to do it that way.

One bulb contains a lot of LEDs.

You need multiple bulbs for a lighting job.

$$$ = Perfect for Dubai.

The only way such a thing would gain traction here, is
if there was a government mandate for a certain level
of bulb efficiency.

If you look at what Dubai uses for police cars,
you get some idea of how they think there.

I suspect one of the assumptions in the circuit design
there, is that the voltage on mains "stays within specs".
This would not help me, because my voltage is pretty
well always out of spec. Right now, I checked my
Kill-O-Watt meter and the voltage is right on the edge
of the max allowed. This would not be the ideal operating
point for a capacitive dropper design. The nice thing
about SMPS powered bulbs, is they can have a much wider
voltage range.

Paul