On Wed, 24 Apr 2013 11:06:50 +0100, Ian Jackson wrote:

In message

g, Steve Firth writes
Dave Plowman wrote:
In article ,
Major Scott wrote:
But in any case it is irrelevant. It's the current they are driven with
that matters - not the voltage.

If this pulsing can make them appear brighter than they are, why don't
they use it in domestic LED bulbs?

No idea. They are crap and I wouldn't have one in the house.

The LED bulbs I have used have been anything but "crap". They use 1/10th
the electricity of equivalent halogen bulbs and can be bought as flood or
spotlight versions.

I was under the impression that they did use a pulsed supply in domestic
lighting.

If they do then it's a much higher frequency. Some old cheap ones I've got have a definite flicker, but that's mains flicker (I looked inside one I accidentally dropped from the loft through the hatch onto wood flooring and smashed it and found simply a bridge rectifier, a capacitor, and a couple of resistors, with 50 tiny LEDs in series).

The decent CREE ones I've got have zero flicker. Here's one that expired and I opened to show Ian Field the circuit a month or three ago if you want to try to work out what it does:
http://petersphotos.com/temp/cree%20circuit.jpg I don't have it anymore it's gone in the bin.

--
Interesting fact number 476:
80% of millionaires drive used cars.