Don Klipstein wrote:

Eeyore wrote:
GregS wrote:
Eeyore wrote:
Arfa Daily wrote:

With a bit of work, I'm sure that they [LEDs] will
also get to the point where they can replace a standard filament bulb, in
the same sized package, unlike a CFL which has to accommodate the ballast.

To run LEDs efficiently from 240V AC will also require some active electronics.
I see no-one ever factors in the power losses that'll be associated with that.

When you use up the watts, you get heat. The lamp has to efficiently get
rid of it. May even need a fan.

Quite possibly so. How many watts does the fan need ?


In my experimental 45 watt, 9- 5 watt Luxeon array, I use copper, aluminum, and a fan.
DC drive is nice.

The normal home doesn't have DC. What do you use for current limiting
and how much power does that dissipate ?

Electronic ballasts for fluorescent lamps (including the ones in all
spiral and most other screw base CFLs) require DC, so require conversion
of AC to DC, and for that matter back to AC of a higher frequency. Many
of those don't have huge losses, in fact usually less loss than iron core
inductive ballasts.

I was asking about LED drivers not CFLs.

CFLs already include those losses in their stated power. LED fans only ever quote the DC
input power required for the 'chip'.

Talk about an uneven playing field !

Graham