White LED: 25 lumens/watt


per watt of LIGHT output

Incadescent bulb: 17 lumens/watt


Per watt of ELECTRICITY input.

They use different rating systems, or so I read. For instance LEDs would be
damn near 1 watt light out for 1 watt electrical in. Lumen is color-balanced
perceived intensity, highest near 500 nm depending on brightness.

Battery-powered ballasts to fluorescents will not be as good as the
numbers quoted, but they can come close.

I use a Shack inverter with low idle and reasonable efficiency to power two
each 9W spirals in desk lamps on the handlbars of the Ultracapcitor Bike. They
can be interchanged to a whole series of colors and strengths quickly. The
whole thing is pretty efficient. I just need to wire the lamps to the outlet
box to the inverter to the motor. A few minutes with the crimper.

A brilliant 100W incandescent equivalent at less than my old 35 W tractor
headlight, the one that took my up the trail at night, powered by pedaling.

Anyway, different system, non-interconvertible results. Read Grainger they have
good article on what's it called, fixture efficiency? Plug-to-light including
for parking lots, light lost to the wrong (telescope frustrating) directions.



Yours,

Doug Goncz (at aol dot com)
Replikon Research, Seven Corners, VA

1100 original posts at:
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