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Posted by Eeyore on May 14, 2009, 6:21 pm

z wrote:

I see you fail to provide a current measurement. Typical of 'greenies', they
haven't a clue what they're talking about. They just like advertising talk.

90 secs / hour is 2.5% of the battery capacity ( simple arithmetic ) . No, I
can't for one second believe that. Let's say the laptop consumes ~ 100W, the
LED light would be only 2.5W.


Posted by z on May 14, 2009, 6:51 pm

I don't have the ability to measure the amperage of this little USB
light.  And i'm not a 'greenie' by choice.  I'd have electricity from the
grid if I could in a heart beat.

It would be a lot less than that.  The input voltage is 19v at 3.42 amps
on this laptop.  When running under batteries w/power saving on it would
be much less than 64 watts total.

the max you can push through USB is 500 mA @ 5 volts which = 2.5 watts

This light has a switch which either turns on 8 LEDs or 4 LEDs, so you
could expect that using the 4 LED setting the max it could be using would
be 1.25 watts.  I could tear it apart and see just how much juice each
one of those LEDs require but I don't think i'll bother. I seriously
doubt its maxing out the USB amperage but anyway here is a real world
test from a review:


"Kensington says the FlyLight uses approximately 90 secs per hour of
battery to run the FlyLight. I decided to give this a test and I charged
my battery full and left my computer alone with the screen saver turned
off, with no FlyLight plugged in. Exactly 3 hrs 36 mins and 29 secs later
the computer went into Sleep mode. I again charged the battery, plugged
in the FlyLight, and left the Laptop alone. Exactly 3 hrs 30 mins and 54
secs later the computer went into Sleep mode. That is only a different of
5 minutes and 30 seconds for a little over 3 1/2 hours of use. Almost
right on with their suggested amount of battery life being used. In my
opinion the light is worth the 5 minutes and 30 seconds of battery life
that I will lose for the added convenience of a portable light. "

So compared to a CFL or most other household lighting its good enough to
sit in the dark and see your keyboard.


Posted by Jim Wilkins on May 14, 2009, 10:13 pm
Look at the properties of the USB hubs in 'Device Manager'.


Posted by Eeyore on May 14, 2009, 11:17 am

Michael B wrote:

Most rooms aren't at night.


Posted by sspence on May 14, 2009, 12:44 pm

Try making sense Graham. I've never needed auxiliary lighting when
using my laptop, day or night. If I did, I'd fire up my 15 watt CF
which is powered by my solar charged batteries. Before you ridicule
someone else, you ought to walk the talk. Refresh my memory, why
exactly are you on this group? I'm here because i actually live off
grid and use the technologies I promote.

Steve Spence

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