Q) I tried to charge my new light under a lamp and it does not work. What
should I do?
A) Our lights will not charge indoors under a lamp with artificial lighting.
They need to be placed outside in direct sunlight to charge. Before
packaging lights the batteries are tested and 30% charged. We recommend
placing allowing up to full 3 days of sunlight to fully charge the batteries
before initially using the light.
How does that work then? I thought light was light?
--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
An unrelated and useful bi product of this type of differing frequency
sensitivities in electronic devices is the ability of most digital
cameras being able to respond to the Infra red frequencies from remote
controls.
If you suspect your tv remote is not working, just view it through your
digital camera which effectively converts IR into visible light.
Ain't science wonderful!
Bob
Sunlight is rather brighter than most artificial - a camera will confirm
this for you :-)
Shine even a 500w flood on a wall in broad daylight and you would have
some difficulty in telling if the lamp was on or not - all due to how
dim lamps are when compared to sunlight. Hence the photocells need the
sunlight hitting them to produce any useful output.
--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk
--
John Stumbles
Bob the builder / it'll cost 'yer
Bob the builder / loadsa dosh
You were mistaken.
Sunlight is really, really, *very* bright. 1.3KWH per square metre or there
abouts. Creates more global warming than, well, anything else really ;-)
Artificial lights produce an, erm, 'artificial' light. Very low colour
temperature, zero energy up towards (and beyond) the violet end of the
spectrum.
You can buy pro light meters (I have one cos I worked on interior lighting
systems many eons ago), or buy a ten quid market-stall solar battery
charger and measure the voltage/current.
Sunlight is very, very strong :)
Al.
"John Stumbles" <john.s...@ntlworld.com> wrote in message
news:763frtF...@mid.individual.net...
> Incidentally I stuck some full capacity NiMH cells into some cheap solar
> lights I bought, replacing the part-capacity ones that were so lightweight
> they must have been practically empty, and they run practically forever
> once they're charged up.
However they won't charge in a single day so they last about the same time
each night as the cheap ones fitted.
Oh goody. I had some of those 'rock lights' with 600mAh AA's in & replaced
the dead cells with 1300mAh. So as long as they get a good charge, I'm
ahead of the game.
SWMBO came home today with a solar LED light from DSL, purchased from
Morrisons.
The destructions say; "You can also charge the solar lights outdoors then
use them as indoor illumination"
So that confirms that sunlight is stronger or of different wavelength than
internal lights.
Well I'll go to the foot of our stairs.
I was helping to run the local May Day carnival in town today, a heavily
overcast cold day, when I bumped into a friend who said "The UV is strong
today".
Being an Old Fart with little up top, I thought he was referring to the sun,
that I had not seen, affecting my complexion. Nope, my photochromic lens
were black.
Ooops, sorry I was distracted when I originally sent this!
>>> Being an Old Fart with little up top, I thought he was referring to
>>> the sun, that I had not seen, affecting my complexion. Nope, my
>>> photochromic lens were black.
>
>Ooops, sorry I was distracted when I originally sent this!
Lenses too dark?
> So that confirms that sunlight is stronger or of different wavelength
> than internal lights.
Both.
It's far stronger - I have a nominal 250W 'daylight spectrum' bulb and
the sun through the window still casts shadows when it's on.
The sun is also much wider spectrum than any bulb - around 300-2500nm
wavelength at ground level. We can only see 400-700nm(ish). Even top
quality 'daylight spectrum' bulbs don't bother trying to match the
further reaches of Ultraviolet or Infrared - and we can be glad they
don't...
Yerbut, nobut, yerbut. At the front of handyman towers I have a dawn dusk
lantern (no PIR) with an 11w thingy bulb (sorry, lamp) and about 8' away on
the front of the garage I have a 500w halogen light (manually switched, no
PIR).
If I'm loading the van at night & switch on the 500w jobby, the dawn dusk
goes out, until the 500w is switched off again. So (a) how come the 11w
lantern doesn't switch itself off evey time it switches on and (b) its seems
to react to a 500w halogen just like sunlight.
My brain hurts...
>
> Yerbut, nobut, yerbut. At the front of handyman towers I have a dawn dusk
> lantern (no PIR) with an 11w thingy bulb (sorry, lamp) and about 8' away on
> the front of the garage I have a 500w halogen light (manually switched, no
> PIR).
>
> If I'm loading the van at night & switch on the 500w jobby, the dawn dusk
> goes out, until the 500w is switched off again. So (a) how come the 11w
> lantern doesn't switch itself off evey time it switches on and (b) its seems
> to react to a 500w halogen just like sunlight.
>
> My brain hurts...
>
>
The sensor in the dusk-dawn lantern is located so it is in the shadow of
the lamp, so the lamp does not trigger the sensor.
Clearly, when you switch the 500W halogen on, the beam from the halogen
*does* impact on the dusk-dawn sensor.
This indicates that the dusk-dawn sensor is quite sensitive (you may
notice that the lamp doesn't come on until it's pretty dark and goes off
at the first hint of dawn). This is good for environmental reasons!
If there is a sensitivity control for the dusk-dawn sensor then if you
turn the sensitivity down (i.e. towards the sun icon) then the halogen
won't trigger the dusk-dawn sensor and the dusk-dawn lamp won't go out
when the halogen comes on.
> Yerbut, nobut, yerbut. At the front of handyman towers I have a dawn
> dusk lantern (no PIR) with an 11w thingy bulb (sorry, lamp) and about 8'
> away on the front of the garage I have a 500w halogen light (manually
> switched, no PIR).
>
> If I'm loading the van at night & switch on the 500w jobby, the dawn
> dusk goes out, until the 500w is switched off again. So (a) how come
> the 11w lantern doesn't switch itself off evey time it switches on and
> (b) its seems to react to a 500w halogen just like sunlight.
The sensor on the 11w dawn/dusk will be a very primitive (i.e. cheap)
photocell used to trigger a solid state switch. All it measures is
brightness - it doesn't care what it is, unlike solar cells. The normal
(cheap) Cadmium Sulphide photocell is sensitive to the whole visible
range and a bit further, into the infra red.
Your 500W halogen light will be kicking out a LOT of infrared (or, as
many people know it, heat).
The reason it doesn't switch itself off is (usually) simply because the
sensor is let back a bit into the case - light travels in straight lines
so its own light doesn't reach its own sensor.