My early groove shaded LEDs were set in aluminium U tubes arranged horizontally, but it was a lot of drilling.
The scoreboard I have nearly finished today has 1000 LEDs, and its only a medium sized one.
I suppose the next step is to build a single LED row per segment with the new super- ultra- brite LEDs and see if that will now work in the sun with no shading. I do have some spare pcb strips from indoor projects.
I have heat problems if I fit the electronics inside the actual scoreboard, the temperature can get very high, even with some ventilation.
The surroundings of the displays are usually black, so you have this massive solar collector. Some customers insist on a black facia which drives me mad.
The radio receiver and the micro controller board I mount on the back of the scoreboard in a ventilated white box, hopefully in the shade.
The TPIC6B595 driver chips behind each digit are rated to 125 deg C, and strangely enough, I havn't had problems with the LEDS - I have had a handful of LED failures in the last 40,000? LEDs over the last 5 years. The front of the LED has been in fresh air which must take some heat away.
I don't know about Africa but here the sun is not so bright when it's low in the sky.
Its bright in summer till it hits the horizon , look at some safari photos That's why trying to shade the LEDs was such a pain.
I Think a hand full of them, then having the light diffuse would be enough to do it... (just 1 of those gives around the equivalent 80watts worth of incandescent light, I'm using one now!)
I wonder if something could be done using polarized filters?
Thats what I was thinking if I could make a backlight from a light pipe shining sunlight through LCD, but polarized filters could bear some thinking about.
I was worried LCD might overheat blocking the light, but they use something like it on welding masks . hmmm...
My friend just patented solar batteries for cell phones and now he's going on to expand his range.. so at least that could get batteries to last longer!
With the heat you get, maybe a Stirling engine and generator.
Put these into the youtube search box:
GIANT DEATH RAY Daniel's DIY $25 giant parabolic
Parabolic Mirror from a Trash Can Lid
Solar Power Parabolic Trough Mirror Kit Evacuated Solar Tube
Fresnel Lens and a Stirling Engine for FREE ENERGY Solar
SOLAR PANEL DIY MAKE YOUR OWN SOLAR
less than $1 a watt DIY MAKE YOUR OWN SOLAR PANEL
When I see the ones with Denise, I don't seem to be able to remember what was said.
Theoretically would it be possible for a battery the size of a AA to have a capacity of say 12 volts at 20 amps an hour?
Maybe. At some point there are limits to the amount of energy you can get from a chemical reaction. But gasoline, for example, has about 30 times the energy density (per volume) of Li-ion batteries, and methanol about 15x (but you'd need air as well.) So the fuel-cell technologies have some potential. For example, chemical rocket fuels have a maximum possible power, which has pretty much been reached (at least on a per-mass-of-fuel basis. there's lots of fun to be had optimizing "other" factors.)
The chemical energy limits are a bit beyond my current abilities to calculate
There are probably more practical limits. Even current battery technology is relatively dangerous, capable of nearly bomb-like behavior under the wrong circumstances.
Theoretically would it be possible for a battery the size of a AA to have a capacity of say 12 volts at 20 amps an hour?
You could use it for car battery then, but the starter cables are normally a larger diameter than an AA cell ! Then we start thinking superconductivity to make the leads smaller
Then there's the terminals ! you can't have 2 little coil spring contacts...
That's why trying to shade the LEDs was such a pain.