http://www.caves.org.uk/led/le d-myths.html Interesting detailed discussion of LEDs as lamps; designed for caving, but useful engineering information for this project as well. Includes a schematic of a current regulator. "you want to get a good price, you must order at least 50, directly from a distributor." - well that's OK, I want a few hundred.... umm, but: "if you want the equivalent of a 70W lamp you will need to use a thousand LEDs." - ok, maybe I'd better stick to halogens.
http://www.ccrane.com/1 20_volt_white_led_bulb.asp offers a 20-LED module that screws in to an ordinary bulb socket; $70. This could get pricey! maybe LEDs are not the way to go.
http://www.tr ainweb.org/girr/tips/tips7/white_led_tips.htmlhttp://www.trainweb.org/girr/tips/ tips7/white_led_tips.html tips about white LEDs relating to model trains
here are some package replacements for standard light bulbs - LED assemblies for railroads, trucks, etc.: http://www.ledtronics.com/ ds/RR003/default.asp http://www.l edtronics.com/ds/Loading_Dock_Signal/default.asp This is definitely impractical. Stick to halogens.
hmmm, how about renting a searchlight? http://www.skyblasters.com/sb180.ht ml, http://www.skyblasters.com/sb180.ht ml lets' see, 115 volts * 10 amps = 1100 watts that's.... fifteen bikes. No, I don't think we can do that, even though it'd be a terrific show.
Home Depot carries a lot of DC halogen lights for kitchen applications, and they aren't too expensive. Unfortunately, their web site sucks and won't let you link to individual product pages. Individual 20W halogen bulbs are about $7, though, and they sell a floodlight kit based on that bulb for $14. A 50 watt version of the same floodlight is $20... maybe a better deal. They also have some high wattage lights designed for 120VAC - $25-$30 for a big ol' floodlight. I should find out how such a light would respond to lower voltage DC current.
Apparently "MR11" is the specification to look for; here is some information about 12V halogen lamps. These folks are selling them for about three-fifty per bulb in packages of ten, which seems pretty reasonable. We could run four or five bulbs per module.
Table measuring the efficiency of various lighting technologies in lumens per watt. Looks like halogen and LED are comparable, but fluorescent beats 'em both silly. Hmm... they're expensive, though, and what's this about a "cold-weather ballast"?
Ahh, so part of the reason LEDs make sense in flashlights is that they throw all their light forward: they are very focused. Also, small incandescents are very inefficient, so LEDs come out well by comparison.
Don K.'s LaserPage - useful and practical tips about cheap laser hacking. Sounds like prepackaged units are better than trying to build lasers from raw components. Includes a link to some cheap suppliers.
Discussion about the use of laser pointers to disable street lights, with various interesting pieces of safety and power information.
Discussion about adapting a laser pointer to external power, with information about voltage and current requirements.
Information about laser hacking, explanation of green lasers, some talk about different models of cheap laser pointers and what to look for.