Date:         Sun, 28 Jul 1996 10:35:38 CST6CDT
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         "Dan Houg" <fairwind@northernnet.com>
Subject:      Re: basic electronics question


to All:

thanks for ALL the responses!!  funny how a cut-and-dried law of 
physics can have so many answers... just like life.

the jumbo orange, 12000 mcp LED is really neat.  it produces an 
intense beam of light that is extremely focused.  it will shine a 
bright orange spot about 8" in diameter on the wall @ 20'.  it is 
perfectly bright enough for reading, which was my goal, tho the color 
rendition may take some getting used to.  at least my night vision 
shouldn't be affected!  they also sell a jumbo yellow 50ma but it is 
rated at 1/2 the light output, tho the color would be more suitable 
for reading.

using a cheapo 12v power supply, that puts out about 15v unloaded the 
LED drew about 80ma with a 280 ohm resistor.  1/2 watt.  the resistor 
did not heat up.  the LED is rated at 50ma continuous, 100ma surge.  

the idea of resistance heat going to waste bothers me :)  so, i think 
i will get a few more LEDs, cluster them in series for about 12v, and 
have an extreme amount of light for 50ma @12v.

all great ideas, thanks to all who responded.
-dan