Help! Why does my homemade light work?

Hi everyone, I'm new to using LED's in general. What I did is purchased 6 of the following UV LED's:

http://www.superbrightleds.com/leds/uv_specs.htm

I then took a Mag Lite that uses 6 D cell batteries, took an extra bulb, broke it, and soldered the 6 LED's in a pattern like this on the end of the bulb: (view from looking into face of flashlight)

[image]http://cleedo.com/leds.bmp[/image]

Then I put it all together. It shines really bright UV light and I tried using it for scorpion hunting. It works great so far and I can see scorpions glowing green from like 15 feet away.

Now, my question is, shouldn't this burn the LED's out? I'm running them at 4.5 volts when their max is supposed to be 4 volts. I have no idea what Ma the batteries are because the damn things don't say anywhere on them. They are fresh batteries. So far I have used the light for approximately 4 hours straight without any noticeable change in brightness or color.

Why does this work? Is it just going the make the LED's not last very long? I took the lens off while the light was still on and had been in use for 30 minutes or so and the LED's were not warm.

Please tell me what you think. Sorry about my ignorance in this area, I'm just curious about this particular project.

Are you using a spacer and 3 D cells in the light? Or are you using a resistor and 6 D cells?

It would appear from your post that you are actually supplying 9volts from those 6 D cell batteries. To supply 4.5 that you say you are supplying, you would need to use only 3 D cells. You didn't say whether or not you wired them in parallel or series...but you did say they were bright...So I'll assume parallel. From your post it also appears that you didn't use a dropping resistor. I can assure you they will not last very long at all with that setup.

FYI: You should either have this post or the other one locked. Cross-posting is not allowed and can get you banned. Contact an admin. or mod.

I burnt out some UV's myself not too long ago...trying to overdrive them. /ubbthreads/images/graemlins/wink.gif I've found that I really don't need to overdrive them. I just use a larger array now. If using the six D cells... try adding a 180 Ohm resistor to each led... You'll get a longer runtime anyway.

Ok, I'll lock this thread...please go to this one to continue. /ubbthreads/images/graemlins/grin.gif