Thursday, August 13, 2009
(Edit: Since this was originally posted some time ago and the LEDs I used are long gone, I thought I'd point everyone to Lighthouse LEDs as a source for LEDs. I've never used their stuff, but I've heard from quite a few people who have & they come highly recommended.)
(Edit again: Thanks to Aaron Bolton for pointing out that the fittings used here are actually cpvc. My local Lowes no longer carries the parts, but they are available on their website. The Home Depot stores near me do still carry them, & they're available on the Home Depot website as well.)
A few months back, Otaku over at Hauntforum.com posted a link to some ultra bright blue LEDs at Electronic Goldmine. On a whim I ordered a few of them, not really knowing what I'd do with them. Well the other day I was perusing the isles at Home Depot & happened down the PVC isle. I noticed a few small fittings & it struck me - spot lights! (Cue dramatic music)
So without further ado, I present my cheap, small, easy low voltage spotlights.
(Please excuse the out of focus pictures - the wife won't let me take the good camera into the barn so all I had was my phone)
I started with a section of 1/2 inch PVC, 45 degree 3/4 to 1/2 inch reducers, 1/2 inch PVC caps, 470 ohm 1/2 watt resistors, the LEDs, and some 18 gauge wire.
I drilled 2 small holes in the PVC cap & fed the leads through so that the LED was inside the cap with the leads sticking out. I then hot glued the LED in place.
I then soldered a 470 ohm resistor to the longer lead (anode, positive) of the LED. I plan to run these from a common 12 volt power supply, so I'm not using a battery box. You could use 4 AA or D cell batteries if you replace the resistor with a 120 ohm resistor, or a 9 volt battery with a 270 ohm resistor. NOTE: I used a 470 ohm resistor because I plan to power these with 12 volts, and with the specs of this particular LED it turns out that's the value I need. If you're going to use different voltages or different LEDs, you'll need to calculate the resistance for your particular setup. You can find a great LED calculator here.
Then I soldered a red wire to the resistor, and a black wire to the other lead of the LED (cathode, negative.) I insulated the bare leads with heat shrink tubing, but electrical tape would work as well. Just make sure the bare leads don't touch each other.
I then fed the wires through the 45 degree fitting and nested the pipe cap into the big end of the 45.
Next, I cut a piece of the PVC pipe about 8 inches long, but made the cut at a shallow angle so the end would have a point. I then drilled a hole a couple of inches from the straight end of the pipe, and fed the wires through the straight end and out the hole. After that it was just a matter of pressing the pipe into the fitting.
There you have it. A quick shot of black paint & you have small, nondescript, bright spotlights perfect for lighting tombstones or props. Just stick em in the ground and go.
Oh, and did I mention they're bright?
Here's one of them illuminating the gardening tools (the scariest things in my barn) from about 6 feet away.
There ya have it, hope ya like it.
Posted by Jason at 11:16 PM