I went ahead and ordered some more LEDs off ebay. This little LED flashlight is made from an empty Italian spices container, and took me about an hour to put together:
It’s powered by a single 9v battery, so the two pairs of parallel-wired LEDs are getting about 4.5v each (I knew through previous experimentation that these LEDs can take about 7v before they blow becoming SEDs or Smoke Emitting Diodes).
It makes about as much light as an ordinary flashlight, and about as directed too.
The other project I put together recently (all while I had more pressing things I should have been doing) is a table/desk lamp that used half-watt LEDs of a design I have never used before.
These LEDs are so high-powered that they come embedded in their own steel heat sink.
The problem came trying to figure out how to mount them. They have notches in the side so you can bolt them to something metallic, thereby further dissipating the operational heat gain, but the solder points for the cathode and anode terminals are on the same side as the light element, which is the reverse of normal LEDs. So I couldn’t have the light element hanging out of the mounting material, leaving all the exposed electrical points safely inside the device, which had previously been my design strategy.
The solution I devised, was to mount three of the LEDs in series (to a 12v source, which maxes out the recommended 4v operating voltage). They’re bolted to a metal strip (spray-painted black for aesthetic reasons) with a transparent plastic strip bolted ontop to limit the amount of casual electrocution (although at 12v and presumably 1.5watts, we’re not talking lethal quantities of juice here).
The finished lamp puts out about as much light as all 80 LEDs of the previous chandelier project. The image below was taken without the camera flash, that’s about how much light you would see with the naked eye. It has the same cold blue glow as the chandelier, but with a little more musclely power behind it.
I have yet to get an LED lighting appliance that lights with the same force as an ordinary lightbulb fixture (although this comes close), but that would require messing with heretofore unmessed-with quantities of electricity.
It doesn’t come over well with these photos, but I wanted to make an LED design where the lighting element seemed impossibly thin for the amount of light emitted.
The base of the lamp is a "project enclosure" that I got from my dad in an Xmas carepackage filled with spare electronics doodads.
The power supply is a 12v transformer and rectifier assembly that I pulled out of a crappy old boombox a while back (the 12v converted from the power-outlet is equivalent to the 12v that you would get from the 8 D-cell batteries, which are always 1.5v each, follow me?). It’s rare to get an electrical appliance where the rectifier is separate from the main circuit board, so hoard ’em when you find ’em.
The transformer coupled with the fistful of spacing washers makes the project enclosure heavy enough to balance the long lighting arm.
You might notice in the previous image that the base has a red diode as a status light. As the GF said, "Even the status light on that thing is annoying. Why would you have a light to let you know that the light’s not on? That’s the stupidest thing ever."
Hey, the on-off switch is single-throw double-pole (STDP), why would I waste a perfectly good secondary circuit?