A low power, long life LED flashlight circuit

Scouring the Internet for information on LEDs, I accidentally stumbled upon a PDF detailing a flashlight made from PVC. For the torch, he biases ultra-bright LEDs with ballast resistors as described in my LED lighting guide. This is a simple solution, but a with a slightly more complicated circuit we can extend battery life by over ten times!

Download PDF instructions for the inefficient version

PVC flashlight LEDs

Published on Fri, 03 Mar 2006 04:17

Pong in a 3D LED matrix

If you have ever wanted to play pong on a three dimensional display, then this one is for you. There are 1,000 white LEDs in the matrix that can refresh at a rate of 60 fps.

3d LED Pong 3d LED 'dancing'

There are videos included, and they also dance to music. I don’t imagine the videos do the display any justice, though. […]

Published on Tue, 28 Feb 2006 17:23

DIY LED lighting Guide

LED lighting is becoming increasingly popular in fish tanks, case mods, and even household lighting. This article intends to be a comprehensive guide to their advantages, powering them, and creating dimming solutions.

Ultra-bright LEDs

Why use LED lighting?

LED lights are extremely efficient compared to standard incandescent lighting. No other lighting source outputs as many lumens per watt. They are particularly efficient at producing a single color of light. Other light sources have to produce the entire spectrum and optically filter out unwanted colors. However, LEDs can be manufactured to produce only one wavelength of light. This makes them particularly useful in stop lights.

Published on Sun, 26 Feb 2006 04:36

Top performing LEDs

The popularity of my previous article reminded me of some new record setting LEDs.

In the increasingly popular world of light-emitting diodes (LEDs), an emitter’s light output per given input (efficiency), heat management, and small footprint are critical. So if you can make dramatic advancements in just one of these three areas, you’ve done a lot.

LED performance is quantified by the input power (Watts) required and the output intensity (lumen). A lumen measures the luminous flux (light energy passing) through a particular surface. It accounts for light emitted in all directions. The new Luxeon K2 LED breaks all these barriers.

A white light output at a color temperature of 6500 K with 1500 mA of drive current and a forward voltage of 3.85 V produces 140 lm.

This corresponds to 4 W of input power and 35 lumen per Watt. Comparatively, a standard incandescent bulb emits around 855 lumen at 60 Watts or 14 lumen per Watt. Current LEDs perform at about 20 lumen per Watt. Most professionals don’t expect LEDs to be used for mainstream lighting until they reach about 100 lumen per Watt.

Lumileds Lighting's Luxeon K2

Published on Thu, 09 Feb 2006 01:33

Powering LEDs costs mere pennies

Lately the hoopla concerning LED lighting has been overwhelming. Everyone claims this costs mere pennies to power. I decided to put a new twist on a classic science experiment to prove that LEDs do cost pennies to power. Literally.

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Published on Tue, 07 Feb 2006 22:07

LED Flashing sweetheart kit

Valentine’s Day is almost here, so you better have a plan. The LED Flashing Sweetheart Kit may not be a surefire winner, but nothing says love like the labor of your own two hands.

Flashing sweetheart kit photo

Something like this would not be too hard to pull off on your own. If you go ahead and try it, do yourself a favor and get some dinner reservations. You can always cancel if the gift goes over well.[…]

Published on Tue, 24 Jan 2006 02:34

Building a binary clock

If you have ever wanted to build your own binary clock, then Building a binary clock is the best reference I have ever seen. The page lists complete schematics and explains their functionality in detail. In my opinion, it looks a lot geekier straight from the breadboard!

Binary clock on breadboard

Don’t forget to check this diy binary clock out, too.[…]

Published on Thu, 05 Jan 2006 17:28