Lighting Fundamentals: Special Effects LEDs
The market is now filled to overflowing with unique LED products. Among them are special effects LEDs. These are essentially regular LEDs with built-in effects chips, and outwardly look no different. There are several popular types (among others):
- blinking LEDs
- strobe LEDs produce brief, bright flashes like strobe lights
- flickering LEDs flicker like gently fluttering candles
- fader LEDs, a.k.a. "breathing" LEDs, gradually increase and decrease in brightness
All of the above effect LEDs come in a full array of colors. In addition, there are color cycling LEDs, which are RGB LEDs pre-programmed with a sequence of flashes and fades in various color combinations.
Some special effects LEDs may have multiple applications. The effect they simulate can vary according to context. For instance, multiple flickering LEDs in combination can simulate firelight from a fireplace. But then, a cool white flickering LED is perfect for a welding effect, and far more economical than a commercial effects circuit.
Mix and Match
Most all of the effects LEDs come in large 5 mm DIPs. If you need a smaller form factor, it's possible to make plain LEDs flicker and fade by connecting them in series with effects LEDs. This is how I created the campfire.
You can even combine two effects chips to produce some random, unpredictable results; for instance, I simulated a B&W television by combining fader and flicker LEDs.