US Patent 7159994 - System and method for generating a flickering flame effectThe generation of a flickering flame effect is important in entertainment applications, since it provides a mechanism for simulating the flicker of a candle without actually using a candle. This is important since it provides numerous safety benefits as well as an ability to keep the artificial flame "burning" in the presence of significant air pressure variations.
One type of device that generates an artificial flame is commonly known as a "wiggle wire ball." Specifically, this device is a relatively large ball that has a flat filament, wherein the current in the filament takes a random path which alters from time to time, thereby simulating a flickering flame effect.
Another such device includes a series of orange and white LEDs that are cast in resin having a flame shaped surface. A current supplied to the LED's in a particular sequence gives rise to a flickering flame effect.
Yet another device is commonly referred to as a "silk flame." The silk flame includes a piece of silk that is blown upwards by a fan, causing it to undulate. A light projected on the silk piece is reflected off of the silk while it is moving, thereby creating a flickering flame effect. Another device for generating an artificial flickering flame effect is a lamp having a flicker wherein the flicker circuit is used to modulate the glowing light source within the bulb, thereby giving an appearance of a candle burning inside a lantern or a sconce.
Another flickering flame device is a light bulb inside a flame shaped plastic object, which has wires incorporated into it. The wires interact with electromagnets causing the flame shaped object to tilt from side to side under control of an electronic circuit.