Updated: Apr 24
For a production of the Wizard of Oz, we needed practical flames that could burst forth when the wizard projection appears:
These are silk flames, with twin 10w RGB lights on either side and a reconstructed 5W 2700K spot directly underneath the flames.
the brightness, fan strength, and flu valve opening can all be controlled individually using DMX lighting control signals that are sent via a radio transmitter to the flames. A 12v adapter is used for the lighting and circuitry (although a battery pack could also be used) and the fans each require a 110v AC outlet. I used an extension cord to supply everything needed in this case.
The dimmable flame brightness is controlled by a MOSFET, the fan is controlled by a relay I built into the fan's power supply circuitry, and a servo opens and closes the flu to any percentage desired. The brains are rf-nano boards fed by an rf-nano transmitter that reads DMX signals to supply appropriate commands to the flame urns, among other set pieces.
Here is a close-up demo of one of the urns I made after the show. I cut up tiny bits of napkin and threw them in before powering the urn up to create the spark effect. You can see my stage lighting software in the background of the video raising and lowering 2 channels to control the effect.
For those curious, here is a shot at the underside of the urn, where the flu mechanism and brains are located.