Asked by: John Mitchell, Glasgow
In a computerised firework display, the pyrotechnics are detonated by electric matches, or e-matches. The e-match head contains a zirconium compound that ignites readily when heated, the heat coming from a coil of wire encasing the head.
The e-matches are triggered remotely from controllers called electronic firing panels, which have banks of switches assigned either to individual pyrotechnics or batches to be fired simultaneously.
The more advanced panels run automatically from computer code. This is often programmed using specialist pyrotechnic software and then downloaded to the panel before the display.
Using software to launch a display is open to error, however, as seen at the San Diego 2012 Fourth of July celebrations when a glitch triggered all the fireworks at once.