A nice story, if a little elaborate
Any of the flash bulbs and flash cubes used shreds of flammable metal such as magnesium, generally set off by a very small thin wire that got hot when a current was passed through it. Once the ignition filament was activated it burned out so no more current passed through it. The intensity of the burning magnesium or what ever was not dependent on the voltage of the power supply. The small and brief current that passed through the ignition filament would not have caused the VCR cord to burn the rug.
(the other guy not the one that gave you coochie warts, Tue 14 Aug 2012, 2:06, Reply)