Water Torch technology

A "water torch" is a portable oxyhydrogen torch that combines a DC power supply and an electrolytic cell with a pressure gauge and flashback arrestor. Water is decomposed on-demand into oxyhydrogen, obviating the need for separate hydrogen and oxygen tanks. The original was designed in 1962 by William Rhodes and Raymond Henes of the Henes Manufacturing Co.[11] (now Arizona Hydrogen Manufacturing, Inc.).

-Wikipedia