The field coil of the alternator is switched on and off by an FET transistor which is pulsed by a 555 timer circuit. This produces a composite waveform which produces an impressive rate of electrolysis using just tap water or rainwater with no additives whatsoever： The tubes in this replication are made of 316L grade stainless steel， five inches long although Stan’s tubes were about three times that length. The outer tubes are 1 inch in diameter and the inner tubes 3/4 inch in diameter. As the wall thickness is 1/16 inch， the gap between them is between 1 mm and 2 mm. The inner pipes are held in place at each end by four rubber strips about one quarter of an inch long. The container is made from two standard 4 inch diameter plastic drain down-pipe coupler fittings connected to each end of a piece of acrylic tube with PVC solvent cement. The acrylic tube was supplied already cut to size by Wake Plastics， 59 Twickenham Road， Isleworth， Middlesex TW7 6AR Telephone 0208-560-0928. The seamless stainless steel tubing was supplied by