NOVELTY - The electrolyzer comprises an electrolytic cell (1) with an oxygen and hydrogen generator, connected to a DC power, a relief valve (2) in the cell, a demister (3), a vapor bottle (4) connected to the demister, a regulator (5) connected to the vapor bottle, a flash-back arrester (6) connected to the regulator, a press switch (8) connected to the cell, and a diode block (11).    USE - Electrolysis of water to obtain a large quantity of hydrogen and oxygen in a short time, for domestic use, agricultural use, commercial use or in industrial boilers.    ADVANTAGE - Increased capacity is obtained by increasing the number of cylinders, and compactness and efficiency are achieved by removing a pressure reducing unit of a transformer. Oxygen and hydrogen are extracted and separated from each other in individual cylindrical housings.    DETAILED DESCRIPTION - The electrolyzer comprises:    (i) an electrolytic cell (1) with an oxygen and hydrogen generator, connected to a DC power;    (ii) a relief valve (2) in the cell for controlling pressure;    (iii) a demister (3) for filtering impurities from mix gas from the cell;    (iv) a vapor bottle (4) connected to the demister, for performing spark cut-off in a counter-flowing case of the gas provided from the demister;    (v) a regulator (5) connected to the vapor bottle for controlling the amount of gas ejected through a torch positioned on the end;    (vi) a flash-back arrester (6) connected to the regulator for preventing gas counterflow;    (vii) a press switch (8) connected to the cell for switching electric current in response to an interior pressure of the cell; and    (viii) a diode block (11) for converting AC into DC to then couple the DC with the cell.    An INDEPENDENT CLAIM is also included for a method for electrolyzing water to obtain a large quantity of oxygen and hydrogen.    DESCRIPTION OF DRAWING(S) - The figure shows a block diagram of an apparatus employing an oxygen and hydrogen generator.    Electrolysis cell (1)    Relief valve (2)    Demister (3)    Vapor bottle (4)    Regulator (5)    Flash-back arrester (6)    Press switch (8)    Diode block (11)