NOVELTY - A hydrogen production system (41) comprises a reaction chamber (44, 46) having an inlet and outlet; a gas collection chamber disposed proximate the reaction chamber; and a regulator coupled to the gas collection chamber. The regulator controls the flow of a reactant to the reaction chamber in response to the pressure in the gas collection chamber.    USE - The hydrogen production system is used for generating hydrogen used for fuel cell system (claimed) that supplies electrical energy to power the portable electrical devices, e.g. computer or computational device, cell phone, personal digital assistant, portable power tool or any other hand held electrical device.    ADVANTAGE - Regulating the production of the fuel supplied to the cell provides increased safety, since the fuel can be stored in a stable, inert form such as sodium borohydride (NaBH4); and simpler control, since it is easier to regulate the flow of an aqueous solution like NaBH4 than hydrogen gas.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) a fuel cell system comprising an anode; a cathode; a proton exchange membrane disposed between the anode and cathode; and the production system coupled to the anode;    (2) a method of making a production system comprising creating a reaction chamber having an inlet and outlet; creating a collection chamber (58) coupled with the reaction chamber; and creating a regulator, which controls the flow of reactant to the reaction chamber in response to the pressure in the collection chamber; and    (3) a method of regulating a production system, comprising reacting a reactant in a reaction chamber having an inlet and outlet and creating a gas; collecting the gas in a collection chamber coupled with the reaction chamber; sensing the pressure of the gas in the collection chamber; sensing a reference pressure; and regulating the flow of reactant to the reaction chamber based on the differential pressure between the reference pressure and the collection chamber pressure.    DESCRIPTION OF DRAWING(S) - The figure illustrates a cross sectional perspective view of a hydrogen production system.    Hydrogen production system (41)    Reaction chamber (44, 46)    Hydrophilic screens (52)    Collection chamber (58)    Conduit (60)