Abstract: The present invention relates to a fuel cell capable of transferring a power generation state and coupling information of the fuel cell to an external apparatus and relates to an information device capable of receiving power and information from the fuel cell. The fuel cell includes a fuel cell stack for generating electricity by an electrochemical reaction of a fuel and an oxidant; a fuel supplier for supplying the fuel to the fuel cell stack; a set of output terminals for outputting electricity generated from the fuel cell stack and for outputting information on a power generation state of the fuel cell; and a power supply information processing unit for applying a voltage level according to the information to any one of the set of output terminals.

Abstract: A fuel cell system possessing a mixing tank for recovering an unreacted fuel, the mixing tank being capable of effectively condensing a stack emission product without increasing its volume. The mixing tank includes a fuel supply port for supplying a concentrated fuel; a fluid inlet port for supplying a fluid discharged from an external fuel cell stack; a chamber for mixing the concentrated fuel with the fluid discharged from the fuel cell stack; a stack supply port for supplying a mixed fuel in the chamber to the fuel cell stack; and a chamber cooling member for cooling the chamber.

Abstract: A module-type fuel cell system including a power module includes a generator installed inside and a power housing having a plurality of connection holes formed sideward, wherein the generator generates electricity through an oxidation-reduction reaction of an oxidizing agent with a hydrogen-containing fuel; a fuel supply module including a fuel supply unit installed inside and a power housing having a plurality of connection holes formed sideward, wherein the fuel supply unit supplies a hydrogen-containing fuel to the generator; an oxidizing agent supply module including an oxidizing agent supply unit installed inside and an oxidizing agent supply housing having connection holes formed sideward, wherein the oxidizing agent supply unit supplies an oxidizing agent to the generator; and a recovery module including a storage space formed therein and a recovery housing having a plurality of connection holes formed sideward, wherein the storage space recovers an unreacted fuel generated in the generator, wherein th

Abstract: A battery pack that is charged with power generated in an external power generator and supplies battery power to an external load in parallel with the external power generator, and a power receiving device of a portable electronic device that receives and supplies battery power to an external load in parallel with the external power generator, the battery pack including: a battery cell to discharge power based on a charged amount of electric charge; an external power input terminal to receive power from an external power generator; a power output terminal to supply power to an external load; and a voltage transforming circuit to transform voltage of the power received through the external power input terminal to transfer the transformed voltage to the power output terminal.

Abstract: The disclosed is a density sensing device of a fuel cell system and a fuel cell system having the density sensing device. The density sensing device includes a density sensor that includes a collision sensor and a variable resistor coupled to the collision sensor. The collision sensor is dipped into a fuel solution, and the collisions of molecules of the fuel solution are detected in the collision sensor. The resistance of the variable resistor caries depending on an amount of the collision detected by the collision sensor. The resistance further is converted to a density by the use of a table that includes a relationship between resistance and density. The density sensing device can further include a sensor driver. The sensor driver can be a piezoelectric member that is attached to the collision sensor. The collision sensor vibrates together with the piezoelectric member when a driving signal is applied to the piezoelectric member, which improves the accuracy of the measurement of the density.

Abstract: A method and an apparatus for controlling the operation of a fuel cell system. The method can include, actively controlling the fuel cell system without a fuel concentration sensor by: measuring an output voltage, an output current, and a temperature of a fuel cell stack; obtaining a first fuel feeding amount corresponding to the measured output values; comparing a reference temperature corresponding to the measured output values with the measured temperature; and obtaining a second fuel feeding amount by compensating the first fuel feeding amount with a value corresponding to difference between the reference temperature and the measured temperature.

Abstract: A fuel cell with a recovering unit and a method of driving the same are disclosed. In one embodiment, the fuel cell includes i) an electric generator to generate electricity based on electrochemical reaction, ii) a recovering unit to recover and mix the fuel, unreacted fuel, and gas and water produced by the electrochemical reaction, and supply the mixed fuel to the electric generator, wherein the recovering unit comprises a valve, configured to discharge gas, which is selectively opened and closed depending on the operation of the fuel cell. With this configuration, the gas or the fuel is not introduced into the electric generator, even though the recovering unit is inclined or turned over. Further, even though the fuel cell is not in use for a long time, the mixed fuel is prevented from evaporating through the discharging pipe.