Abstract: In a circuit board disposed in parallel to a fixing plane, a guard spacer (abutting member) is disposed on a multi-layer printed circuit board on the side of the fixing plane to suppress deformation of the multi-layer printed circuit board to prevent short circuit if an impact is applied to the circuit board. The guard spacer may be a dummy electronic component or a plate member. An image display using the circuit board is also disclosed.

Abstract: A power-supply unit which comprises a transformer, a full bridge circuit consisting of four arm switches provided on a primary side of the transformer, a rectifier and smoothing circuit including two synchronous rectifier switches provided on a secondary side of the transformer, a choke coil, and a capacitor, an output terminal provided in the rectifier and smoothing circuit, a control circuit controlling ON/OFF of the four arm switches of the full bridge circuit and the two synchronous rectifier switches of the rectifier and smoothing circuit, a resonant inductor consisting of a leakage inductor component of the transformer and a parasitic inductor component of wirings on the primary side of the transformer, and a resonant capacitor consisting of a parasitic capacitor component of the arm switches of the full bridge circuit, and in which the control circuit comprises timing variable means which varies switching timings of the two synchronous rectifier switches of the rectifier and smoothing circuit based on

Abstract: Fuel concentration near a power generator of a DMFC is adjusted by decreasing current taken from the DMFC when the concentration near the power generator of the DMFC is higher than an optimum value and increasing the current taken from the DMFC when the concentration near the power generator of the DMFC is lower than the optimum value. Since the fuel does not come into direct contact with the power generator in the DMFC in a portion from a cartridge to the power generator in the DMFC, drying of the fuel is suppressed. By providing an auxiliary tank capable of storing fuel, concentration of methanol supplied near the power generator of the DMFC is lowered upon activation after long-time storage.

Abstract: A power supply apparatus has a fuel cell unit as a source of input power. A control device limits the output of the fuel cell unit within an operating range of up to a maximum power point, even if a load power is not lower than the maximum power of said fuel cell unit. In addition to the fuel cell, a charge storing device is provided at the output side of the power supply apparatus. The charge storing device is capable of making up a shortage of power of the fuel cell.

Abstract: To provide a smaller and more efficient switching power supply, the switching power supply includes: a high frequency transformer; a primary side switching circuit adapted to switch a current flowing through a primary winding of the high frequency transformer to thereby generate predetermined voltages in a secondary winding and an auxiliary winding of the high frequency transformer; a secondary side rectifier adapted to rectify a voltage generated in the secondary winding to supply the rectified voltage to a load; a charging circuit adapted to rectify a current flowing through the auxiliary winding and to switch the rectified current to thereby charge a secondary battery at a constant current; and a switch, provided between the secondary battery and the load, which supplies, when the voltage supplied to the load is interrupted, the voltage of the secondary battery to the load without going through the high frequency transformer.

Abstract: A fuel cell 1 and an electric double-layer capacitor 2 are parallelly arranged for a power supply. A DC/DC converter 3 steps up voltage of the fuel cell 1 and the electric double-layer capacitor 2, to thereby output power. An output switch 5 is disposed on an output pathway of the DC/DC converter 3. By controlling the output switch 5 with a control IC 4, output power can be switched on and off. When there is a fuel shortage or abnormality in the fuel cell 1, the control IC 4 controls the output switch 5, to thereby intermittently alter the output power. With this configuration, when the power supply is used for a mobile telephone as a portable electronic device connected thereto, a user can confirm whether there is a fuel shortage or a fuel cell abnormality by checking of blinking state of a charge pilot lamp of the mobile telephone.

Abstract: A unidirectional DC-DC converter and method of control thereof. The converter includes a DC power-supply, a buck converter circuit having a first main switching element, a boost converter circuit having a second main switching element, a first snubber capacitor, a first inversely-parallel diode, a control device, and an output diode.

Abstract: A power supply unit in a hybrid structure of a fuel cell and a power storage unit and a control method for the power supply unit, in which a small-size light-weight power storage unit is used and chances of incomplete functioning have been eliminated. In addition to the downsizing of the power storage unit and a reduction of the system price, it also becomes possible to start the fuel cell at high speed and raise the fuel cell temperature quickly, monitor output and remaining mounts of fuel and power, and take measures against fluctuations of output, and provides immediate availability of portable devices like the ones using a conventional secondary cell.

Abstract: A DC backup power supply system having a plurality of loads to which AC from a commercial power source is supplied, and DC power storage means for supplying DC power to the plurality of the loads at the time of a power outage of the commercial power source, said DC backup power supply system including: a control circuit having a first DC backup output for supplying a power from the DC power storage means to the plurality of the loads, including a specific load, only during the power outage of the commercial power source, and a second DC backup output for continuously supplying a power from the DC power storage means to the specific load regardless of the power outage of the commercial power source or sound operation thereof, the control circuit supplying the respective powers from the same DC power storage means to the first and second DC backup outputs.

Abstract: A switching power supply capable of correcting a power factor without using a shunt resistor is provided. The switching power supply includes a rectifier for rectifying an AC power supply, boosting means including a power MOSFET for boosting an output of the rectifier, a smoothing capacitor for smoothing an output of the boosting means, voltage-dividing resistors for detecting a voltage between main terminals of the power MOSFET, a switch for selecting only the voltage by which the power MOSFET is in on-state from voltages detected by the voltage-dividing resistors, an amplifier for amplifying the voltage selected by the switch and outputting the same as a current corresponding value of a current flowing in the power MOSFET, voltage-dividing resistors for detecting the output voltage, and driving means which form a pulse signal based on the current corresponding value and the output voltage for driving the power MOSFET by the pulse signal.

Abstract: Zero volt switching during a light load is performed in such a manner that through an ON/OFF control of switches provided for a full bridge circuit and the synchronous rectifier switches in a rectifier and smoothing circuit, a resonant peak voltage necessary for the zero voltage switching determined by the output current flowing to output terminals, a resonant inductor and a resonant capacitor capacitance is ensured so that an energy accumulated in the rectifier and smoothing circuit is returned to the full bridge circuit so as to act as equivalent as when the output current is increased and to increase the current flowing through the full bridge circuit.

Abstract: In equipment with a built-in fuel cell, there are provided a plurality of secondary cells, and each of the secondary cells has a first state in which an electric power is supplied to a load within the equipment, and a second state in which the electric power that is supplied from the fuel cell is charged, and the first state and the second state is selectively used. The present invention can provide the fuel cell-carried equipment that stably operates due to a power system on which a fuel cell and plural secondary cells are mounted.

Abstract: An object of the invention is to provide a small and low-cost switching power supply unit with a backup function in which a proper circuit construction can be selected by simple method when it is necessary to compensate for the instantaneous drop or power failure and a disk array system having the switching power supply unit. To accomplish the object, a backup unit which can insert and pull out its hot line into a switching power supply unit casing and has a secondary battery and its state monitoring/control unit is built in the unit, and proper charge/discharge management of the secondary battery can be made. When the backup unit is unnecessary, a backup unit formed by a plurality of capacitors whose hot lines can be similarly inserted and pulled out can be built in an enclosing space of the backup unit.

Abstract: A battery and a DC-to-DC converter are contained in a battery pack. When the battery pack is connected to a load by means of a connector and an output voltage reference value, corresponding to the power supply voltage of the load, the output voltage of the battery is converted according to the output voltage reference value by the DC-to-DC converter. The output voltage reference value is set by an output voltage reference value output means in the connector. Furthermore, the converted voltage is supplied to the load via an output voltage line.

Abstract: A method of controlling an electric power source apparatus, which comprises supplying electric power to an electronic device on which a secondary battery is mounted from a power source apparatus having a fuel cell and an auxiliary power source. Electric power is supplied intermittently to a charging terminal of the electronic device by means of a switch for controlling conduction and interruption of an output terminal of the power source apparatus.

Abstract: A first-order feedback control power supply apparatus being arranged in such a manner that when the apparatus is driven under light load condition, a current flowing through an inductor is detected by employing a second CR smoothing filter; when the present load condition is judged as a light load condition based upon the detected inductor current, both upper-sided/lower-sided power MOSFETs and a PWM oscillator are turned OFF so as to be brought into sleep states; when an output voltage of the power supply apparatus is lowered and the lowered output voltage reaches a lower limit threshold of a transient variation detecting circuit, the upper-sided power MOSFET is turned ON to recover the output voltage; and when the output voltage of the power supply voltage reaches a predetermined voltage, the upper-sided power MOSFET is turned OFF so as to be again brought into the sleep state.

Abstract: The DC-DC converter connects a first and a second switching circuit for converting power mutually between direct current and alternating current respectively to a first DC power source and a second DC power source and has a transformer between the AC terminals thereof. Here, between the AC terminals of the second switching circuit and the negative pole terminal of the DC power source, a voltage clamp circuit composed of a series unit of switching devices with a reverse parallel diode and a clamp condenser is connected. An isolated bidirectional DC-DC converter which prevents a reduction in a circulating current at time of buck and an occurrence of a surge voltage at time of voltage boost and realizes highly efficiency, low noise, and miniaturization is provided.

Abstract: When the mobile type information terminal is transferred between an operating state and a standby state, self diagnosis is performed. The fuel cell charges the secondary cells with a normal current of fixed value I1, and when the output voltage of the boost DC/DC converter (when PG=L), the charge current is reduced to the fixed value and aging is performed. After aging is performed for 60 seconds, charging is performed once again performed at the normal fixed value I1. This type of operation is repeated 30 times. During aging, when the output voltage from the boost DC/DC converter is reduced (when PG=L), aging is stopped and after 20 seconds aging is performed again, and this operation is done 10 times. The mobile type information terminal can perform self diagnosis and retrial of regeneration without the user being aware, in which secondary batteries and a fuel cell are loaded.

Abstract: A power-supply device including a marginal check voltage setting circuit that is easily adaptable to downsizing of the device and to configuration using ICs. The power-supply device of this invention includes a marginal check voltage setting circuit that sets a desired marginal check voltage, an error amplifier that delivers output of an error signal, a pulse width modulation oscillator that modulates the pulse width of the output from the error amplifier, a driver circuit that generates driving signal from the pulse signal originating from the pulse width modulation oscillator, and a pair of power semiconductor switching devices that work to step down the input voltage and generate an output voltage based on the driving signal. Furthermore, the power-supply device is also provided with an over-voltage detection circuit and a power-good circuit both circuits being positioned at the output terminal of the marginal check voltage setting circuit.

Abstract: A backup power supply is so constructed that it is provided with multiple DC backup power supplies 111 to 11N, each containing nickel-metal hydride battery, stored upright on the bottom of the disk array unit 100; cooled by cooling air through the vents 1011 for ventilation from the bottom to the top; and connected with the output of the AC/DC converters 121, 122 with the backboard 151. Very compact disk array unit with an uninterruptible power supplying function can be realized.