Abstract: A capacitor device includes a capacitor unit, a voltage-dividing circuit for outputting a divided voltage obtained by dividing a voltage of the capacitor unit, and a comparator circuit. The comparator circuit causes the charge circuit to operate such that the voltage of the capacitor unit reaches a full-charge voltage. The voltage-dividing circuit includes a semiconductor switching element, and outputs a divided voltage. A control circuit is operable to determine the full-charge voltage to be a high-temperature full-charge voltage by turning off the first semiconductor switching element when a temperature at the capacitor unit exceeds a reference temperature. The control circuit is operable to determine the full-charge voltage to be a low-temperature full-charge voltage that is higher than the high-temperature full-charge voltage by turning on the first semiconductor switching element when the detected temperature is not higher than the reference temperature.

Abstract: A DC blocking capacitor and a resistor are coupled in series, and coupled in parallel with an electricity storing section. An ON/OFF circuit and a peak voltage holding circuit are coupled in parallel with the resistor. A current sensing section is coupled in series with the storing section, with its output supplied to the peak current holding circuit. Current from a positive to a negative electrode of the storing section is referred to as a positive direction. The ON/OFF circuit is turned on when the current flows in a negative direction, and is turned off when the current flows in the positive direction. An internal resistor of the storing section is found based on a peak voltage and a peak current resulting from the control and held by the respective circuits. A degree of degradation of the electricity storing section is determined with this internal resistor.

Abstract: A charging apparatus suppresses rise in temperature of an internal chip of a charging element. The output signal obtained from a current detecting portion for detecting charging current to a capacitor and from a voltage detecting portion for detecting a difference between a voltage (VC) of capacitor and a voltage corresponding to DC power supply is integrated by integrator. The charging is carried out by controlling power of a charging element to a predetermined value using an output signal of the integrator and at a time near the completion of the charging, the charging element is controlled by constant-voltage-control-circuit so as to charge the capacitor up to a predetermined voltage. Consequently, the maximum temperature inside the charging element is reduced, thereby providing a charging apparatus with high reliability.

Abstract: Electric storage device is provided which is capable of smoothly charging storage elements and reliably detecting an overvoltage of each of the storage elements. Electric storage device includes charging/discharging limiting circuit. Charging/discharging limiting circuit includes charge element, discharge, control unit, charging current detection unit, voltage detection unit, valuable reference voltage source, and voltage comparison unit. A magnitude of valuable reference voltage source that is connected to an input terminal on a first side of voltage comparison unit is adjusted by charging current detection unit. Detection signal from the voltage detection unit is given to an input terminal on a second side of voltage comparison unit.

Abstract: A vehicle power supply device has a capacitor unit including capacitors storing auxiliary power; a temperature sensor; a charge circuit; a capacitor-unit current detector; a capacitor-unit voltage detector; a controller; a storage; and a determination unit. The determination unit determines the degradation level of the capacitor unit based on at least one of an internal resistance standard value and a corrected calculated value of capacitance. This structure determines degradation of the vehicle power supply device more accurately than ever, so that the device can be used until the end of the actual life.

Abstract: A voltage detector for a storage element that includes a positive electrode and a negative electrode, both being biased to a positive voltage, is disclosed. The voltage detector includes a first PNP transistor of which emitter terminal is connected to the negative terminal and its base terminal is connected to its collector terminal, a voltage-current converter of which first end is connected to the positive electrode, a second PNP transistor of which emitter terminal is connected to a second end of the converter and its base terminal is connected to the base terminal of the first PNP transistor, a current source connected to the collector terminal of the first PNP transistor for drawing a current from the collector terminal, a current sensing circuit connected to the collector terminal of the second PNP transistor for sensing a collector current, and a voltage output circuit for outputting a voltage across the positive electrode and the negative electrode based on an output from the current sensing circuit.

Abstract: DC blocking capacitor and resistor are coupled in series with electricity storing section at its both ends, and ON/OFF circuit is coupled in parallel with resistor. Peak voltage holding circuit is coupled in parallel with ON/OFF circuit, and current sensing section is coupled in series with storing section, and an output from current sensing section is supplied to peak current holding circuit. In the structure of the storage device discussed above, a flowing direction of an electric current from a positive electrode to a negative electrode of storing section is referred to as a positive direction. ON/OFF circuit is controlled such that circuit is turned on when the current flows in a negative direction, and such that it is turned off when the current flows in the positive direction. An internal resistor of storing section can be found based on a peak voltage resulting from the control and held by circuit and a peak current resulting from the control and held by circuit.

Abstract: The A/D conversion apparatus and the vehicle power-supply device using the apparatus calculate errors at a plurality of reference voltages and reference errors prior to error correction. Each reference error is applied to a digital-output range that is divided by digital output corresponding to the reference voltages. In the calculation, when the errors obtained at adjacent reference voltages have same signs, the reference error is determined as an average of the errors obtained at adjacent reference voltages; on the other hand, when the errors obtained at adjacent reference voltages have different signs, the reference error is determined to be zero. The apparatus provides a corrected digital output by subtracting the reference error—which is applied to the digital-output range including the digital output—from the digital output corresponding to analog input voltage.

Abstract: A vehicle power supply device has a capacitor unit including capacitors storing auxiliary power; a temperature sensor; a charge circuit; a capacitor-unit current detector; a capacitor-unit voltage detector; a controller; a storage; and a determination unit. The determination unit determines the degradation level of the capacitor unit based on at least one of an internal resistance standard value and a corrected calculated value of capacitance. This structure determines degradation of the vehicle power supply device more accurately than ever, so that the device can be used until the end of the actual life.

Abstract: Electric storage device is provided which is capable of smoothly charging storage elements and reliably detecting an overvoltage of each of the storage elements. Electric storage device includes charging/discharging limiting circuit. Charging/discharging limiting circuit includes charge element, discharge element, control unit, charging current detection unit, voltage detection unit, valuable reference voltage source, and voltage comparison unit. A magnitude of valuable reference voltage source that is connected to an input terminal on a first side of voltage comparison unit is adjusted by charging current detection unit. Detection signal from the voltage detection unit is given to an input terminal on a second side of voltage comparison unit.

Abstract: A vehicle source device capable of performing a more accurate temperature-rise corresponding to the ability of the capacitor is provided. The correlation of the temperature and the internal resistance corresponding to the ability of the current capacitor in time of activation is obtained in advance, the internal resistance is obtained for every repetition of charge/discharge, and the temperature of the inside of the capacitor is obtained from the correlation. Since the accurate temperature of the inside of the capacitor is obtained, the capacitor is accurately temperature-raised to the target temperature.

Abstract: In a voltage monitor that measures voltages applied to the terminals of each of a plurality of capacitors constituting a storage section, the each voltage applied to a connecting point between terminals of the capacitors in charging operation, is divided by resistors and the divided voltage is fed into a selector switch. The resistance values used for dividing the each voltage are determined in advance so that a short-circuit between adjacent input terminals of the selector switch allows the divided voltage to have a voltage shift remarkably larger or smaller than the divided voltage obtained under the normal charging operation.

Abstract: A charging apparatus suppresses rise in temperature of an internal chip of a charging element. The output signal obtained from a current detecting portion for detecting charging current to a capacitor and from a voltage detecting portion for detecting a difference between a voltage (VC) of capacitor and a voltage corresponding to DC power supply is integrated by integrator. The charging is carried out by controlling power of a charging element to a predetermined value using an output signal of the integrator and at a time near the completion of the charging, the charging element is controlled by constant-voltage-control-circuit so as to charge the capacitor up to a predetermined voltage. Consequently, the maximum temperature inside the charging element is reduced, thereby providing a charging apparatus with high reliability.

Abstract: A power supply device has a capacitor unit in which capacitors are interconnected in series, a charging unit for charging the capacitor unit at a constant current, a detecting unit for detecting voltage on the high potential side of each of the capacitors, a determining unit for determining the existence of an abnormality based on the voltage detected by the detecting unit. The determining unit determines the abnormality when the difference between respective voltages on the high potential sides of some adjacent capacitors exceeds upper-limit voltage value Va, when the difference is lower than lower-limit voltage value Vb, or when a voltage is negative.

Abstract: In a voltage monitor that measures voltages applied to the terminals of each of a plurality of capacitors constituting a storage section, the each voltage applied to a connecting point between terminals of the capacitors in charging operation, is divided by resistors and the divided voltage is fed into a selector switch. The resistance values used for dividing the each voltage are determined in advance so that a short-circuit between adjacent input terminals of the selector switch allows the divided voltage to have a voltage shift remarkably larger or smaller than the divided voltage obtained under the normal charging operation.