Abstract: A DC to DC converter includes: first and second switching elements connected at a first connection point between a first input/output terminal and a first ground terminal; third and fourth switching elements connected at a second connection point between the first input/output terminal and the first ground terminal; a resonant capacitor and a resonant inductor connected in series between the first and second connection points; fifth and sixth switching elements connected at a third connection point between a second input/output terminal and a second ground terminal; seventh and eighth switching elements connected at a fourth connection point between the second input/output terminal and the second ground terminal; a transformer; and a control circuit. The control circuit is operable to adjust the pulse waveforms for switching the fifth to eighth switching elements when voltage at the second input/output terminal is stepped down and output from the first input/output terminal.

Abstract: A charge-discharge device includes a DC-DC converter configured to be electrically connected to a secondary battery, an inverter electrically connected to the DC-DC converter, a main charging terminal electrically connected to the inverter, a voltage detector for detecting a voltage of the main charging terminal, and a control circuit electrically connected to the DC-DC converter, the inverter, and the voltage detector.

Abstract: A DC to DC converter includes: first and second switching elements connected at a first connection point between a first input/output terminal and a first ground terminal; third and fourth switching elements connected at a second connection point between the first input/output terminal and the first ground terminal; a resonant capacitor and a resonant inductor connected in series between the first and second connection points; fifth and sixth switching elements connected at a third connection point between a second input/output terminal and a second ground terminal; seventh and eighth switching elements connected at a fourth connection point between the second input/output terminal and the second ground terminal; a transformer; and a control circuit. The control circuit is operable to adjust the pulse waveforms for switching the fifth to eighth switching elements when voltage at the second input/output terminal is stepped down and output from the first input/output terminal.

Abstract: An in-vehicle power supply device includes an electric generator, a main power supply, a DC/DC converter, a power storage unit, and a controller for controlling the DC/DC converter. The DC/DC converter stores regenerative electric power generated by the electric generator, and discharges the stored regenerative electric power to the main power supply and the load. The controller stops the DC/DC converter when a charging-status value is not larger than a predetermined lower limit value. Additionally, the controller activates the DC/DC converter when the charging-status value is larger than the lower limit value and the vehicle ends deceleration; and activates the DC/DC converter when a speed of the vehicle is not lower than a predetermined speed and an accelerator position of the engine is not larger than a predetermined accelerator position even if the charging-status value is not larger than the predetermined lower limit value.

Abstract: An in-vehicle power supply device includes an electric generator, a main power supply, a DC/DC converter, a power storage unit connected with the electric generator via the DC/DC converter, and a controller for controlling the DC/DC converter. The DC/DC converter is operable to store, in the power storage unit, regenerative electric power generated by the electric generator, and to discharge the stored regenerative electric power from the power storage unit to the main power supply and the load. The controller is operable to stop the DC/DC converter when a charging-status value indicating a charging status of the power storage unit is not larger than a predetermined lower limit value. The controller is operable to activate the DC/DC converter when the charging-status value is larger than the lower limit value and the vehicle ends deceleration.

Abstract: A vehicle power supply device is provided which is capable of improving fuel efficiency by lengthening a period of no-idling even if a main power supply thereof is deteriorated. The device is configured for use in a vehicle having an engine and a load, and includes an electric generator, a main power supply, a starter, a first switch, a power storage part, a second switch, and a control part. In the case of the main power supply being deteriorated, the control part causes the main power supply to supply electric power thereof to the load in the period of no-idling of the vehicle, and the control part controls, when the engine is restarted, such that the starter is driven on both the electric power of the main power supply and regenerative electric power of the power storage part, with the first switch being OFF and the second switch being ON.

Abstract: An electrical generator is connected with a first end of DC/DC converter and an electric storage section is connected with a second end of the converter. An output voltage detecting circuit is connected to the electrical generator, and a control circuit is connected to both the DC/DC converter and the output voltage detecting circuit. The electrical generator raises an adjusting voltage Va at an output terminal to a first predetermined output voltage Vdc1 at a timing when regenerated electric power is produced. Control circuit 35 controls an output voltage Vd to be a lower control voltage Vdk which is lower than the first predetermined output voltage Vdc1. The lower control voltage Vd is set at a value which allows a main power supply to be charged maximally with the regenerated electric power.

Abstract: A load and a first storage battery are connected to a generator, and a second storage battery is connected to the generator via a DC/DC converter, wherein a controller connected to the DC/DC converter, receiving a regeneration signal emitted from outside, controls the DC/DC converter so that the voltage of an input/output terminal becomes the first target voltage that is lower by the first fixed value than the voltage of input/output terminal to which the generator is connected in the DC/DC converter at the time in order to charge the second storage battery, and when regeneration signal reception is ended, the DC/DC converter is controlled so that the voltage of the input/output terminal becomes the second target voltage that is higher by the second fixed value than the voltage of input/output terminal at the time, and thereby, it is possible to enhance the regenerative power recovering efficiency irrespective of conditions during braking.

Abstract: A DC-DC converter includes a control circuit which can change the target voltage of the reference voltage source. At the start-up of the DC-DC converter, the PWM control circuit controls so that the first switching element gradually increases the on-off ratio from a minimum on-off ratio; that the second switching element is placed in the OFF state, and that the target voltage is set higher than the normal operating voltage. When the start-up operation is completed, the PWM control circuit controls so that the second switching element starts to turn on and off, and that the target voltage is returned to the normal operating voltage.