Power supply device

Abstract

To provide a technique capable of suppressing damage to a low-voltage load.SOLUTION: A power supply device includes: a battery; an external interface that is electrically connected to the battery and to which an external device is electrically attached and detached; a voltage converter that is provided between the battery and the external interface; a low-voltage circuit that is branched from an interface connection circuit that connects between an external interface and a voltage converter and being connected to a low-voltage load having a rated voltage lower than a battery voltage; a cutoff circuit provided in the low-voltage circuit to electrically cut off the low-voltage circuit and an interface connection circuit; and a control device for controlling operation of the voltage converter and the cutoff circuit. The control device operates the interruption circuit when the voltage of the interface connection circuit exceeds the rated voltage of the low-voltage load.SELECTED DRAWING: Figure 1

Claims

1. Battery and An external interface that is electrically connected to the aforementioned battery and to which external devices are electrically attached and detached, A voltage converter provided between the battery and the external interface, The upper switching element connected to the positive terminal of the aforementioned battery, A lower switching element is connected in series with the upper switching element and is connected to the negative terminal of the battery and the negative terminal of the external interface, A reactor is provided between the midpoint of the upper switching element and the lower switching element and the positive terminal of the external interface, A voltage converter equipped with, A low-voltage circuit is branched from the interface connection circuit that connects the external interface and the voltage converter, and connected to a low-voltage load having a rated voltage lower than the battery voltage, A disconnection circuit is provided in the low-voltage circuit and includes a first switching element capable of electrically disconnecting the low-voltage circuit and the interface connection circuit. A control device that controls the operation of the voltage converter and the cutoff circuit, Equipped with, The control device is When the voltage of the interface connection circuit exceeds the rated voltage of the low-voltage load, the first switching element of the cutoff circuit electrically cuts off the low-voltage circuit. A first mode in which the upper switching element of the voltage converter is kept ON when the rated voltage of the external device is equal to or greater than the voltage of the battery, A second mode is possible in which, when the voltage of the interface connection circuit is lower than the voltage of the battery, the upper switching element and the lower switching element of the voltage converter are intermittently switched on and off. power supply.

2. The power supply device according to claim 1, wherein the control device electrically conducts the low-voltage circuit using the first switching element when the voltage output from the battery to the interface connection circuit is stepped down by the voltage converter, and the voltage of the interface connection circuit is lower than the rated voltage of the low-voltage load.

3. The power supply device according to claim 1, wherein the control device electrically conducts the low-voltage circuit by the first switching element when the rated voltage of the external device is less than or equal to the rated voltage of the low-voltage load.

4. The interface connection circuit further comprises a second switching element provided in the interface connection circuit for electrically conducting and disconnecting the interface connection circuit, The power supply device according to claim 1, wherein the control device electrically disconnects the interface connection circuit with the second switching element when a short-circuit failure occurs in the upper switching element of the voltage converter.

5. Both the first switching element and the second switching element are provided in a single first semiconductor package. The power supply device according to claim 4.

6. Both the upper switching element and the lower switching element are provided in a single second semiconductor package. The power supply device according to claim 5, wherein the first semiconductor package and the second semiconductor package have the same structure as each other.

7. The power supply device according to claim 1, wherein the control device electrically disconnects the low-voltage circuit with the first switching element when an abnormality occurs in the low-voltage load connected to the low-voltage circuit, regardless of the voltage of the interface connection circuit.

8. The power supply device according to claim 1, wherein the voltage of the battery is the rated voltage of the battery.

9. The power supply device according to claim 1, wherein the external interface is electrically detachable from a charging device that supplies charging power to the battery to the external interface as an external device.

10. The power supply device according to claim 1, wherein the external interface is electrically detachable from an external load that receives discharge power from the battery through the external interface as an external device.

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