Power supply device supplying limited DC power to load based on ground fault detection

摘要

A power supply device supplies DC power to a load and includes: a shunt resistor connected in series to a low-potential side of the load; a power supply control device for controlling a power supply state to the load according to an amount of a voltage drop across the shunt resistor; a ground fault detection element connected in series to the low-potential side of the load to cause a voltage drop; and a limiting device for limiting a supply of power by the power supply control device by determining that a ground fault occurs in a case where an amount of a voltage drop, which occurs when a detection current flows through the ground fault detection element, is less than a predetermined threshold.

主权项

1. A power supply device configured to supply DC power to a load, comprising:
a shunt resistor connected in series to a low-potential side of the load; a power supply control device for controlling a power supply state to the load according to an amount of a voltage drop across the shunt resistor and supplying a drive current; a ground fault detection element connected in series to the low-potential side of the load to cause a voltage drop, the ground fault detection element receiving the drive current and a detection current, which is different from the drive current; and a limiting device for determining whether an amount of the voltage drop, which occurs when the detection current flows through the ground fault detection element, is less than a predetermined threshold, and when the voltage drop is less than the predetermined threshold, limiting a supply of power by the power supply control device by determining that the ground fault occurs.