| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply switching device capable of switching a power supply without stopping the supply of power to a load.SOLUTION: A power supply switching circuit comprises: a first power conversion circuit connected between a first power supply and a load, and that converts a power from the first power supply into a voltage by which the load can be operated; a second power supply connected with the load via a switch; and a control circuit that detects an output voltage from the first power supply and an output voltage from the first power conversion circuit, and outputs a control signal for opening and closing the switch to the switch. When the output voltage from the first power supply is reduced lower than a first threshold, the control signal for turning on the switch is transmitted to the switch to turn on the switch. When the output voltage from the first power conversion circuit is raised higher than a second threshold, a control signal for turning off the switch is transmitted to the switch to turn off the switch. |
