Prioritization circuit and electric power supply system

摘要

There is provided a prioritization circuit which selects one of a system power supply and a secondary battery unit as a selected supply source and the other as a non-selected supply source and which causes supply of electric power with a higher priority from the selected supply source to a power supply unit, wherein the non-selected supply source is connected to the power supply unit through a diode element which generates a voltage drop and the selected supply source supplies electric power to the power supply unit without passing through a diode element.

主权项

1. A prioritization circuit which selects one of a plurality of electric power supply sources as a selected supply source and each of the others as a non-selected supply source, and causes an electric power to be supplied with a higher priority from the selected supply source to a supply target, wherein
Each of the non-selected supply sources is connected to the supply target through a voltage-drop-generating unit which generates a voltage drop, and the selected supply source supplies the electric power to the supply target through a path having a lower voltage drop than that in each of the respective voltage-drop-generating units, and wherein the prioritization circuit comprises: a first terminal connected to an output side of the non-selected supply source; a second terminal connected to an output side of the selected supply source; a first diode element having an anode element connected between the output side of the respective non-selected supply source and the first terminal and a cathode terminal connected between the output side of the selected supply source and the second terminal; a second diode element having an anode terminal connected between the output side of the selected supply source and the second terminal and a cathode terminal connected between the output side of the respective non-selected supply source and the first terminal; and a switching unit which switches the connection of the supply target to one of the first terminal and the second terminal.