Power supply control device

A power supply control device that is used in an on-board system including:

• a power source unit configured to supply power;
• a power path through which power that is based on the power source unit is transmitted;
• and a power storage unit different from the power source unit, and controls power supply from the power storage unit, the power supply control device comprising:
• a first conductive path to which a voltage that is based on output of the power storage unit is applied;
• an element unit that is electrically connected at one end to the first conductive path;
• a second conductive path that is electrically connected to the other end of the element unit, and forms a current-carrying path between the element unit and the power path;
• a voltage conversion unit that is connected in parallel with the element unit between the power storage unit and the power path, and is configured to perform a conversion operation of stepping up or down an input voltage that is based on power from the power storage unit;
• a third conductive path that is electrically connected to the voltage conversion unit between the voltage conversion unit and the power path;
• and
• a control unit configured to control the voltage conversion unit,
• wherein the element unit is capable of allowing flow of a current to the power path side via the element unit itself and cutting off flow of a current to the power storage unit side via the element unit itself, and
• the control unit stops the voltage conversion unit when supply of power from the power source unit to the power path is in a normal state different from a failure state, and causes the voltage conversion unit to start the conversion operation when the failure state is entered.