VOLTAGE REGULATOR AND IN-VEHICLE BACKUP POWER SUPPLY

The present disclosure realizes a configuration capable of setting and changing the value of a voltage that is output from a voltage regulator, while suppressing an increase in the size of an apparatus and keeping the apparatus from being complex. A control unit of a voltage regulator operates to switch a state of each port to either a first state or a second state. An input circuit unit applies a voltage corresponding to the combination of the first states at the ports to the base of a transistor. Electricity flows through the transistor when at least one of the ports is in the first state. A switch is turned on when electricity flows through the transistor. A Zener diode sets an output voltage applied to a second conductive path to a voltage corresponding to a voltage applied to the base of the transistor.