An uninterruptible power supply for supplying power to a load circuit from a power source, the uninterruptible power supply comprising: an auxiliary power supply for supplying power to the load circuit in the event of an interruption in supply of power from the power source; a charging/discharging circuit operable to charge the auxiliary power supply from the power source and to discharge the auxiliary power supply through the load circuit, the charging/discharging circuit comprising a switch for connecting the uninterruptible power supply to, and disconnecting the uninterruptible power supply from, the load circuit; a voltage monitor configured to monitor a voltage that is indicative of the supply of power from the power source to the uninterruptible power supply; and a controller configured to: generate a control signal for shutting down the load circuit in response to an interruption in the supply of power from the power source, based on the voltage monitored by the voltage monitor; monitor an operational status of the load circuit after having generated the control signal to determine whether the load circuit has shut down; on determining that the load circuit has shut down, cause the charging/discharging circuit to be disconnected from the load circuit by opening the switch; and after the interruption in supply of power from the power source has ended, cause the charging/discharging circuit to be reconnected to the load circuit by closing the switch. an auxiliary power supply for supplying power to the load circuit in the event of an interruption in supply of power from the power source; a charging/discharging circuit operable to charge the auxiliary power supply from the power source and to discharge the auxiliary power supply through the load circuit, the charging/discharging circuit comprising a switch for connecting the uninterruptible power supply to, and disconnecting the uninterruptible power supply from, the load circuit; a voltage monitor configured to monitor a voltage that is indicative of the supply of power from the power source to the uninterruptible power supply; and a controller configured to: generate a control signal for shutting down the load circuit in response to an interruption in the supply of power from the power source, based on the voltage monitored by the voltage monitor; monitor an operational status of the load circuit after having generated the control signal to determine whether the load circuit has shut down; on determining that the load circuit has shut down, cause the charging/discharging circuit to be disconnected from the load circuit by opening the switch; and after the interruption in supply of power from the power source has ended, cause the charging/discharging circuit to be reconnected to the load circuit by closing the switch. generate a control signal for shutting down the load circuit in response to an interruption in the supply of power from the power source, based on the voltage monitored by the voltage monitor; monitor an operational status of the load circuit after having generated the control signal to determine whether the load circuit has shut down; on determining that the load circuit has shut down, cause the charging/discharging circuit to be disconnected from the load circuit by opening the switch; and after the interruption in supply of power from the power source has ended, cause the charging/discharging circuit to be reconnected to the load circuit by closing the switch.