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 . <EOS>