Computer system selectively directing power to a battery from either a backup power supply or a normal power supply based on a reduction of voltage measured from one or more detection circuits

A power supply system comprising:

• a normal power supply device that includes a first converter configured to convert a first alternating-current voltage into a first direct-current voltage;
• and
• a backup power supply device that is electrically coupled to the normal power supply device,
• wherein the backup power supply device includes:
• a second converter that converts a second alternating-current voltage inputted into the backup power supply device into a second direct-current voltage;
• a battery that is charged by the second direct-current voltage and configured to output a third direct-current voltage;
• a first detector configured to receive an output of the first converter from the normal power supply device and output a first detection signal when a reduction of the first direct-current voltage outputted from the first converter is detected;
• a switch that is electrically coupled to the normal power supply device, and configured to selectively supply either the second direct-current voltage outputted from the second converter or the third direct-current voltage outputted from the battery to the normal power supply device by switching, when the first detection signal is received;
• a second detector that outputs a second detection signal when a reduction of the second alternating-current voltage outputted from the second converter is detected is detected;
• a control circuit coupled to a computer device operated by the normal power supply device or the backup power supply device and configured to:
• receive a termination notification on shutdown of the computer device from the computer device, after notifying the computer of the output of the first and second detection signals, and
• control the switch so that an output of the battery is not electrically coupled to the normal power supply device, after a predetermined time period after the termination notification is received.

A backup method for a normal power supply device including a first converter configured to convert a first alternating current voltage into a first direct-current voltage, the backup method being executed by a backup power supply device that is electrically coupled to the normal power supply device, the backup method comprising:

• converting, by a second converter, a second alternating-current voltage inputted into the backup power supply device into a second direct-current voltage;
• outputting, by a battery that is charged by the second direct-current voltage, a third direct-current voltage;
• receiving, by a first detector, an output of the first converter from the normal power supply device, and outputting a first detection signal when a reduction of the first direct-current voltage outputted from the first converter is detected;
• selectively supplying, by a switch that is electrically coupled to the normal power supply device, either a second direct-current voltage outputted from a second converter or a third direct-current voltage outputted from a battery to the normal power supply device by switching, when the first detection signal is received;
• outputting, by a second detector, a second detection signal when a reduction of the second alternating-current voltage outputted from the second converter is detected;
• receiving, by a control circuit coupled to a computer device operated by the normal power supply device or the backup power supply device, a termination notification on shutdown of the computer device from the computer device, after notifying the computer of the output of the first and second detection signals;
• and
• controlling the switch so that an output of the battery is not electrically coupled to the normal power supply device, after a predetermined time period after the termination notification is received.

A non-transitory computer-readable recording medium storing a program that causes a processor included in a backup power supply device that is electrically coupled to a normal power supply device, the normal power supply device including a first converter configured to convert a first alternating current voltage into a first direct-current voltage, to execute a process, the process comprising:

• converting, by a second converter, a second alternating-current voltage inputted into the backup power supply device into a second direct-current voltage;
• outputting, by a battery that is charged by the second direct-current voltage, a third direct-current voltage;
• receiving, by a first detector, an output of the first converter from the normal power supply device, and outputting a first detection signal when a reduction of the first direct-current voltage outputted from the first converter is detected;
• selectively supplying, by a switch that is electrically coupled to the normal power supply device, either a second direct-current voltage outputted from a second converter or a third direct-current voltage outputted from a battery to the normal power supply device by switching, when the first detection signal is received;
• outputting, by a second detector, a second detection signal when a reduction of the second alternating-current voltage outputted from the second converter is detected;
• receiving, by a control circuit coupled to a computer device operated by the normal power supply device or the backup power supply device, a termination notification on shutdown of the computer device from the computer device, after notifying the computer of the output of the first and second detection signals;
• and
• controlling the switch so that an output of the battery is not electrically coupled to the normal power supply device, after a predetermined time period after the termination notification is received.