| 摘要 |
The invention relates to an always-on system 100 provided with a control unit to govern a power supply switch unit. When one of the main power supply unit 210 or a bypass power supply unit 220 of an external power supply device is to be installed or uninstalled, a user can operate the control unit to switch to the other power supply unit to provide power for loads 300 connected with the always-on system to operate continuously, without interrupting the operation of the load 300. A circuit is included for detecting that the phase of the two power supply units is synchronous. One or both of the power supply units may be an uninterruptible power supply 210. The system may be set to automatically switch power supplies if the power supply in use becomes open circuit. |
