| 摘要 |
<p>A phase synchronization circuit for AC voltage includes an optical phase detection unit that outputs a phase detection signal by detecting an externally provided first AC voltage; a power failure detection unit that outputs a power failure signal by detecting the power failure condition of the first AC voltage; a control unit that selectively activates a selection signal according to the control of the power failure detection signal and outputs a phase control signal according to the control of the phase detection signal; a second AC voltage generation unit that generates a second AC voltage to have the same phase of the first AC voltage when outputting a second AC voltage according to the control of the phase control signal; and a selection unit that outputs either the first AC voltage or the second AC voltage according to the control of the selection signal.</p> |
