| 摘要 |
PROBLEM TO BE SOLVED: To provide an overvoltage protection device capable of continuously blocking an AC power supply with certainty without human operations when an overvoltage of an AC power supply is detected, and that is small in size and light in weight.SOLUTION: An overvoltage protection device comprises: an input end AC_IN for an AC power supply; an output end AC_OUT for the AC power supply, connected to a protection target device; wires L1 and L2 coupling between the input end AC_IN and the output end AC_OUT; a normally-closed contact relay RY provided to the wire L1; an input state detector 2 connected to the wire L1, and configured to detect an overvoltage of the AC power supply; a relay drive circuit 3 coupled with the input state detector 2 in an electrically-insulated state, and configured to drive the relay RY; and a battery BAT supplying a power to the relay drive circuit 3. When the input state detector 2 detects the overvoltage, the relay drive circuit 3 drives and opens the normally-closed contact relay RY, and keeps the contact point of the relay in a released state by the power supply of the battery BAT. |
