Circuit breaker

A circuit breaker, comprising:

• a vacuum interrupter including a fixed contact and a movable contact;
• a driving unit including a main shaft rotatable between a closing position where the movable contact contacts the fixed contact and an opening position where the movable contact is separated from the fixed contact, and a plurality of links interlocked with the main shaft, and configured to supply a driving force to open and close the vacuum interrupter;
• a power transmission unit disposed between the driving unit and the vacuum interrupter, and configured to transmit a driving force of the driving unit to the movable contact;
• an over-current relay configured to detect a fault current and to output a trip signal to break a large-scaled current conduction;
• a trip unit disposed at one side of the driving unit, and configured to generate and transmit a mechanical operation force to the driving unit when a trip signal is output from the over-current relay;
• and
• a Thomson drive including a Thomson coil, and a repulsive plate configured to be spaced from the Thomson coil by an electromagnetic repulsive force when a power is applied to the Thomson coil, the Thomson drive configured to be connected to the power transmission unit to rotate the main shaft to an opening position by a movement of the repulsive plate when a power is applied to the Thomson coil, or the Thomson drive configured to be provided at the trip unit and to transmit the trip signal to the trip unit by a movement of the repulsive plate when a power is applied to the Thomson coil,
• wherein the Thomson drive is provided at the trip unit, and
• wherein the trip unit comprises:
• a trip latch disposed to be rotatable between a restricting position where one of the links is restricted from being rotated to the closing position by contacting the one of the plurality of links that rotate the main shaft to the closing position, and a releasing position where the one of the links is allowed to rotate to the closing position;
• and
• a trip lever disposed at one side of the trip latch and configured to restrict the trip latch from rotating to the releasing position or configured to release the restriction, and wherein the Thomson drive comprises a signal transmission actuator,
• wherein the signal transmission actuator comprises:
• a Thomson coil disposed at one side of the trip lever;
• and
• a repulsive plate disposed at one side of the Thomson coil and configured to move the trip lever to the releasing position when a power is applied to the Thomson coil.