An electric operating device for a circuit breaker that includes a housing, a transmission mechanism is installed in the housing, and a side wall of the housing serves as an operation surface and is provided with a first sliding groove communicated with the interior of the housing; a sliding rod is installed in the housing; a driving member controlled by the transmission mechanism is installed on the sliding rod; the driving member is provided with a closing operation portion and an opening operation portion; the driving member passes through the first sliding groove and extends out of the housing; the driving member moves along the sliding rod under the control of the transmission mechanism; and the closing operation portion and the opening operation portion operate a handle of the circuit breaker to be closed and opened respectively.

A device for switching a handle of an electrical switch has at least a first actuator and a second actuator. When the device is installed on the electrical switch, the first actuator can move the handle in a first direction and the second actuator can move the handle in a second direction opposite the first direction. The first actuator and the second actuator are shape-memory alloy actuators.

A power tool includes a housing, an electric motor, a switch, an operating element, a contact rod, a pressing block, and a reset element. The electric motor is disposed in the housing. The switch includes a trigger point for controlling the electric motor to be turned on. The operating element is operated so that the switch is triggered. The contact rod is supported by the housing, where the operating element is capable of pushing the contact rod to move. The pressing block is elastically connected to the contact rod and capable of being driven by the contact rod to push the trigger point. The reset element is connected to the contact rod.