Abstract: A titterboard type switch with security structure, wherein a relay unit is disposed between two terminal legs connected with power wires and an electrothermal conductor is connected between the relay unit and one of the terminal legs, whereby when powered on, the electrothermal conductor is slightly heated and in the case of overload, the electrothermal conductor creates high temperature. The relay unit is disposed with a resilient movable contact pushable by a sliding member for controlling whether the movable contact contacts with the other terminal leg or not. The sliding plate is pushed by a swinging plate which is shifted by a push button via a linking unit.

Abstract: A plug with security device, including a housing, several conductive insertion plates adapted to be inserted into a power socket, conductive wires connected to an electric appliance and a security device. The insertion plates are connected with the conductive wires in the housing. The security device is disposed between at least one insertion plate and one conductive wire and includes a casing, a disconnector seat disposed therein, a thermal bimetal blade disposed on the disconnector seat, a movable contact disposed on the bimetal blade, a fixed contact disposed in the casing and connected with the conductive wire to naturally contact with the movable contact, and an insulative separating structure. When an excessively large current passes through the electric appliance, the bimetal plate is bent to separate the movable contact from the fixed contact and open the circuit.