Patent ID: 7446643

Claim:
An electrical protection system, which can be connected between an electrical power supply and an electrical load, comprising, a single switch switchable between a normal state in which the switch is electrically connected in series between the power supply and the load such that an operating current passes through the switch and the load, and a fault state in which the switch is electrically disconnected with the load at a single discontinuity such that no current passes through the load, wherein the switch switches to the fault state in an over-current or an over-temperature situation; and a controller operable in an open state when the switch operates in the normal state, in which state the controller is electrically disconnected from the power supply such that no current passes through the controller, or a closed state when the switch operates in the fault state, in which state the controller is electrically connected in series between the switch and the power supply such that a self-holding current passes through the switch and the controller, wherein the controller operates to automatically set the switch to the normal state when the self-holding current is off; wherein the switch is a bimetal switch; and the controller includes a first PTC controller thermally coupled with the switch and the first PTC device is heated up under the self-holding current for keeping the switch in connection with the first PTC device.