The present invention aims to achieve a Pb-free protection element by using a layered body including a high melting point metal layer and a low melting point metal layer. A protection element includes an insulating substrate, a heating body, an insulating member, two electrodes, a heating body extraction electrode, and a fusible conductor. Furthermore, the fusible conductor includes a layered body including at least a high melting point metal layer and a low melting point metal layer, and the low melting point metal layer is melted by a heat generated by the heating body, whereby, while eroding the high melting point metal layer, the low melting point metal layer is drawn close to the side of the two electrodes and the heating body extraction electrode, and fused, the two electrodes and the heating body extraction electrode each having high wettability for the low melting point metal layer.

The invention relates to a safety device (1) for the emergency deactivation of an electrical water heater or a heat pump, wherein the safety device (1) comprises at least one contact pair (70, 80, 90) having at least one first contact assembly (71, 81, 91) and at least one second contact assembly (72, 82, 92), which are designed to direct the current to supply the water heater or the heat pump in a contacted state, and to interrupt the current supply to the water heater or the heat pump in an open state, as well as comprising a retaining device (94) for retaining the second contact assembly (72, 82, 92) on a tension rod (40), wherein the tension rod (40) is designed to release the retaining device (94) and the second contact assembly (72, 82, 92) from the first contact assembly (71, 81, 91) in order to interrupt a current supply to the water heater or the heat pump. The safety device (1) also comprises a housing (10) having a cover (20) and a base element (30), wherein the base element (30) has guide elements (34) and positioning elements (32) for the cover (20), which cooperate with corresponding counter guide elements (22) and counter positioning elements (20d) of the cover (20).

A device for sensing the electrical conductivity of a liquid, particularly that of the washing bath in a washing machine, including an electrically insulating supporting casing through which first and second electrodes intended to contact the washing bath extend to the outside, electrical power supply and signal acquisition and processing circuit devices housed at least in part in the supporting casing and coupled to the electrodes, and signal coupling and galvanic isolation devices, interposed between these circuit devices and the electrodes and also housed in the casing, and including at least a first and a second capacitor, each of which is interconnected in series between one of the electrodes and a corresponding terminal of the circuit.

In a protective circuit substrate having a circuit substrate and a protective element, the protective element including: an insulating substrate; a heat-generating element; first and second electrodes laminated on the insulating substrate; a first and second connecting terminals provided on one side edge of a mounting surface to be mounted to the circuit substrate, the first connecting terminals being continuous with the first and second electrodes; a heat-generating element extracting electrode provided in a current path between the first and second electrodes and electrically connected to the heat-generating element; and a meltable conductor provided between the first and second electrodes, wherein the circuit substrate includes a region for mounting the protective element in which no electrode pattern other than a connecting electrode to the protective element is provided.

To achieve a Pb-free protection element, a layered body including a high melting point metal layer and a low melting point metal layer is provided. The protection element includes an insulating substrate, a heating body, an insulating member, two electrodes, a heating body extraction electrode, and a fusible conductor. Furthermore, the fusible conductor includes a layered body including at least a high melting point metal layer and a low melting point metal layer, and the low melting point metal layer is melted by a heat generated by the heating body. While eroding the high melting point metal layer, the low melting point metal layer is drawn close to the side of the two electrodes and the heating body extraction electrode, and fused, the two electrodes and the heating body extraction electrode each having high wettability for the low melting point metal layer.

A printed circuit board (PCB) assembly according to one embodiment of the present disclosure includes a first pad; a second pad disposed to be spaced apart from the first pad; and a thermal fuse provided with a first terminal and a second terminal which are each coupled to the first pad and the second pad by soldering. Here, a contact area between the first pad and the first terminal is smaller than that between the second pad and the second terminal.

A device for sensing the electrical conductivity of a liquid, particularly that of the washing bath in a washing machine, including an electrically insulating supporting casing through which first and second electrodes intended to contact the washing bath extend to the outside, electrical power supply and signal acquisition and processing circuit devices housed at least in part in the supporting casing and coupled to the electrodes, and signal coupling and galvanic isolation devices, interposed between these circuit devices and the electrodes and also housed in the casing, and including at least a first and a second capacitor, each of which is interconnected in series between one of the electrodes and a corresponding terminal of the circuit.

Disclosed is a fuse resistor provided on an electrical circuit to protect the electrical circuit and elements. The fuse resistor includes a substrate on which first and second resistive terminals and fuse terminals are formed, first and second resistive elements surface-mounted on the first and second resistive terminals and dividing applied current or voltage, and a temperature fuse surface-mounted on the fuse terminals and broken by heat generated from the first and second resistive elements. If overcurrent or overvoltage is applied, the first and second resistive elements generate heat and the temperature fuse is broken by the generated heat.

Described is a fuse for an electrical circuit, comprising two contact arms, each having at least one connecting pin for inserting into a hole of a printed circuit board, and a spring which connects the two contact arms in an electrically conductive manner. According to this disclosure, it is provided that the spring is fastened to at least one of the two contact arms by means of a fastening means that loses its strength at a trigger temperature of the fuse, wherein the fuse is formed in such a manner that by inserting the connecting pins into holes of a printed circuit board, the spring is loaded such that the spring lifts from the at least one contact arm by spring force as soon as the fastening means loses its strength due to overheating. Moreover, a printed circuit board comprising such a fuse is described.