A three phase surge protection device is disclosed. In an embodiment a device include a stack comprising a first varistor, a second varistor and a third varistor, wherein the varistors are electrically connected to form a circuit and a first thermal disconnect configured to interrupt the circuit when a temperature of the first thermal disconnect exceeds a predefined temperature.

An arc-preventing fast-breaking surge protection device is disclosed. In one of implement, surge protection device includes an arc-preventing assembly consisted of an arc-preventing catapult and an elastic element, comprising a voltage sensitive assembly, a response switch assembly, a thermosensitive element, an inner shell and an outer cover. The voltage sensitive assembly is tightly coupled with the response switch assembly. When the instantaneous surge voltage in circuits causes the voltage sensitive assembly to continuously heat up due to the fault short-circuit current, the response switch assembly causes the arc-prevent assembly to be catapulted and separated by the thermal coupling response of the thermosensitive element, meanwhile the response switch assembly is conceal by the arc-preventing assembly, thus preventing the arc generated when the switch is s catapulted and separated from forming a short-circuit and an overload, thus effectively avoiding fire and explosion hazards and further preventing secondary damage of electronic devices.

An example interruption switch includes a casing surrounding a contact unit, defining a current path through the switch, which has two connection contacts, a separation region and a sabot. A current supplied to the contact unit may be interrupted via the one of the connection contacts and discharged via the other connection contact. At least one chamber in the switch, delimited by the separation region, is substantially filled with a vaporizable medium in contact with the separation region. The separation region is separable into at least two parts through the supplied current when a threshold amperage is exceeded. An electric arc forming between the two parts at least partially vaporizes the vaporizable medium, and a gas pressure to which the sabot is exposed forms. The sabot moves, in the casing, from a starting to an end position, achieving an insulation spacing between the connection contacts.

A method of making printed circuit board vias using a double drilling and plating method is disclosed. A first hole is drilled in a core, the first hole having a first diameter. The first hole is filled and/or plated with an electrically conductive material. A circuit pattern may be formed on one or two conductive layers of the core. A multilayer structure may then be formed including a plurality of cores that also include pre-drilled and plated via holes, wherein at least some of the pre-drilled and plated via holes are aligned with the first hole. A second hole is then drilled within the first hole and the aligned pre-drilled and plated holes, the second hole having a second diameter where the second diameter is smaller than the first diameter. A conductive material is then plated to an inner surface of the second hole.

A circuit protection device includes: a housing (102) defining a cavity (130); a metal oxide varistor (110) disposed within the cavity; a movable electrode (122) attached to a first side of the metal oxide varistor by a solder connection (140); an arc shield (114) disposed within the housing on the first side of the metal oxide varistor and adjacent to the movable electrode; and a spring (120) attached to the arc shield, wherein the arc shield is mechanically biased against the movable electrode along a surface direction parallel to the first side when the spring is in a compressed state. The device is easy to assemble in lower cost and provides fast response to overheating caused by a fault condition.

A method of making printed circuit board vias using a double drilling and plating method is disclosed. A first hole is drilled in a core, the first hole having a first diameter. The first hole is filled and/or plated with an electrically conductive material. A circuit pattern may be formed on one or two conductive layers of the core. A multilayer structure may then be formed including a plurality of cores that also include pre-drilled and plated via holes, wherein at least some of the pre-drilled and plated via holes are aligned with the first hole. A second hole is then drilled within the first hole and the aligned pre-drilled and plated holes, the second hole having a second diameter where the second diameter is smaller than the first diameter. A conductive material is then plated to an inner surface of the second hole.

A surge protective device (SPD) includes a first electrical terminal, a second electrical terminal, and an overvoltage protection circuit connected between the first and second electrical terminals. The overvoltage protection circuit includes a gas discharge tube and a current management circuit connected in series to the gas discharge tube. The current management circuit includes a varistor and a resistor that are connected in parallel between a first node of the current management circuit and a second node of the current management circuit.

This device consists of a housing (1) made of electrically insulating material, in which a fuse (6) is provided with at least one main fuse wire (7) located in its cavity. The main fuse wire (7) is electrically conductively connected at one end to at least one connecting pin (2) which is led out of the housing (1) and at the other end it is electrically conductively connected to at least one terminal (3) located in at least one cavity (4) formed in the housing (1). The shape of the connecting pin (2) is adapted for connection to the protected device.

A method of making printed circuit board vias using a double drilling and plating method is disclosed. A first hole is drilled in a core, the first hole having a first diameter. The first hole is filled and/or plated with an electrically conductive material. A circuit pattern may be formed on one or two conductive layers of the core. A multilayer structure may then be formed including a plurality of cores that also include pre-drilled and plated via holes, wherein at least some of the pre-drilled and plated via holes are aligned with the first hole. A second hole is then drilled within the first hole and the aligned pre-drilled and plated holes, the second hole having a second diameter where the second diameter is smaller than the first diameter. A conductive material is then plated to an inner surface of the second hole.

An arc-preventing fast-breaking surge protection device is disclosed. In one of implement, surge protection device includes an arc-preventing assembly consisted of an arc-preventing catapult and an elastic element, comprising a voltage sensitive assembly, a response switch assembly, a thermosensitive element, an inner shell and an outer cover. The voltage sensitive assembly is tightly coupled with the response switch assembly. When the instantaneous surge voltage in circuits causes the voltage sensitive assembly to continuously heat up due to the fault short-circuit current, the response switch assembly causes the arc-prevent assembly to be catapulted and separated by the thermal coupling response of the thermosensitive element, meanwhile the response switch assembly is conceal by the arc-preventing assembly, thus preventing the arc generated when the switch is s catapulted and separated from forming a short-circuit and an overload, thus effectively avoiding fire and explosion hazards and further preventing secondary damage of electronic devices.