Disclosed in the present invention is a novel overvoltage protective device for lightning protection, comprising a first varistor, a second varistor, a PTC Thermistor, and lead-out terminals. The first varistor and the PTC Thermistor are connected in parallel, and then further connected in series with the second varistor to form a single port combined circuit. The surge-withstand capability of the first varistor is higher than the surge-withstand capability of the second varistor. At least one of the two lead-out terminals of the single port combined circuit is a thermally-conductive end with low thermal resistance. The second varistor is thermally coupled to the PTC Thermistor. The thermally-conductive end with low thermal resistance is thermally coupled to one or both of the second varistor and the PTC Thermistor.

A power supply device is disclosed. A circuit board is disposed inside a conductive housing. A rectifying module is disposed on the circuit board and has primary and secondary sides. The grounding module includes a first grounding element, a second grounding element, and a fastening element. Two terminals of the first surge protection module are respectively electrically connected to the primary side and the first grounding element. Two terminals of the second surge protection module are respectively electrically connected to the secondary side and the second grounding element. The second grounding element and the first grounding element are not directly connected. The fastening element passes through the conductive housing, the circuit board, the first grounding element, and the second grounding element so that the conductive housing, the first grounding element, and the second grounding element are electrically connected to one another.

A power supply device is disclosed. A circuit board is disposed inside a conductive housing. A rectifying module is disposed on the circuit board and has primary and secondary sides. The grounding module includes a first grounding element, a second grounding element, and a fastening element. Two terminals of the first surge protection module are respectively electrically connected to the primary side and the first grounding element. Two terminals of the second surge protection module are respectively electrically connected to the secondary side and the second grounding element. The second grounding element and the first grounding element are not directly connected. The fastening element passes through the conductive housing, the circuit board, the first grounding element, and the second grounding element so that the conductive housing, the first grounding element, and the second grounding element are electrically connected to one another.

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.

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.

To protect a connected electrical load from anomalous electricity, an apparatus has a condition sensing unit configured to distinguish a power event type from among power event types from characteristics of an input electricity waveform accepted through an input port. The condition sensing unit indicates the power event type when a corresponding overvoltage criterion is met by characteristics of the input electricity waveform. A power control unit generates, responsive to a power event, a modulation signal that defines at least one amplitude notch in the input electricity waveform in accordance with the power event type. A switching mechanism electrically interposed between the input port and the output port transitions into conducting and non-conducting states in accordance with the modulation signal to superimpose the notch on the input electricity waveform.

To protect a connected electrical load from anomalous electricity, an apparatus has a condition sensing unit configured to distinguish a power event type from among power event types from characteristics of an input electricity waveform accepted through an input port. The condition sensing unit indicates the power event type when a corresponding overvoltage criterion is met by characteristics of the input electricity waveform. A power control unit generates, responsive to a power event, a modulation signal that defines at least one amplitude notch in the input electricity waveform in accordance with the power event type. A switching mechanism electrically interposed between the input port and the output port transitions into conducting and non-conducting states in accordance with the modulation signal to superimpose the notch on the input electricity waveform.

Circuits, methods, and apparatus that may provide power supply voltages in a safe and reliable manner that meets safety and regulatory concerns and does not exceed physical limitations of cables and other circuits and components used to provide the power supply voltages. One example may provide a cable having a sufficient number of conductors to provide power without exceeding a maximum current density for the conductors. Another example may provide a cable having more than the sufficient number of conductors in order to provide an amount of redundancy. Current sense circuits may be included for one or more conductors. When an excess current is sensed, a power source in the power supply may be shut down, the power source may be disconnected from one or more conductors, or both events may occur.

A surge protector having a hot line, a load line, a neutral line, and a ground line, the surge protector is provided. The surge protector has a fuse coupled between the hot line and the load line to protect loads from current surges. A differential mode protection circuit is coupled between the load line and the neutral line to protect loads from differential mode transient voltage surges. A common mode protection circuit is coupled to the load line, the neutral line and the ground line to protect loads from common mode transient voltage surges. An indicator circuit monitors the differential mode protection circuit and the common mode protection circuit to provide an indication as to the operational status of the surge protector.

Provided is a sensor device wherein malfunction due to a negative surge is suppressed. This sensor device is provided with: a sensor element wherein electrical characteristics change corresponding to physical quantities; a signal processing circuit that processes output signals of the sensor element; a first transistor element that supplies currents to the sensor element and the signal processing circuit; a control circuit that controls a base current of the first transistor element; a power supply terminal; and a ground terminal. The sensor device is characterized in that the control circuit is provided with a limiting section that limits a current flowing from the ground terminal toward a base terminal of the first transistor element.