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.

The invention is related to a luminaire comprising a lighting module for emitting light, a driver for driving operation of the lighting module, a runtime overvoltage protection device for protecting the lighting module and the driver from exposure to overvoltage above a first overvoltage tripping limit, and a provisional overvoltage protection device that is connected in parallel to the runtime overvoltage protection device and has a second overvoltage tripping limit. The second tripping limit smaller than the first overvoltage tripping limit so that the provisional overvoltage protection device provides overvoltage protection to the runtime overvoltage protection device. Moreover, the provisional overvoltage protection device is deactivatable.

A data interface with overvoltage protection circuitry includes a bus interface and power rectification stage configured to provide supply and return voltages for the data interface and overvoltage protection circuitry, a first power level overvoltage protection circuit, a second power level overvoltage protection circuit, a DALI endpoint power output port, a power supply for a DALI endpoint device drawing current from the power output port, a receiver configured to receive signals on the DALI bus, and, a transmitter configured to send signals on the DALI bus.

The invention relates to a circuit arrangement for combined protection of a load from temporary and transient overvoltages with emergency operation of the load in the presence of a temporary overvoltage and with integrated follow current limitation, wherein a first surge arrester, in particular a spark gap or a varistor, is provided between network-side input terminals and a second surge arrester, in particular a varistor, is provided between load-side output terminals for follow current limitation. According to the invention, at least one controlled semiconductor switch is provided in each case in the series branch between the input terminal and the output terminal and in the output-side parallel branch, wherein a mechanical switch and a series capacitance are connected in parallel with the semiconductor switch in the series branch. Furthermore, the semiconductor switch in the parallel branch is part of a series circuit comprising a parallel circuit comprising a second surge arrester and a parallel capacitance. A series inductance is provided in the series branch between the input terminal and the parallel circuit comprising the series capacitance, the controlled semiconductor switch and the mechanical switch. A microcontroller for controlling the semiconductor switches is also present, wherein the microcontroller is connected to a current detector in the series branch.

A surge absorption circuit for a single-phase air conditioning system, including: an L line and an N line, where one end of each of the two is connected to a power source, and the other end of each is connected to one pin of a rectifier bridge; a common mode inductor, which includes a magnetic ring, and first and second common mode coils that are connected in series in the L line and the N line, respectively; a first surge absorption unit, which is connected to the side of the common mode inductor close to the power source and which comprises first and second varistors and a first discharge tube, where one end of each of the first and second varistors is connected to the L line and the N line respectively, and the other end of each is connected to each other and grounded by the first discharge tube.

Protection of an electric motor drive controller from a transient voltage is described herein. The transient voltage is provided by an alternating current (AC) power line that includes a line conductor, a neutral conductor, and a ground conductor. The transient voltage protection system includes a first stage protection device coupled to an input of a rectifier of the motor drive controller. The first stage protection device is configured to suppress the transient voltage to prevent damage to the motor drive controller. The transient voltage protection system also includes a second stage protection device coupled between the rectifier and an inverter of the motor drive controller. The second stage protection device is configured to further suppress the transient voltage to prevent damage to the inverter.

The present invention relates to a surge protection device for multi-protection mode communications, comprising: an input line into which a voltage is introduced; an output line connected to an external line; a surge discharge part provided with a ground terminal; a surge protection circuit part provided between the input line and the output line and having at least two or more surge protection circuits provided in parallel and discharging the introduced voltage to the ground terminal if the introduced voltage is a surge voltage; circuit conversion parts for selectively connecting the input line and the output line to any one of the surge protection circuits; a condition measuring part for measuring an input voltage introduced into an input terminal of the input line and a second discharge voltage from the surge protection circuit to the ground terminal and comparing each of the input voltage and the second discharge voltage with preset reference voltages; and a control circuit part for detecting abnormality of the connected surge protection circuit by using the comparison result of the input voltage and the comparison result of the second discharge voltage and converting the connected surge protection circuit into another one of the connected surge protection circuits through the circuit conversion parts if the abnormality of the connected surge protection circuit is detected. By the surge protection device for multi-protection mode communications, the damage to the surge protection circuits can be detected using the input surge voltage and no voltage is required to be additionally applied for detecting the damage to the surge protection circuits.

A TVS circuit having a first diode with a cathode coupled to a first terminal and an anode coupled to a first node. A second diode has an anode coupled to a second node and a cathode coupled to a third node. A third diode is coupled between the first node and second node. A fourth diode is coupled between the first node and third node. A fifth diode is coupled between the second node and a second terminal. A sixth diode is coupled between the second terminal and the third node. A seventh diode can be coupled between the second terminal and an intermediate node between the fifth diode and sixth diode. The first diode is disposed on a first semiconductor die, while the second diode is disposed on a second semiconductor die. Alternatively, the first diode and second diode are disposed on a single semiconductor die.

The invention relates to a method for evaluating the state and the quality of low-voltage networks, in the branched system of which there is a plurality of connected loads, by determining network measurement data by means of power quality measuring and testing devices and transferring the network measurement data, by means of a standard interface, to a control system or in retrievable form to a server. According to the invention, the overvoltage protection devices, which are or can be used in the low-voltage system and have a self-diagnosis unit and an existing wireless or wired standard interface for data transfer, are able to determine network measurement data by means of integrated or adapted power quality measuring and testing devices.

A surge protection device includes an isolating transformer configured to conduct an Ethernet data signal on a wire pair and configured to provide voltage surge protection for Ethernet equipment coupled to the wire pair, and a power supply coupled to the isolating transformer and configured to conduct a DC voltage signal from the wire pair and configured to provide voltage surge protection for the Ethernet equipment coupled to the wire pair.