A transformer arrangement includes a transformer having a winding and a surge arrester arrangement connected thereto. The SAA includes a surge arrester (SA) connected across at least a section of the winding and a switch operable between a closed and open state. In the closed state, SA is electrically connected across at least the section, and in the open state, the SA electrically disconnected from at least the section. The SAA includes at least one further SA .sub.arranged to be connected across at least one further section and at least one further switch, operable between a closed and open state, wherein in the closed state the further SA is electrically connected across the at least one further section, and in the open state, the at least one further SA is electrically disconnected from the further section. A method for electrically connecting/disconnecting the transformer to/from the SAA—is also described.

A transformer arrangement includes a transformer having a winding and a surge arrester arrangement connected thereto. The SAA includes a surge arrester (SA) connected across at least a section of the winding and a switch operable between a closed and open state. In the closed state, SA is electrically connected across at least the section, and in the open state, the SA electrically disconnected from at least the section. The SAA includes at least one further SA .sub.arranged to be connected across at least one further section and at least one further switch, operable between a closed and open state, wherein in the closed state the further SA is electrically connected across the at least one further section, and in the open state, the at least one further SA is electrically disconnected from the further section. A method for electrically connecting/disconnecting the transformer to/from the SAA—is also described.

According to one embodiment, an inductor includes a magnetic substance core, a coil, a cast case and a cast resin. The coil is wound around the magnetic substance core. The cast case has a body at least partially formed from conductive substance, stores the magnetic substance core and the coil. The cast resin that is formed from a first resin which is an insulator, is located within the cast case, covering the magnetic substance core and the coil.

An external switch actuator includes: a guide tube having a first end and a second end, the first end configured to be attached to a door of a compartment in substantial alignment with both a hole in the door and a switch actuator within the compartment, and the second end configured to be disposed within an interior of the compartment and separated from the switch actuator by a gap when the door is closed; a coupling shaft configured to be operably placed within the guide tube, the coupling shaft having an electrical insulator disposed between an actuator side adapter and a switch side adapter, and a length equal to or greater than a distance between the switch actuator and the hole in the door when the door is closed.

A low pass filter includes a first input/output terminal, a second input/output terminal, a signal line, inductors connected in the signal line, and capacitors connected between the signal line and ground. In the signal line, a capacitor is connected in parallel to the inductor that is connected closest to the first input/output terminal, and the inductor and the capacitor define a first parallel resonator.

A low pass filter includes a first input/output terminal, a second input/output terminal, a signal line, inductors connected in the signal line, and capacitors connected between the signal line and ground. In the signal line, a capacitor is connected in parallel to the inductor that is connected closest to the first input/output terminal, and the inductor and the capacitor define a first parallel resonator.

The present disclosure relates to a protective relay detecting disconnection in a circuit comprising a disconnection detection unit including a plurality of nodes connected to both ends of an output of a transformation unit, a reference voltage generation unit forming a reference voltage, and a plurality of resistors forming a voltage dividing resistor and connecting the plurality of nodes and the reference voltage generation unit; a sensing voltage generation unit applying a voltage for forming a predetermined voltage difference with respect to the reference voltage; and a disconnection determination unit connected to a first node, in which the magnitude of a voltage signal applied by the voltage dividing resistor varies depending on whether at least one of the transformation unit and the circuit connected to the transformation unit is disconnected, and detecting whether at least one of the transformation unit and the circuit connected to the transformation unit is disconnected.

The present disclosure provides a magnetic element, including: a magnetic core with at least one magnetic column extending along a first direction; a first winding surrounding the magnetic column; a second winding at least partially surrounding the first winding; and a third winding at least partially surrounding the second winding. The number of turns of the second winding is less than or equal to the number of turns of the first winding. The number of turns of the third winding is less than or equal to the number of turns of the first winding.

The present disclosure provides a magnetic element, including: a magnetic core with at least one magnetic column extending along a first direction; a first winding surrounding the magnetic column; a second winding at least partially surrounding the first winding; and a third winding at least partially surrounding the second winding. The number of turns of the second winding is less than or equal to the number of turns of the first winding. The number of turns of the third winding is less than or equal to the number of turns of the first winding.

According to one configuration, an inductor device includes a first electrically conductive path; a second electrically conductive path, the first electrically conductive path electrically isolated from the second electrically conductive path; first material, the first material operative to space the first electrically conductive path with respect to the second electrically conductive path; and second material. The second material has a substantially higher magnetic permeability than the first material. An assembly of the first electrically conductive path, the second electrically conductive path, and the first material resides in a core of the second material.