A variable inductor comprises a primary conductor, a first secondary conductor and one or more switch. The primary conductor has a first node and a second node, wherein the first node is used to connect a first external component and the second node is used to connect a second external component. The first secondary conductor magnetically couples to the primary conductor. The one or more switch has two sides connected to the first secondary conductor, respectively. The first secondary conductor is formed a single-loop structure with two or more changeable current paths which are operated by the states of the one or more switch. An integrated circuit using the variable inductor is also introduced.

Some features pertain to a package substrate that includes at least one dielectric layer, an inductor in the at least one dielectric layer, a first terminal coupled to the inductor, a second terminal coupled to the inductor, and a third terminal coupled to the inductor. The first terminal is configured to be a first port for the inductor. The second terminal is configured to be a second port for the inductor. The third terminal is a dummy terminal. In some implementations, the package substrate includes a solder resist layer over the dielectric layer, where the solder resist layer covers the third terminal. In some implementations, the package substrate includes a solder interconnect over the third terminal, such that the solder resist layer is between the third terminal and the solder interconnect. In some implementations, the package substrate is coupled to a die comprising a plurality of switches.

There is provided a diagnosing device for an on-load tap changing apparatus of a transformer, which can diagnose the degradation degree of insulating oil at high accuracy by a relatively simple device configuration. A diagnosing device for an on-load tap changing apparatus has an insulating oil tank in which insulating oil is sealed, a changeover switching device that is disposed within the insulating oil tank and performs the tap changing operation of a tap winding, a tap selector that selects the tap position of the tap winding, and a polarity (transposition) changer that inverts the polarity of the tap winding or a winding connected to the tap winding. The diagnosing device includes an arc discharge light detector that detects arc discharge light that is emitted at changing the tap position of the tap selector. The degradation degree of the insulating oil is diagnosed based on the arc discharge light detected by the arc discharge light detector.

The regulation, power-handling capability, and reliability of a transformer is improved by a connected switching network which changes the effective numbers of turns and effective wire size of the windings synchronously during each cycle of an applied AC input voltage.

Embodiments of the disclosure pertain to a voltage regulator system having a voltage regulation controller and a transformer assembly. The transformer assembly includes a coil winding, a multi-contact tap arrangement connected to the coil winding, and a multifurcated tap changer system that includes a first tap changer having a contactor element which makes contact with a first contact of the multi-contact tap arrangement when the controller provides a positioning stimulus based on sensing a voltage deviation from a nominal output voltage of the voltage regulator system. The multifurcated tap changer system further includes a second tap changer that is mechanically ganged to the first tap changer and includes another contactor element arranged to automatically make contact with a second contact of the multi-contact tap arrangement when the contactor element of the first tap changer makes contact with the first contact of the multi-contact tap arrangement.

An inductor device includes at least two wires and at least two switches. Each of the at least two wires includes an opening, and the openings are disposed correspondingly to each other. One of the at least two switches is coupled to two terminals of the opening of one of the at least two wires. Another one of the at least two switches is coupled to one terminal of the opening of the one of the at least two wires and one terminal of the opening of another one of the at least two wires in an interlaced manner. If the one of the at least two switches is turned on, one of the at least two wires forms an inductor; if another one of the at least two switches is turned on, both of the at least two wires form the inductor.

A power system can include a first tap changer for a first regulated transformer, where the first tap changer has a plurality of first positions. The power system can also include a second tap changer for a second regulated transformer, where the second tap changer has a plurality of second positions. The power system can further include at least one first instrument transformer coupled to the first regulated transformer. The power system can also include at least one second instrument transformer coupled to the second regulated transformer. The power system can further include a controller coupled to the at least one first instrument transformer and the at least one second instrument transformer, where the controller adjusts the first tap changer to a first adjusted position among the first positions based on the first measurements of the first regulated transformer and the second measurements of the second regulated transformer.

Electronic systems for controlling submersible pumps are provided herein. In certain configurations, a pump system includes three or more submersible pumps used for pumping fluid from a reservoir, sensors used for generating sense signals indicating a fluid level of the reservoir, and a control circuit for selectively activating the pumps based on the sense signals so as to control pumping of fluids from the reservoir. In certain implementations, the control circuit is operable in a plurality of user-selectable operating modes associated with different pump activation sequences in response to the fluid level of the reservoir rising.

A transformer arrangement includes a transformer, a transformer tank and at least one tap changer that is arranged to be connected to said transformer. The transformer arrangement further includes at least one support structure which is arranged to be connected to the tap changer and to extend between the tap changer and at least two support members located between the tap changer and at least two points on an inner surface of the transformer tank. The at least one support structure is arranged to reduce pendular movement of the tap changer.

The invention relates to an on-load tap changer (2) according to the reactor switching principle for uninterrupted load switching between different tap windings of a tapped transformer (1), comprising: an inductor (3) which is designed as an inductive transition reactance; the inductor (3) being part of the on-load tap changer (2).