The present disclosure is directed to systems and methods for operating a three-way switch. The system includes a user input. The system further includes a relay electrically coupled to a first traveler wire, a second traveler wire, and a LINE conductor, wherein the relay has a first position and a second position. The relay may be initially set to the first position. The system further includes a toroid having an aperture, wherein a sensing conductor passes through the aperture to generate a sensing voltage. The system further includes a controller configured to toggle the relay from the first position to the second position when (1) the user input is in the on-setting and he sensing voltage is less than a threshold value or (2) the user input is in the off-setting and the sensing voltage is greater than the threshold value.

The present disclosure is directed to systems and methods for operating a three-way switch. The system includes a user input. The system further includes a relay electrically coupled to a first traveler wire, a second traveler wire, and a LINE conductor, wherein the relay has a first position and a second position. The relay may be initially set to the first position. The system further includes a toroid having an aperture, wherein a sensing conductor passes through the aperture to generate a sensing voltage. The system further includes a controller configured to toggle the relay from the first position to the second position when (1) the user input is in the on-setting and he sensing voltage is less than a threshold value or (2) the user input is in the off-setting and the sensing voltage is greater than the threshold value.

A device includes an armature, a coil, and a circuit. The armature is configured to move between a close position that electrically couples the armature to a contact and an open position that is not electrically coupled to the contact. The coil is configured to release a voltage configured to de-magnetize the coil, thereby causing the armature to move from the close position to the open position. The circuit is configured to provide reverse driving current to the coil during a period of time when the armature moves from the close position to the open position.

A device includes an armature, a coil, and a circuit. The armature is configured to move between a close position that electrically couples the armature to a contact and an open position that is not electrically coupled to the contact. The coil is configured to release a voltage configured to de-magnetize the coil, thereby causing the armature to move from the close position to the open position. The circuit is configured to provide reverse driving current to the coil during a period of time when the armature moves from the close position to the open position.

A number of low voltage vacuum tube circuits include using supply voltages well below the manufacturer's recommended voltages applied to the plate or screen grid. Some of the tube circuits operate at near zero plate and or screen grid voltages. Other low voltage circuits have forward biasing on one or more grids that are normally biased at a non positive voltage or a grid that is normally connected a cathode. Substantially lower supply voltages allow for example, the filament supply to also supply voltage to the plate and or grid for providing an output signal at a grid and or a plate.

A number of low voltage vacuum tube circuits include using supply voltages well below the manufacturer's recommended voltages applied to the plate or screen grid. Some of the tube circuits operate at near zero plate and or screen grid voltages. Other low voltage circuits have forward biasing on one or more grids that are normally biased at a non positive voltage or a grid that is normally connected a cathode. Substantially lower supply voltages allow for example, the filament supply to also supply voltage to the plate and or grid for providing an output signal at a grid and or a plate.

A system includes a contactor operatively connected to a coil for actuating the contactor to open and close a circuit. A pass element includes a source, a drain, and a gate, wherein the drain is electrically connected to the coil, and wherein the coil is in series between the pass element and ground. A voltage source is connected to the source of the pass element to pass current into the coil when the pass element is in a pass state. A current source control circuit with economizer is operatively connected to the gate of the pass element. A delay circuit is operatively connected to the current source control circuit with economizer and to a command line to command a lower current for holding the contactor closed after a delay has expired for the contactor to transition.

A system includes a contactor operatively connected to a coil for actuating the contactor to open and close a circuit. A pass element includes a source, a drain, and a gate, wherein the drain is electrically connected to the coil, and wherein the coil is in series between the pass element and ground. A voltage source is connected to the source of the pass element to pass current into the coil when the pass element is in a pass state. A current source control circuit with economizer is operatively connected to the gate of the pass element. A delay circuit is operatively connected to the current source control circuit with economizer and to a command line to command a lower current for holding the contactor closed after a delay has expired for the contactor to transition.

A switch system includes a system main relay, a temperature measuring unit, and a controller. The system main relay is configured to electrically connect a battery and an onboard device to each other by turning on a contact point, and to electrically disconnect the battery and the onboard device by turning off the contact point. The temperature measuring unit is configured to measure temperature of the contact point of the system main relay. The controller is configured to cause the system main relay to repeatedly turn on and off the contact point at a predetermined timing, (i) when the temperature of the contact point of the system main relay is a predetermined temperature or more or (ii) when an amount of rise in the temperature of the contact point is a predetermined amount or more.

A method for determining the operating status of a MV switching device (1), which comprises one or more electric poles, each comprising a movable contact and a fixed, contact adapted to be coupled or uncoupled during the switching operations of said switching device, and an electromagnetic actuator comprising a magnetic core, a test coil wound around said magnetic core and a movable plunger operatively coupled to the movable contact of each electric pole. The method comprises: providing a test signal (ST) to said test coil for an observation period of time (T.sub.O), said test signal having a waveform adapted to excite said magnetic core; obtaining measuring data (V.sub.M, I.sub.M) indicative of the voltage at the terminals of said test coil and of the current circulating along said test coil during said observation period of time; calculating observation data (R.sub.N, I.sub.M) indicative of the electric behaviour of said test coil at the end of said observation period of time on the base of said measuring data; selecting at least a transformation function (F.sub.1, F.sub.2) indicative of the electromagnetic behaviour of said electromagnetic actuator; and calculating first estimation data (P, T) indicative of the operating status of said electromagnetic actuator on the base of said observation data (R.sub.N, L.sub.N) by using said transformation function, said first estimation data comprising, a first estimation value (P) indicative of the position of the movable plunger of said electromagnetic actuator.