Abstract: A method of protecting a load circuit includes sensing a load current passing through a switch electrically in series with the load circuit, sensing a voltage drop across the switch, determining a rate of change of the voltage drop across the switch, determining whether to deactivate the switch based on the load current and the rate of change of the voltage drop across the switch, in response to determining to deactivate the switch, deactivating the switch to shut off current to the load circuit.

Abstract: An electromechanical switching protection system includes an electromechanical switchgear having contacts configured to selectively open and close in response to a control signal, and a junction field effect transistor (JFET) device electrically connected in series with the electromechanical switchgear between an input terminal and an output terminal of the electromechanical switching protection system, a gate of the JFET device being electrically connected to the output terminal.

Abstract: A contactor includes a first actuator, a compressive element moveably coupling the first actuator to a rigid portion of the contactor, a shaft configured to move toward the rigid portion when the contactor is in an energized state and to move away from the rigid portion when the contactor is in a de-energized state, a second actuator fixedly coupled to the shaft, and a common contact extending between the first actuator and the second actuator, the common contact being moveable with respect to a first contact, wherein the compressive element is configured to press the first actuator against the common contact, and wherein the first actuator is configured to electrically connect the common contact and the first contact when the contactor is in the de-energized state, and the second actuator is configured to electrically disconnect the common contact and the first contact when the contactor is in the energized state.

Abstract: There is provided a protection circuit configured to indicate an overcurrent condition of a conductor conducting a load current, the protection circuit including a first current integrator and a second current integrator, each of the first and second integrators being configured to integrate an input voltage proportional to the load current, a summing amplifier configured to receive an offset voltage, to amplify a signal from the second integrator, and to generate a trip threshold based on the input voltage and the offset voltage, and a comparator configured to compare an output of the first current integrator and the trip threshold, and to generate a trip signal at a trip time when the trip threshold is equal to an output of the first integrator, the trip signal indicating an overcurrent condition.

Abstract: Systems and methods for balancing multi-cell batteries are provided. In one embodiment, the battery balancing circuit includes a battery including a plurality of cells coupled in series, a first terminal and a second terminal, a transformer including a primary winding and a plurality of secondary windings, where each secondary winding is coupled to one of the plurality of cells via a secondary switch and a rectifier circuit, where the primary winding is coupled between the first terminal and the second terminal of the battery, a primary switch in series with the primary winding of the transformer, and a control circuitry coupled to the primary switch, the plurality of secondary switches, and each of the plurality of cells.

Abstract: A system and method for emulating an ideal diode for use in a power control device is provided. In one embodiment, the invention relates to a circuit for emulating an ideal diode, the circuit including at least one field effect transistor including a source, a drain, a gate, and a body diode, an input; an output coupled to the drain, a control circuit including a current sensor coupled between the input and the source, and a control circuit output coupled to the gate, wherein the control circuit is configured to activate the at least one field effect transistor based on whether the current flowing into the source is greater than a predetermined threshold, and wherein the body diode comprises an anode coupled to the source and a cathode coupled to the drain.

Abstract: Solid state power controllers are described that include a switch controlled by a microcontroller and communication contacts. In one aspect of the invention, the microcontroller is galvanically isolated from the communication contacts using magnetoresistive isolation. In another aspect of the invention a number of solid state power controllers are connected to an external microcontroller to form a power distribution array. In addition, messages exchanged between the external microcontroller and the solid state power controllers can be used to configure the solid state power controllers and provide a user interface.

Abstract: Solid state power controllers in various configurations are provided. One such solid state power controller includes a power connector, a load connector and at least one communication connector, a solid state switch electrically connectable between the power connector and the load connector, where the switch includes an input, a microcontroller coupled to the input of the solid state switch, and current sensing circuitry coupled to the microcontroller and configured to sense a current flowing through the solid state switch, the current sensing circuitry including an amplifier having an offset error, where the current sensing circuitry is configured to generate a signal indicative of the current flowing through the solid state switch, and bias the generated signal to a predetermined level to substantially eliminate the offset error in the amplifier.

Abstract: A system and method for quickly discharging a DC relay is provided. In one embodiment, the invention relates to circuit for discharging a relay coil, the circuit including a first suppression circuit coupled across a control power source, a switch, a relay coil in series with the switch, wherein the relay coil and the switch are coupled across the control power source, and a second suppression circuit coupled across the relay coil, wherein the relay coil is configured to actuate at least one load switch when sufficiently energized by the control power source, wherein the first suppression circuit is configured to discharge energy stored in the relay coil, and wherein the second suppression circuit is configured to discharge energy stored in the relay coil.

Abstract: A system and method for quickly discharging an AC relay is provided. In one embodiment, the invention relates to a circuit for discharging a relay coil a relay, the circuit including relay circuitry having a relay coil disposed across a rectifier circuit, wherein the relay coil is configured to actuate at least one load switch when sufficiently energized, relay release circuitry including suppression circuitry coupled across the relay coil, and isolation circuitry in series between the relay coil and the rectifier circuit, and control circuitry configured to provide a voltage to the rectifier circuit to energize the relay coil, wherein the isolation circuitry is configured to isolate the relay coil and suppression circuitry based on a signal from the control circuitry.

Abstract: A system for precisely controlling the operational characteristics of a relay is provided. In one embodiment, the invention relates to a relay having performance characteristics that vary with a temperature of the relay, where the relay comprises a plurality of operational phases including a switching phase and a holding phase, and a relay control circuit configured to provide a preselected current to the relay at least during the switching phase and the holding phase, where the preselected current remains substantially constant despite a change in the temperature of the relay, where the relay is configured to transition from a non-energized position to an energized position during the switching phase, and where the relay is configured to maintain the energized position during the holding phase.

Abstract: A system and method for protecting a coil structure in a controlled switch.

Abstract: The present invention relates to a power control system with a fusible link. In one embodiment, the invention relates to a power control system, having a device possessing an output, a fusible link connected to the output of the device, a heating element controller, and at least one heating element connected to the heating element controller, where the heating element controller is configured to control the flow of current through the heating element, where the heating element controller is configured to monitor activity of the device, and where the heating element is configured to generate sufficient heat to fuse the fusible link within a predetermined time period when current flows through the heating element.

Abstract: Solid state power controllers are described that include a switch controlled by a microcontroller and communication contacts. In one aspect of the invention, the microcontroller is galvanically isolated from the communication contacts using magnetoresistive isolation. In another aspect of the invention a number of solid state power controllers are connected to an external microcontroller to form a power distribution array. In addition, messages exchanged between the external microcontroller and the solid state power controllers can be used to configure the solid state power controllers and provide a user interface.

Abstract: A non-volatile status indicator switch is provided. In one embodiment, the invention relates to an aircraft electrical system including a fault detection circuit coupled to a relay, and a fault indicator circuit coupled to the fault detection circuit and to a control input of the relay, wherein the fault indicator circuit includes a nonvolatile memory element, wherein the fault detection circuit is configured to detect a fault and to provide a signal indicative of the fault to the fault indicator circuit, and wherein the fault indicator circuit is configured to respond to the signal indicative of the fault by providing a predetermined control signal to the relay and by storing information indicative of the detection of the fault in the nonvolatile memory element.

Abstract: Apparatus and methods for detecting high level arc faults in aircraft power systems are disclosed. One embodiment of the invention with reduced susceptibility to nuisance trips includes three low pass filters each having an output connected to a threshold detector. In addition, a three input comparator is connected to an output of each of the threshold detectors and a fault verification circuit is connected to an output of the three input comparator. An embodiment of the method of the invention for detecting arc faults in three phase aircraft power systems involves detecting at least one of the three phases having a current exceeding a predetermined threshold, detecting differences between the three phases and generating a signal indicative of difference being detected between the three phases for a time period exceeding a predetermined duration.