A method is provided for in situ functionality testing of electrical switches using a Functional Reflectometry Test (FRT) of switches on the signal path of electrical circuits in a semiconductor interface. The method includes initiating the functionality testing of the electrical switches in situ, wherein the functionality of the electrical switches is tested while the electrical switches are connected to the Automatic Test Equipment (ATE) and are in-use testing semiconductors. The method also includes conducting full Functional Reflectometry Testing of the electrical switches in situ in an open switch state and a closed switch state to determine whether each of the electrical switches is one of fully functional, stuck closed, and stuck open, wherein testing for each state is performed as a single vector functional test to minimize test time overhead.

A control system may include a processor that may receive a first dataset associated with power properties of a rotating load device coupled to a relay device. The processor may also determine frequency properties based on the power properties and determine a switching profile to control moving a first armature of three armatures in the relay device based on the frequency properties. The switching profile is configured to control movement of the first armature between a first position and a second position, and wherein the switching profile comprises a firing angle for moving the first armature with respect to an electrical waveform, a second armature, and a third armature. The processor may then control a current provided to a relay coil of the relay device based on the switching profile, such that the relay coil causes the first armature to move.

Exemplary embodiments are disclosed of contactors with data-based preventive maintenance replacement indicators and related methods for indicating that relay contact(s) should be replaced.

Devices herein may include conductor lines connected between a power supply and load, each of the conductor lines coupled to an AC contactor and a contactor control circuit, wherein the contactor control circuit is operable to open and close one or more contactors of the AC contactor. The devices may further include a current transformer coupled to the conductor lines, the current transformer operable to output a secondary current corresponding to a primary current magnitude of an electrical current not flowing to the load, wherein the AC contactor is connected between the power supply and the load. Devices may further include a zero cross detection circuit operable to generate an interrupt at each of a plurality of zero crossings for a microprocessor, and determine whether to open the one or more contactors of the AC contactor in a predetermined optimum interval calculated with respect to the zero crossing points.

Devices herein may include conductor lines connected between a power supply and load, each of the conductor lines coupled to an AC contactor and a contactor control circuit, wherein the contactor control circuit is operable to open and close one or more contactors of the AC contactor. The devices may further include a current transformer coupled to the conductor lines, the current transformer operable to output a secondary current corresponding to a primary current magnitude of an electrical current not flowing to the load, wherein the AC contactor is connected between the power supply and the load. Devices may further include a zero cross detection circuit operable to generate an interrupt at each of a plurality of zero crossings for a microprocessor, and determine whether to open the one or more contactors of the AC contactor in a predetermined optimum interval calculated with respect to the zero crossing points.

Systems and methods for contact erosion mitigation are provided. To perform contact erosion mitigation, an order of opening/closing poles and/or contact relays of particular poles is altered, resulting in a sharing of potential arcing conditions amongst the poles/contact relays of these poles.

A relay diagnosis apparatus for a parallel pack assembly including a first battery pack having a first battery module and a first positive relay and a second battery pack having a second battery module and a second positive relay includes a diagnosis unit including a diagnosis switch and a diagnosis resistor connected between first and second battery pack terminals, a first detector to detect a current of the first battery module, a second detector to detect a current of the second battery module, and a control unit to collect a first and second detection values from the first and second detectors, respectively, during a first diagnosis period in which the first and second positive relays are open and the diagnosis switch is closed. The control unit determines a stuck-closed fault of the first or second positive relays based on the first and second detection values and a first threshold.

A relay failure detection circuit includes a first voltage acquiring section configured to acquire an AC voltage input to a power supply circuit and output the AC voltage as a first voltage signal, a second voltage acquiring section configured to acquire an inter-terminal voltage of a relay provided in the power supply circuit and output the inter-terminal voltage as a second voltage signal, a comparing section configured to compare a waveform of the first voltage signal and a waveform of the second voltage signal, and a determining section configured to determine a failure of the relay according to a result of the comparison.

An apparatus and method for diagnosing whether a charging and discharging switching element provided on a charging and discharging path of a battery pack operates normally. A charging and discharging switching unit having a charging and discharging switch and a fuse is installed on a charging and discharging path between a battery cell and a pack terminal. The apparatus includes a first diagnosing path a second diagnosing path, a third diagnosing path, an integrated diagnosing path having a diagnosis switching unit and a diagnosis resistor, a voltage measuring unit, and a control unit configured to turn on and off the diagnosis switching unit and determine whether the charging and discharging switching unit is operating abnormally based on the diagnosis voltage measured by the voltage measuring unit.

An error detecting method of a charging switch unit including a first charging switch and a second charging switch connected to a charging line of a battery, including: first switching one of the first charging switch and the second charging switch according to a switch control command; determining whether voltages at opposite ends of the second charging switch are similar when the switch control command indicates open and the first charging switch is opened first; determining that the first charging switch is normal when the voltages at the opposite ends of the second charging switch are similar; determining whether the voltages at the opposite ends of the first charging switch are similar when the switch control command indicates closed and the first charging switch is closed first; and determining that the first charging switch is normal when the voltages at the opposite ends of the first charging switch are similar.