Provided is a two axis test fixture, which can include systems and associated methods. Some methods described also include implementing and/or controlling a two-axis test fixture. Systems and computer program products are also provided. A test fixture is used to test, calibrate, or validate an IMU. The test fixture is operable to rotate a device under test (e.g., IMU) along two axes while mounted to a turntable. The rotation of the turntable is enabled via multiple slip rings, rotational bearings, and standoff fixtures. Testing of the device along greater than two axes is achieved through rotation of the device under test on the turntable, and revolutions of the device under test about an axle.

Passive monitoring the integrity of current sensing devices and associated circuitry in GFCI and AFCI protective devices is provided. A protection circuit interrupter employs a capacitively coupled noise signal obtained by an arrangement of one or both of line side arms relative to a Rogowski coil. The noise signal is monitored while the line and load sides of a protective circuit interrupter are disconnected, and the connection of the line and load sides disabled if the noise signal fails to correlate sufficiently to a reference noise cycle. When the line and load sides are connected, the RMS value of the observed current signal is monitored such that the line and load sides are disconnected if the observed current signal fails to meet an RMS threshold. The observed current signal is compensated by subtracting the reference noise cycle prior to monitoring for the fault condition applicable to the protective device.

Passive monitoring the integrity of current sensing devices and associated circuitry in GFCI and AFCI protective devices is provided. A protection circuit interrupter employs a capacitively coupled noise signal obtained by an arrangement of one or both of line side arms relative to a Rogowski coil. The noise signal is monitored while the line and load sides of a protective circuit interrupter are disconnected, and the connection of the line and load sides disabled if the noise signal fails to correlate sufficiently to a reference noise cycle. When the line and load sides are connected, the RMS value of the observed current signal is monitored such that the line and load sides are disconnected if the observed current signal fails to meet an RMS threshold. The observed current signal is compensated by subtracting the reference noise cycle prior to monitoring for the fault condition applicable to the protective device.

A control module of a power calibration circuit comprises a control unit, a main voltage feedback unit and an auxiliary voltage feedback unit, the control unit is connected to at least one power switch, the main voltage feedback unit is connected to an output terminal of the power calibration circuit and the control unit, the auxiliary voltage feedback unit is connected to the output terminal and the control unit, the auxiliary voltage feedback unit comprises a voltage dividing circuit connected to the output terminal and having at least one voltage dividing node, and a voltage limiting circuit connected to the voltage dividing node and the control unit, the voltage limiting circuit has a first state when a voltage of the voltage dividing node is not higher than a reference voltage, and a second state when a voltage of the voltage dividing node is higher than the reference voltage.

A control module of a power calibration circuit comprises a control unit, a main voltage feedback unit and an auxiliary voltage feedback unit, the control unit is connected to at least one power switch, the main voltage feedback unit is connected to an output terminal of the power calibration circuit and the control unit, the auxiliary voltage feedback unit is connected to the output terminal and the control unit, the auxiliary voltage feedback unit comprises a voltage dividing circuit connected to the output terminal and having at least one voltage dividing node, and a voltage limiting circuit connected to the voltage dividing node and the control unit, the voltage limiting circuit has a first state when a voltage of the voltage dividing node is not higher than a reference voltage, and a second state when a voltage of the voltage dividing node is higher than the reference voltage.

A battery management system includes a microcontroller unit which transmits and receives communications information through a communications input/output terminal, a fault generator unit which generates fault information and transmits the fault information through a fault information output terminal, and a battery cell monitoring unit which is coupled to the communications input/output terminal and the fault information output terminal and diagnoses an operation of internal function based on the fault information transmitted from the fault generator unit and outputs an internal diagnosis result value to the microcontroller unit.

An electric meter includes a meter shell configured to be within an outer utility box. A meter socket and blades are for coupling to openings of the socket. The openings include utility-side and premises-side openings for the blades to extend into. A meter processor is coupled to measurement circuitry, and to a communications unit including a transceiver. A gas sensor is positioned proximate to the blades for sensing ≥1 gaseous compound product resulting from an arc discharge across air involving the blades. During operation of the electric meter, responsive sensing a presence of the gaseous compound product, the gas sensor generates an output signal. Responsive to the output signal being above a predetermined threshold level, the electric meter triggers an alert signal that is transmitted to an advanced metering infrastructure (AMI) which indicates an identity of the electric meter and that the electric meter had experienced the arc discharge.

A circuit for an inductive conductivity sensor comprises: a secondary coil having a first coil terminal and a second coil terminal, a switch having a first switch terminal, a second switch terminal, a third switch terminal, a first potential terminal, and a control unit having a first control terminal and a second control terminal, wherein the first coil terminal is connected to the first control terminal and the second coil terminal is connected to the first switch terminal, wherein the second switch terminal is connected to the first potential terminal and the third switch terminal is connected to the second control terminal.

Circuitry comprising: a voltage monitoring path; a current monitoring path; a reference element of a predefined impedance; and processing circuitry, wherein in operation of the circuitry in a calibration mode of operation: the voltage monitoring path is operative to output a signal indicative of a voltage across the reference element in response to a reference signal applied to the reference element; the current monitoring path is operative to output a signal indicative of a current through the reference element in response to the reference signal; and the processing circuitry is operative to: receive the signal indicative of the voltage across the reference element and the signal indicative of the current through the reference element; generate an estimate of an impedance of the reference element; and determine a compensation parameter for an element of the circuitry for compensating for a difference between the estimate of the impedance and the predefined impedance of the reference element.

A method of calibrating an impedance-matching current sensor (IMCS) is provided. The IMCS has an equivalent sensing impedance and is connected in parallel to an object under test. The method includes steps of: using an alternating-current (AC) current source to provide a first AC current flowing through the object under test and provide a second AC current flowing through the IMCS; designing the equivalent sensing impedance to make the first AC current much greater than the second AC current; proportionally converting the second AC current into a sense voltage; and adjusting a magnitude of the sense voltage to be proportional to a magnitude of the first AC current. Accordingly, it is to significantly overcome problems of unreliability and instability of the DC-to-DC conversion system caused by temperature, aging, DC bias variation, or parasitic effect, thus maintaining correct sensed results of the current sensor in transient response optimization.