A processing system comprises a tool that processes a workpiece composed of a metal member, a motor that rotates the workpiece or the tool, a control unit that controls the motor, and a measurement unit that obtains an electrical quantity of the motor, wherein the control unit changes a rotational speed of the motor based on a difference between a first electrical quantity and a second electrical quantity, the first electrical quantity is an electrical quantity obtained by the measurement unit while the motor rotates before the workpiece is processed, and the second electrical quantity is an electrical quantity obtained by the measurement unit while the workpiece is processed.

To provide a controller for AC rotary machine which can detect the field current flowing through the field winding with good accuracy and can suppress the heat generation of the current detection circuit. A controller for AC rotary machine is provided with a bus current detection circuit that detects a bus current which flows through a connection path between a DC power source and a converter; a converter switching control unit that switches a power supply path and a circulation path of the converter; and a current calculation unit that calculates a field current flowing into the field winding, based on a bus current in suppling power detected when switching to the power supply path and a bus current in circulating detected when switching to the circulation path.

To provide a controller for AC rotary machine which can detect the field current flowing through the field winding with good accuracy and can suppress the heat generation of the current detection circuit. A controller for AC rotary machine is provided with a bus current detection circuit that detects a bus current which flows through a connection path between a DC power source and a converter; a converter switching control unit that switches a power supply path and a circulation path of the converter; and a current calculation unit that calculates a field current flowing into the field winding, based on a bus current in suppling power detected when switching to the power supply path and a bus current in circulating detected when switching to the circulation path.

A system may include an output power stage driver comprising a plurality of parallel-coupled field-effect transistors and a current sensor comprising a sense field-effect transistor matched to a matched field-effect transistor of the plurality of parallel-coupled field-effect transistors and gate-coupled and source-coupled to the matched field-effect transistor. The current sensor may be configured to measure a reference voltage across the sense field-effect transistor, measure a sense voltage across the matched field-effect transistor, and determine a current through the output power stage driver based on a comparison of the reference voltage to the sense voltage.

A system may include an output power stage driver comprising a plurality of parallel-coupled field-effect transistors and a current sensor comprising a sense field-effect transistor matched to a matched field-effect transistor of the plurality of parallel-coupled field-effect transistors and gate-coupled and source-coupled to the matched field-effect transistor. The current sensor may be configured to measure a reference voltage across the sense field-effect transistor, measure a sense voltage across the matched field-effect transistor, and determine a current through the output power stage driver based on a comparison of the reference voltage to the sense voltage.

Devices and methods for detection of active return loss for an antenna element of a plurality of antenna elements of a phased array antenna are provided. An exemplary device can convert a voltage differential at an input of a power amplifier (PA) to first current. The device can convert a coupled voltage corresponding to a signal transmitted from the PA to a respective antenna element, to a second current. The device can convert a reflected voltage corresponding to a signal reflected from the respective antenna element, to a third current. The device can convert the first current, the second current, and the third current to an output voltage at a generator output. The device can further have a controller that can adaptively generate codebooks for transmission based on the output voltage.

Devices and methods for detection of active return loss for an antenna element of a plurality of antenna elements of a phased array antenna are provided. An exemplary device can convert a voltage differential at an input of a power amplifier (PA) to first current. The device can convert a coupled voltage corresponding to a signal transmitted from the PA to a respective antenna element, to a second current. The device can convert a reflected voltage corresponding to a signal reflected from the respective antenna element, to a third current. The device can convert the first current, the second current, and the third current to an output voltage at a generator output. The device can further have a controller that can adaptively generate codebooks for transmission based on the output voltage.

An apparatus for measuring a current being supplied to a load includes a first pass transistor to couple a first sense resistance to the load when the first pass transistor is enabled and a second pass transistor to couple a second sense resistance to the load when the second pass transistor is enabled. An error amplifier determines a difference between a voltage being supplied to the load and a reference voltage and to supplies an error amplifier output signal according to the difference. A switch couples the error amplifier output signal to a gate of the first pass transistor or to a gate of the second pass transistor. Control logic controls the switch according to a value of the current being supplied to the load. The voltage being supplied to the load is controlled using the error amplifier output signal that is selectively coupled to the gate of the first pass transistor or the gate of the second pass transistor.

An apparatus for measuring a current being supplied to a load includes a first pass transistor to couple a first sense resistance to the load when the first pass transistor is enabled and a second pass transistor to couple a second sense resistance to the load when the second pass transistor is enabled. An error amplifier determines a difference between a voltage being supplied to the load and a reference voltage and to supplies an error amplifier output signal according to the difference. A switch couples the error amplifier output signal to a gate of the first pass transistor or to a gate of the second pass transistor. Control logic controls the switch according to a value of the current being supplied to the load. The voltage being supplied to the load is controlled using the error amplifier output signal that is selectively coupled to the gate of the first pass transistor or the gate of the second pass transistor.

A DC meter for an electrical vehicle charging station having a pair of DC power supply lines extending from a charging station controller to an electrical vehicle connector, the DC meter comprising a meter unit and a sensor unit. The meter unit comprises a user interface, a sensor interface for connection to the sensor unit, a metering interface for connection to the charging station controller, and a microprocessor configured to receive and process signals received from the sensor unit, to exchange data with the charging station controller and to receive commands from the user interface and output information to the user interface. The sensor unit is separate and connected at a point distal from the meter unit via an interconnection cable for the transmission of measurement signals.