A switching amplifier circuit (200) connected to drive an impedance-based output load (230) includes high side and low side switches (201-204) configured and connected to connect first and second supply voltage lines to first and second output nodes (ANTP, ANTN) in response to gating control signals, and also includes an output current sensing circuit for measuring a current through the output load with a current sensing resistor (Rs) connected between the second supply voltage line and a source of one or more split gate-source switching transistors (203C) in the low side gate-source switching transistor, where a voltage sense circuit connected across the current sensing resistor is configured to sample a voltage across the current sensing resistor for measuring a sense current at the current sensing resistor.

The present invention relates to current measurement apparatus 100. The current measurement apparatus 100 comprises a measurement arrangement 110, 114 which is configured to be disposed in relation to a load 108 which draws a current signal, the measurement arrangement being operative when so disposed to measure the load drawn current signal. The current measurement apparatus 100 also comprises a signal source 112 which is operative to apply a reference input signal to the measurement arrangement 110, 114 whereby an output signal from the measurement arrangement comprises a load output signal corresponding to the load drawn current signal and a reference output signal corresponding to the reference input signal. The current measurement apparatus 100 further comprises processing apparatus 116 which is operative to receive the output signal and to make a determination in dependence on the reference output signal and the load output signal, the determination being in respect of at least one of the load drawn current signal and electrical power consumed by the load.

A current measurement and control circuit may comprise a shunt resistor coupled between supply and output nodes; a first resistor coupled to the supply node; a second resistor coupled to ground; and a transconductance amplifier having an input coupled to the first resistor to define a compensation node and another input coupled to the output node. The circuit may also include a first transistor having a first current terminal coupled to the compensation node and a second current terminal coupled to the second resistor to define a measurement node; and a second transistor having a first current terminal coupled to ground and a second current terminal coupled to the output node. The circuit may also include an ADC having an analog input coupled to the measurement node; an IDAC having an analog output coupled to the compensation node; and switches to set the circuit in a measurement or a compensation mode.

A current measurement device includes a shunt having sense leads, the shunt configured to be located in a current path for a current to be measured, and a Rogowski coil at least partially wrapped around the shunt, the current measuring device configured to combine signals from the shunt and the Rogowski coil. A current measurement device includes a shunt having sense leads configured to be located in a current path for a current to be measured, a Rogowski coil in series with the sense leads and at least partially wrapped around the shunt, a compensating pole connected to the Rogowski coil, and an isolation barrier connected to the compensating pole.

A device for measuring current intensities including a resistor arrangement, the resistor arrangement having at least two connection elements, at least one resistor element arranged between the connection elements, and at least one contact pin monolithically connected to one of the connection elements and being formed out of the material of the connection element. The device also includes a printed circuit board mechanically and electrically connected to the resistor arrangement, which printed circuit board has a side facing away from the resistor arrangement. The printed circuit board also includes at least one conductor track and at least one passage bore. The at least one contact pin of the resistor arrangement extends through the passage bore and has, on the side of the printed circuit board facing away from the resistor arrangement, a lateral widening. The lateral widening mechanically fixes the printed circuit board to the resistor arrangement.

Safe detection of an external load attached to an AC power outlet of a power supply stands out as one advantage of the power supply apparatus and method contemplated herein, although other advantages flow therefrom. Not least among the other advantages are a simplicity of design offering an economical and robust mechanism for detecting external loads. The contemplated mechanism relies on the application of a DC voltage to one electrical phase of the AC power outlet and the coupling of that voltage to the other electrical phase of the AC power outlet through an interconnecting resistor. With both phases respectively coupled to voltage divider circuits nominally matched in value, the divided down voltages measured from the respective phases will differ in dependence on the relative size of the interconnecting resistor and the resistive value of any load attached to the AC power outlet.

In accordance with an embodiment, a method of measuring a load current flowing through a current measurement resistor coupled between a source node and a load node includes: measuring a first voltage across a replica resistor when a first end of the replica resistor is coupled to the source node and a second end of the replica resistor is coupled to a reference current source; measuring a second voltage across the replica resistor when the second end of the replica resistor is coupled to the source node and the first end of the replica resistor is coupled to the reference current source; measure a third voltage across the current sensing resistor; and calculating a corrected current measurement of the load current based on the measured first voltage, the measured second voltage and the measured third voltage.

A current measurement device with a shunt resistor of a resistive core with an opening and measurement leads, a Rogowski coil with electrical contacts surrounding the resistive core, conductive layers on first and second sides of the resistive core, one or more insulative layers between the conductive layers and the Rogowski coil, the current measurement device configured to combine signals from the shunt resistor and the Rogowski core. The current measurement device may have a Rogowski coil on a flexible substrate at least partially wrapped around the shunt resistor. A current measurement device has a rigid substrate, vias filled with a conductive material through the rigid substrate, conductive layers on the top surface and the bottom surface connecting to the vias to form a Rogowski coil structure, one or more insulative layers directly on the coil structure, a shunt resistor directly on the one or more insulative layers.

A current sensor includes a current detection unit, a relay, a relay control unit, and a resistance value correction circuit. The current detection unit detects a detection target current based on a terminal voltage of a shunt resistor located in series with a path through which the detection target current flows and a detection resistance value for current detection corresponding to a resistance value of the shunt resistor. The relay is located in series with the path through which the detection target current flows. The relay control unit controls the relay to be turned on or off. The resistance value correction circuit calculates the resistance value of the shunt resistor as a calculated resistance value and corrects the detection resistance value based on the calculated resistance value.

An open-loop fluxgate-type current sensor is described. The current sensor includes a single winding around a core that combines drive and sense that is used as both an excitation source and a feedback element to measure current through a primary winding. The current sensor further includes an H-bridge driver to impress voltage to the single winding to cause current to saturate the core, the volage being impressed with opposing polarities repeatedly causing the core to saturate at opposing polarities. The current sensor further includes an analog transconductance integrator that continuously integrates the current to infer magnetizing force being driven into the core at the opposing polarities. The current sensor further includes a microcontroller unit (MCU) that calculates residual current based on the inferred magnetizing force being driven into the core at the opposing polarities and cause remedial action to be taken when the calculated residual current exceeds a threshold.