A measuring circuit for determining the magnitude of a current flowing through a conductor, the measuring circuit having an input terminal pair that can be connected to the current transformer with a first switch, which connects a measuring resistor between the input terminals in a current measuring position, and which, in a voltage measuring position, separates the measuring resistor from at least one of the input terminals, and having an output terminal pair, at which, alternatively, a voltage-dependent measuring voltage present at the input terminal pair or a current-dependent measuring voltage present at a first measuring point of the measuring resistor can be tapped. The measuring circuit includes a changeover switch which can be switched synchronously with the switch. The changeover switch is used to connect an output terminal to the first measuring point in the current measuring position, and to the second measuring point in the voltage measuring position.

A sensor includes a sensing element configured to generate a sensing element output signal indicative of a sensed parameter and a signal path responsive to the sensing element output signal and having at least one of an adjustable gain or an adjustable offset, wherein the signal path is configured to generate a sensor output signal indicative of the sensed parameter. A supply voltage detector is configured to generate a supply voltage signal indicative of which of a plurality of voltage ranges a supply voltage of the sensor falls within and at least one of the adjustable gain or the adjustable offset is adjustable in response to the supply voltage signal.

A current sensor includes an element that is in a high-resistance state when an absolute value of a current flowing between a first terminal and a second terminal is within a first range, and changes to a low-resistance state in which a resistance value is lower than that in the high-resistance state when the absolute value of the current exceeds the first range, and a circuit that supplies a current to be measured to the element, and senses a value of the current to be measured based on at least one of voltages of the first terminal and the second terminal.

A current sensor includes an element that is in a high-resistance state when an absolute value of a current flowing between a first terminal and a second terminal is within a first range, and changes to a low-resistance state in which a resistance value is lower than that in the high-resistance state when the absolute value of the current exceeds the first range, and a circuit that supplies a current to be measured to the element, and senses a value of the current to be measured based on at least one of voltages of the first terminal and the second terminal.

An auto ranging ammeter that allows improved measurement of rapidly changing, high-dynamic range electrical currents. The ammeter computes current during range switches by using digital signal processing to combine voltage measured over both a variable shunt resistor and a fixed shunt resistor. The ammeter uses fast comparators and digital processing to select the appropriate shunt resistor. The auto ranging ammeter includes a voltmeter which enables the device to output current, voltage, power, charge, and energy consumed by a target device under test.

A measurement apparatus has a current sensor and at least one A/D converter, which current sensor has at least two channels (CH1, CH2), via which channels (CH1, CH2) the current sensor (30) respectively provides a measurement signal (CH1_SIG, CH2_SIG) characterizing the current. The at least two channels (CH1, CH2) include a first channel (CH1) and a second channel (CH2), which second channel (CH2) is designed to measure a greater maximum current than the first channel (CH1). Also described is a method for measuring a current flowing through a conductor by way of the measurement apparatus.

A semiconductor device with the highly precise current detecting function is provided. Current detection is performed using a semiconductor device in which two semiconductor chips are mounted in one package. The first semiconductor chip is provided with an electric power supply transistor to supply power to a load via a load driving terminal, and a current detection circuit to detect a current flowing through the load driving terminal. In the inspection process of the semiconductor device, the electrical property of the current detection circuit in the first semiconductor chip is inspected, and the information on a correction equation obtained as the inspection result is written in a memory circuit of the second semiconductor chip. The second semiconductor chip corrects the detection result obtained by the current detection circuit based on the information on the correction equation written in the memory circuit concerned.

The present disclosure relates to an insulation resistance measuring device and method, including a parameter resistance connected to a negative electrode terminal of a battery; a shunt resistance connectable to the parameter resistance; a current detection circuit including an operational amplifier configured to detect and output voltage between both ends of the shunt resistance; and a control unit configured to determine the insulation resistance of the battery using a switch control terminal configured to control a switch connected between the parameter resistance and the shunt resistance to an ON or OFF state, a detection signal output terminal configured to selectively apply a first high voltage signal and a first low voltage signal to the shunt resistance, a control signal output terminal configured to apply a control voltage signal to the operational amplifier to adjust an output voltage of the operational amplifier within a predetermined range, an ADC connected to an output terminal of the operational amplifier, and a predefined insulation resistance formula that includes, as a parameter, a first voltage change amount with respect to the output voltage of the operational amplifier being measured through the ADC when the first high voltage signal and the first low voltage signal are applied to the shunt resistance.

Controlling a switching element in accordance with a voltage output from a signal amplifying circuit enables adjusting a voltage to be received by a current calculation circuit. Even when a range of a air volume to be used is wide and a range of output of a DC motor is wide, or a current flowing through the DC motor has a wide range, a resistance value of a shunt resistor and an amplification factor of a signal amplifying circuit are not required to be reduced, and thus current detection accuracy of the DC motor can be improved.

Controlling a switching element in accordance with a voltage output from a signal amplifying circuit enables adjusting a voltage to be received by a current calculation circuit. Even when a range of a air volume to be used is wide and a range of output of a DC motor is wide, or a current flowing through the DC motor has a wide range, a resistance value of a shunt resistor and an amplification factor of a signal amplifying circuit are not required to be reduced, and thus current detection accuracy of the DC motor can be improved.