An AD converter with self-calibration function that does not require an instrument for calibration, and includes: a reference voltage unit that generates a reference voltage; a summation and conversion unit that has two or more unit voltages serving as units of amount of change in a summed voltage, and during conversion, sums up any one unit voltage of the two or more unit voltages until the summed voltage exceeds the reference voltage, with an input voltage being an initial value of the summed voltage; and a control unit including a calibration control section that calibrates the two or more unit voltages and an offset voltage of a comparator at a time of calibration, and a conversion control section that determines a polarity of the offset voltage of the comparator and thereafter converts the input voltage to a digital value during conversion.

A current measuring system for measuring current from a conductor comprises a first and second circuit and a current measurer connected to a conductor connected to a first power source. The first circuit comprises an inverting operational amplifier, which generates a first threshold signal when current flows into the first power source. The second circuit comprises a biasing circuit and a non-inverting operational amplifier, which generates the first threshold signal at the second output when current flows out of the first power source.

In an embodiment, a circuit includes a first branch coupled between a first node and a second node, the first branch including a first ceramic capacitor, the first ceramic capacitor including terminals configured to receive a first voltage applied therebetween. The circuit further includes a second branch coupled between the first node and a third node, the second branch including a second ceramic capacitor that is substantially identical to the first ceramic capacitor, the second ceramic capacitor including terminals configured to receive a second voltage applied therebetween. The circuit further includes a control circuit configured to modify the second voltage until a first current passing through the second node is substantially equal to a second current passing through the third node.

To improve cooling capability, power conversion apparatus 1 that converts a direct current voltage into an alternating current voltage includes: first substrate 100 on which power conversion circuit 2 is mounted; second substrate 200 on which driving circuit 3 that drives power conversion circuit 2 is mounted; and shield plate 300 that is disposed between first substrate 100 and second substrate 200, and first substrate 100 is a metal substrate.

A device for measuring oxygen saturation includes circuitry configured to determine a measured difference of forward voltage based on a first forward voltage at a first light emitting diode and a second forward voltage a second light emitting diode and determine that the first and second light emitting diodes are valid based on a calibrated difference of forward voltage and the measured difference of forward voltage. In response to the determination that the first and second light emitting diodes are valid, the circuitry is configured to determine an oxygen saturation level.

A device for measuring oxygen saturation includes circuitry configured to determine a series resistance for a light emitting diode based on a first diode voltage at the light emitting diode for a first current, a second diode voltage at the light emitting diode for a second current, and a third diode voltage at the light emitting diode for a third current. The circuitry is further configured to determine an intensity of a received photonic signal corresponding to an output photonic signal output using the light emitting diode. The circuitry is further configured to determine an oxygen saturation level based on the intensity of the received photonic signal and the series resistance.

A current sensor that is less affected by the residual magnetization is provided. A current sensor of the present invention has a magnetic circuit that is magnetized by electric current; a first magnetic field detecting element that is positioned where a magnetic field, when the electric current is present, is directed in a same direction as a magnetic field that is caused by residual magnetization of the magnetic circuit when the electric current is not present; and a second magnetic field detecting element that is positioned where a magnetic field, when the electric current is present, is directed opposite to a direction of a magnetic field that is caused by residual magnetization of the magnetic circuit when the electric current is not present.

A monitoring set-up to detect supply-line faults for a control unit, including at least two internal current-carrying supply lines, which are redundant with respect to each other, are situated inside of the control unit, and are connected electrically, on one end, to external supply lines, respectively, and, on the other end, to a common, internal supply-potential layer of the control unit; a signal detector, which inductively picks up a flow of current through the individual internal supply lines and outputs at least one corresponding measuring signal; and an evaluation and control unit, which evaluates the at least one measuring signal to detect supply-line faults. A method of detecting supply-line faults for a control unit, using such a monitoring set-up, is also described.

The voltage-measuring device is adapted to perform voltage measurements on a laminate assembly formed of separators and of at least one membrane electrode assembly stacked to form one or more electrochemical cells. It includes two measuring plates on which are distributed a plurality of electrical contacts spaced apart from each other and electrically insulated from each other, the measuring plates being configured to be arranged on either side of the laminate assembly, the measuring face of each measuring plate being applied against a respective separator in such a way that the electrical contacts located on this measuring face are in contact with the separator.

A measuring system for detecting a physical parameter, includes a measuring sensor for detecting the physical parameter, which sensor has a first, second and at least one third terminal. The measuring system also includes a first power supply unit for outputting electrical energy to the measuring sensor with a first voltage with respect to a first ground potential via the first and the second terminal, and a second power supply unit for outputting electrical energy to the measuring sensor with a second voltage with respect to a second ground potential via the third and the second terminal or a fourth terminal. The first ground potential can differ from the second ground potential at least temporarily. The first power supply unit includes an additional voltage source via which the second terminal is electrically connected to the first ground potential.