A device for measuring resistance of a ground tap and a charger for an on-board vehicle including the device. The device includes a current source and an ammeter disposed on a first electrical branch, provided to link a phase of a power supply network with the ground of the installation; a second electrical branch provided to link a neutral wire of the power supply network with the ground of the installation, including a resistor across terminals of which is connected a voltmeter, and a first capacitor in series with the resistor; and a third electrical branch is provided for linking the neutral wire of the network with the ground of the installation, and including, on the third branch, in parallel with the first capacitor and with the first resistor, a second capacitor of higher value than the first capacitor.

A stainless steel having a low surface contact resistance for fuel cell separators is provided. The stainless steel has a Cr content of 16 to 40 mass % or more. The stainless steel includes a region having a fine textured structure on its surface, and the area percentage of the region is 50% or more, preferably 80% or more. The region having a fine textured structure is a region which has a structure having depressed portions and raised portions at an average interval between depressed portions or raised portions of 20 nm or more and 150 nm or less when observed with a scanning electron microscope.

A robotic system may include an electrical ground line and a protective earth line electrically coupled to the electrical ground line. The robotic system may also include a testing circuit coupled to the protective-earth line via an isolation capacitor. The testing circuit may include a lock-in amplifier and may be configured to measure an impedance for the protective-earth line through the isolation capacitor. Methods for testing or monitoring protective-earth lines are also disclosed herein.

A system comprises a prober unit, and a control unit. The prober unit comprises electrical probes. The control unit configured to: cause the prober unit to make contact between the electrical probes and contact pads of a target device; cause the prober unit to increment a contact overdrive by a specified amount to increase a contact pressure between the electrical probes and the contact pads of the target device; measure a contact resistance between the electrical probes and the contact pads of the target device, subsequent to incrementing the contact overdrive; compare the measured contact resistance with a contact resistance threshold; and determine whether to perform an electrical characterization measurement of the target device, based on a result of comparing the measured contact resistance with the contact resistance threshold.

A control method of a ground fault detection apparatus for detecting a decrease in an insulation resistance of a system including a battery that is not grounded and a Y capacitor includes an insulation-resistance-decrease detection step of controlling a switching portion to measure a charging voltage of the first capacitor and to perform a detection of a decrease in the insulation resistance based on the measured charging voltage of the first capacitor, wherein the insulation-resistance-decrease detection step is initiated when a first period has elapsed from a startup process for starting up the ground fault detection apparatus is finished.

A method for determining a contact resistance may include performing voltage and current measurements associated with a pin of a device under test (DUT) using a parameter measurement circuit, obtaining at least three voltage-current measurement pairs. An emission coefficient may be determined from the voltage-current measurement pairs. A contact resistance may be calculated from the emission coefficient and the voltage-current measurement pairs and stored.

An integrated circuit includes an output circuit having a first terminal adapted to couple to an external power supply, a second terminal adapted to couple to a reference potential, and a third, control terminal. The first and second terminals of the output circuit provide output terminals of the integrated circuit. The integrated circuit further includes an impedance measurement circuit responsive to the external power supply to generate a control signal for coupling to the control terminal of the output circuit. The control signal controls a current level associated with the output circuit. A corresponding method is also described.

Procedure for measuring the impedance of a grounding system that comprises a loop, the procedure comprises for each frequency fi of a set of frequencies F of a frequency sweep applied to the loop of the grounding system, generating a modulating signal S.sub.signal (2) with a fixed frequency fm, generating a carrier signal S.sub.carrier (1) with the frequency fi, and obtaining an amplitude modulated signal S.sub.modulated (3) with frequency components of the frequencies fm and fi and based on S.sub.signal (2) and S.sub.carrier (1).

Procedure for measuring the impedance of a grounding system that comprises a loop, the procedure comprises for each frequency fi of a set of frequencies F of a frequency sweep applied to the loop of the grounding system, generating a modulating signal S.sub.signal (2) with a fixed frequency fm, generating a carrier signal S.sub.carrier (1) with the frequency fi, and obtaining an amplitude modulated signal S.sub.modulated (3) with frequency components of the frequencies fm and fi and based on S.sub.signal (2) and S.sub.carrier (1).

An apparatus and method for the measurement of a resistance of a switching contact of an electrical circuit breaker. A first resistance value across the circuit breaker is determined while the circuit breaker is grounded at both sides and the switching contact is closed. Further, a second resistance value across the circuit breaker is determined while the circuit breaker is grounded at both sides and the switching contact is open. The resistance of the closed switching contact is then determined based on the first resistance value and the second resistance value.