Disclosed are insulation resistance measuring device and method that are capable of rapidly and accurately calculating insulation resistance, despite parasitic capacitor components present in a battery pack.

A load testing device includes a terminal unit, a main relay unit, a resistance unit, and a housing. The main relay unit and the switch group are used to switch a connection state between the first R-phase resistor group and the second R-phase resistor group between series and parallel, switch a connection state between the first S-phase resistor group and the second S-phase resistor group between series and parallel, and switch a connection state between the first T-phase resistor group and the second T-phase resistor group between series and parallel. A first accommodation region to a third accommodation region are located between a fourth accommodation region and a fifth accommodation region. The second accommodation region is located between the first accommodation region and the third accommodation region. The first accommodation region accommodates the first R-phase resistor group and the second R-phase resistor group.

A device for evaluating a dynamic resistance in a conducting state of a GaN-based transistor. The device including a test circuit provided with a circuit, the GaN-based transistor, forming an arm of the circuit, the device being provided with a stage for controlling the switch elements of the circuit to alternately set the switch elements of the circuit in a first configuration and then in a second configuration, the control stage being configured to trigger a connection of a drain-source voltage measuring stage to the GaN-based transistor after the circuit is set in the first configuration, and to trigger a disconnection of the drain-source voltage measuring stage from the GaN-based transistor before the circuit is set in the second configuration.

A battery pack voltage measurement circuit including a relay unit controlling battery pack voltage measurement, first and second branching units provided between a battery pack voltage input terminal and the relay unit, and branching a battery pack voltage into different paths according to the battery pack voltage and then supplying the branched voltage to the relay unit, and a voltage distribution unit dividing the battery pack voltage supplied through the first or second branching unit and the relay unit and outputting the divided battery pack voltage to an output terminal.

Systems and Methods for capacitance testing of a unit under test with parasitic capacitance directed to a guard rail. The system includes test points, wherein the plurality of test points are divided into at least two groups; a stimulus source; a first group guard relay electrically connected to each of the test points in a first; a second group guard relay electrically connected to each of the test points in a second; a guard rail coupled to the first group guard relay and the second group guard relay; a first group return relay electrically connected to each of the test points in a first group; a second group return relay electrically connected to each of the test points in a second group; a current measurement rail coupled to the first group return relay and the second group return relay; a current meter coupled to the measurement rail; and a controller.

Systems and Methods for capacitance testing of a unit under test with parasitic capacitance directed to a guard rail. The system includes test points, wherein the plurality of test points are divided into at least two groups; a stimulus source; a first group guard relay electrically connected to each of the test points in a first; a second group guard relay electrically connected to each of the test points in a second; a guard rail coupled to the first group guard relay and the second group guard relay; a first group return relay electrically connected to each of the test points in a first group; a second group return relay electrically connected to each of the test points in a second group; a current measurement rail coupled to the first group return relay and the second group return relay; a current meter coupled to the measurement rail; and a controller.