Implants or sensors often include and rely on inductive and ferromagnetic electrical components to measure and communicate data outside of the body to an external device, creating a safety concern when a patient with these implants or sensors must undergo an MRI scan. Further, various external devices that include inductive and ferromagnetic electrical components are exposed to potentially damaging MRI scans. An electrical coil assembly can include an electrical coil that includes a substrate and an electrical conductor supported by a first face of the substrate. In an example, the electrical coil assembly further includes a fuse element that is configured to move from a disengaged position in which the electrical fuse conductor is out of contact with the electrical conductor to an engaged position in which the electrical fuse conductor contacts the electrical conductor so as to define a short circuit.

An electronic device for the diagnosis of insulation loss of an energized electrical apparatus, with respect to a ground. The device includes a first resistance-switch group and a second resistance-switch group, connectable or disconnectable in a controlled manner, and also a first measurement circuit and a second measurement circuit, arranged in parallel to the first and second resistance-switch groups, respectively. The first and second measurement circuits include respective first and second detection circuits, first and second charge modulation circuits and first and second partition resistors (RB.sub.minus, RB.sub.plus). The first and second charge modulation circuits allow a dynamic switching measurement technique. Moreover, a method is described for measuring the insulation resistances (RI.sub.minus, RI.sub.plus) of an energized electrical apparatus with respect to ground, in which the method is carried out by a device according to the invention. Finally, a self-diagnosis method of device is described.

An insulation resistance detection circuit is coupled to a positive end and a negative end of a DC power source, and is used to detect a positive insulation resistance between the positive end and a ground point and detect a negative insulation resistance between the negative end and the ground point. A detection unit sets a first estimated resistance and a second estimated resistance, and acquires a first voltage based on turning on the switch and acquires a second voltage based on turning off the switch. The detection unit calculates a third voltage and a fourth voltage according to the first estimated resistance and the second estimated resistance so as to detect the positive insulation resistance and the negative insulation resistance when the third voltage is equal to the first voltage and the fourth voltage is equal to the second voltage.

An apparatus for evaluating an electrical insulator includes: a frame having a base and a pair of spaced-apart resilient arms each having a distal end; and a flexible probe disposed between the arms, the flexible probe being generally U-shaped and having a pair of distal ends, each distal end of the probe being connected to a respective distal end of one of the arms.

A support bracket for a fuse cutout may include an insulating rod with a first threaded standoff at a top end of the insulating rod and a second threaded standoff at a bottom end of the insulating rod. One or more shed sleeves may be secured over an outside surface of the insulating rod between the first threaded standoff and the second threaded standoff. The interior surface of the one or more shed sleeves forms a dielectric interface between the outside surface of the insulating rod and the interior surface of the shed sleeve. A mounting bracket may be secured to a portion of the support bracket between the first threaded standoff and the second threaded standoff. The one or more shed sleeves may be pre-molded prior to installation over the insulating rod.

A system for checking the electrical insulation in converters for electric cars comprises at least one voltage generator connected to at least one line to be monitored of a high-voltage converter for electric vehicles and connected to the ground of said converter, and at least one current detection unit operatively connected to said voltage generator and configured to detect any current possibly present on the voltage generator and to generate a warning signal in the event of detection of the current.

A test fixture for testing a material according to a particular test procedure. A metallic base and four non-conductive side panels are affixed along a periphery of the base to form an internal cavity, and a non-conductive top cover is hingedly connected to one side panel. A metallic bottom electrode has an upper surface for holding a test material and a lower portion installed into a first aperture in an upper surface of the base. A metallic top electrode has a lower portion with a lower surface for contacting the test material and an upper portion extending out of a cover aperture in the top cover when the lower surface is in contact with the test material. A voltage source is coupled to perform the testing via a terminal on the base and the upper portion of the top electrode.

A motor driving device includes, a PWM converter that performs power conversion between AC power and DC power in a DC link, an inverter that converts the DC power in the DC link to AC power for a motor and that converts the AC power from the motor to DC power for returning to the DC link, a power storage unit that stores the DC power, a switch that connects or disconnects between an AC power supply and the PWM converter in response to a command, and a command unit that continues outputting a connection command to the switch while a DC voltage in the DC link is boosted up to a prescribed voltage by the DC power, and that initiates outputting a disconnection command to the switch after the DC voltage in the DC link reaches the prescribed voltage and before the inverter initiates powering operation.

Systems and methods are disclosed for on-line monitoring of the condition of insulation in electrical devices employing a differential current sensor. In certain embodiments a monitor that can be fitted to existing electrical devices by attachment of the sensor to a pair of phase cables is provided. In other embodiments, an electrical device configured with an insulation monitor is provided.

Embodiments of the present disclosure include a method of operating an arc fault detection system, an arc fault detection system, and a system. An embodiment is a method of operating an arc fault detection system coupled to a power line, the method including determining one or more arc fault detection windows in power line signals on the power line, the power line signals comprising a communication signal and an alternating current (AC) power signal. The method further includes receiving the power line signals from the power line during the one or more arc fault detection windows, and performing arc fault detection processing on the received power line signals.