The present disclosure describes an apparatus, system, and method of use for detecting electrical faults in a multiphase electric machine. Often in platforms which require redundant reliability or have no readily available electrical connection to earth use ungrounded electrical architectures. This allows the system to continue normal operation even if there is an unintended short circuit or current path (electrical fault) between a phase of an electric machine and its case or some other part of the platform. It is important to be able to readily identify any fault in the phase windings of machinery operating in an ungrounded electrical architecture. Since a single fault in an ungrounded system will not cause any additional current draw or otherwise affect the system, it can be difficult to detect that a fault has even occurred. This provides an advanced warning system.

A bidirectional flat clamp device includes a first device node and a second device node. The bidirectional flat clamp device also includes a first switch and a second switch coupled in series between the first and second device nodes. The bidirectional flat clamp device also includes at least one switch driver coupled to the first and second switches. The bidirectional flat clamp device also includes a first current path between the first and second device nodes, the first current path having a first diode, a voltage sensor circuit, and a second diode. The bidirectional flat clamp device also includes a second current path between the first and second device nodes, the second current path having a third diode, the voltage sensor circuit, and a fourth diode.

A circuit comprises an optical coupling including an illuminator optically coupled to an optical sensor to output a voltage from the optical sensor based on intensity of illumination from the illuminator. The circuit includes a voltage input node with a resistance connected in series between the voltage input and a Zener diode. A method includes powering an illuminator with current from a first voltage input node. The method includes sensing illumination level in illumination from the illuminator with a sensor and outputting output proportionate to illumination sensed by the sensor indicative of voltage detected at the voltage input node. The method can include limiting current between the voltage input node and the illuminator.

A gate driver IC includes a first diode, a second diode, a first comparator, a second comparator, and a judgement circuit. The first comparator compares a first potential difference between both ends of the first diode and a first threshold. The second comparator compares a second potential difference between both ends of the second diode and a second threshold. Based on comparison results of the first comparator and the second comparator, the judgement circuit determines occurrence of disconnection.

A measurement device configured to deliver a voltage corresponding to an overlay of an input voltage applied to the terminals of the measurement device and of an image voltage of a current circulating in a first capacitor to the terminals of which the input voltage is applied, the measurement device includes a shunt filter intended to be mounted in parallel with the first capacitor and comprising a second capacitor and a first resistor mounted in series with the second capacitor, a second resistor mounted in parallel with the second capacitor.

A voltage differential testing circuit can include a first positive line configured to connect to a positive voltage source, and a first negative line configured to connect to a negative voltage source. The circuit can include a plurality of components arranged and configured to output an output voltage when a voltage differential between a positive voltage line and a negative voltage line is within a voltage range.

In accordance with at least one aspect of this disclosure, a circuit can include a voltage input and a first inductor coil of a first channel configured to interface a second inductor coil of a second channel to induce voltage to a winding (e.g. a solenoid) via the first channel or the second channel. At least a first wraparound circuit of the first channel can be operatively connected to the first inductor coil to prevent interference from the second inductor coil from activating a wraparound circuit operatively connected to the first inductor coil.

A voltage transient detector includes circuitry for transmitting electrical current through a light emitting diode and a fuse that is serially connected between the light emitting diode and a reference potential, such that the light emitting diode is illuminated when the fuse is not blown. The voltage transient detector also includes circuitry for transmitting a controlled amount of electrical current through the fuse in conjunction with an occurrence of a voltage transient at a voltage measurement location, where the voltage transient exceeds a set transient threshold voltage. The controlled amount of electrical current transmitted through the fuse causing the fuse to blow and the light emitting diode to turn off, thereby indicating occurrence of the voltage transient at the voltage measurement location.

Various examples are provided for on-state voltage sensing for in-situ monitoring and prognostics. In one example, an on-state monitoring circuit includes clamping circuitry including high-side and low-side voltage clamping circuits associated with high-side and low-side switching devices of a half-bridge (HB) leg of an converter, on-state voltage circuitry including high-side and low-side voltage measurement circuits, the high-side and low-side circuits referenced to the positive and negative buses of the converter respectively, and output circuitry including high-side and low-side isolation circuits that provide isolated outputs referenced to a control ground of the converter. In another example, an on-state voltage measurement circuit includes clamping circuitry including high-side and low-side voltage clamping circuits referenced to a common point between high-side and low-side switching devices of a HB leg, on-state voltage circuitry including high-side and low-side voltage measurement circuits and a voltage merger circuit, and output circuitry including an isolation circuit providing a single output containing both high-side on-state voltage and low-side on-state voltage.

A measurement device configured to deliver a voltage corresponding to an overlay of an input voltage applied to the terminals of the measurement device and of an image voltage of a current circulating in a first capacitor to the terminals of which the input voltage is applied, the measurement device includes a shunt filter intended to be mounted in parallel with the first capacitor and comprising a second capacitor and a first resistor mounted in series with the second capacitor, a second resistor mounted in parallel with the second capacitor.