Abstract: A fault protection arrangement. The fault protection arrangement may include a neutral grounding resistor including a first non-ground end, connected to a neutralizing point, and a second non-ground end. The fault protection arrangement may include a neutral grounding resistance monitor assembly, directly coupled to the second non-ground end of the neutral grounding resistor. The neutral grounding resistance monitor assembly may include comprising a signal source coupled to the neutralizing-point; a first current sense circuit coupled between the signal source and the neutralizing-point; a first voltage sense circuit coupled between the signal source and the neutralizing-point; a second current sense circuit, comprising a current sensor, coupled between the second non-ground end of the neutral grounding resistor and a protective earth connection.

Abstract: A floating two-terminal unipolar current limiting circuit arrangement implemented with enhancement mode devices and bipolar devices with a unique voltage-current operation curve. This operation curve makes this device particularly advantageous to instrumentation systems that are intended to experience large voltage transients and long-term exposure to voltages that would normally damage measurement equipment. The present current limiting device is designed to have a large impedance value prior to a “turn-on” voltage, then quickly transitions to a low-impedance state. When the conducted current exceeds a setpoint or a high-voltage event occurs, the current limiting device further transitions to the “cutoff” region, which transition resumes the initial high-impedance state. In one embodiment the threshold current may be set with internal components, while a further embodiment allows the current setpoint to be set by external components.

Abstract: A floating two-terminal unipolar current limiting circuit arrangement implemented with enhancement mode devices and bipolar devices with a unique voltage-current operation curve. This operation curve makes this device particularly advantageous to instrumentation systems that are intended to experience large voltage transients and long-term exposure to voltages that would normally damage measurement equipment. The present current limiting device is designed to have a large impedance value prior to a “turn-on” voltage, then quickly transitions to a low-impedance state. When the conducted current exceeds a setpoint or a high-voltage event occurs, the current limiting device further transitions to the “cutoff” region, which transition resumes the initial high-impedance state. In one embodiment the threshold current may be set with internal components, while a further embodiment allows the current setpoint to be set by external components.

Abstract: A fault protection arrangement. The fault protection arrangement may include a neutral grounding resistor including a first non-ground end, connected to a neutralizing point, and a second non-ground end. The fault protection arrangement may include a neutral grounding resistance monitor assembly, directly coupled to the second non-ground end of the neutral grounding resistor. The neutral grounding resistance monitor assembly may include comprising a signal source coupled to the neutralizing-point; a first current sense circuit coupled between the signal source and the neutralizing-point; a first voltage sense circuit coupled between the signal source and the neutralizing-point; a second current sense circuit, comprising a current sensor, coupled between the second non-ground end of the neutral grounding resistor and a protective earth connection.

Abstract: A gas sensor system for use in an exhaust gas tube, the system having at least two separate optical sensor assemblies that are separately positioned across the exhaust gas tube from one another, wherein the optical sensor assemblies each comprise a pair of light sources and a pair of light receivers such that light from each of the multiple light sources is received by each of the four light receivers, thereby generating multiple sets of optical measurements.