Techniques for detecting an inrush current in a power transformer in are disclosed. For example, the presence of an inrush current on a current path in a power transformer may be determined by receiving a signal from a Rogowski coil positioned on a current path of a power transformer, the signal corresponding to a current flowing in the current path; sampling the received signal to produce samples of the received signal; and analyzing the samples of the received signal relative to at least two criteria to determine whether an inrush current is present. When an inrush current is present, operation of a protective relay is blocked.

An over current protection circuit arranged for providing an over current signal, the over current protection circuit includes a compare stage arranged for determining that a blanking time value is higher than a predefined reference value, an output stage arranged for outputting the over current signal based on the determination, a blanking time stage arranged for generating the blanking time value, and the blanking time stage is arranged to start generating the blanking time value upon a load current exceeding a predefined set current, the blanking time stage is further arranged to modulate the blanking time value based on a magnitude in which the load current exceeds the predefined set current.

A circuit for detecting discrete inputs includes a first line replaceable unit (LRU). A second LRU includes an LRU circuit that includes a power source, a diode set coupled to the power source, a resistor R3 connecting from a node Vc between the diode set and the first LRU to ground, and a logic detection and processing circuit. The logic detection and processing circuit is operably connected to the diode set, and is configured to detect a state of the first LRU based on a detected voltage. The detected voltage is either open, or 28-Volts.

Embodiments of the present disclosure relate to a multi-function circuit. The circuit comprises a low side circuit that is comprised with a first set of enhancement mode transistors. The half bridge circuit also includes a high side circuit that is comprised of a second set of transistors. Each of the enhancement mode transistors of the first set and second set of enhancement mode transistors are Gallium Nitride (GaN) transistors. In some embodiments, the GaN transistors are High Electron Mobility Transistors (HEMTs). In additional embodiments, the GaN transistors are configured and operated as saturated switches. In further embodiments, the half bridge circuit is designed as a discrete circuit. Additionally, each of the first set and second set of transistors, diodes, resistors, and all passive elements are discrete components arranged to form a half bridge circuit. In fact, the entire half bridge circuit is built from discrete components.

A detection circuit includes an under-voltage circuit. The under-voltage circuit includes a first GaN high electron mobility transistor (HEMT) configured to operate as both a voltage comparator and a voltage reference. The detection circuit can also include an over-voltage detection circuit. The over-voltage detection circuit includes a second GaN HEMT that is also configured to operate as both a voltage comparator and a voltage reference. Each of the under-voltage circuit and over-voltage circuit includes a GaN HEMT logic inversion element to provide electrical hysteresis. Also, the under-voltage detection circuit and the over-voltage detection circuit are configured to provide outputs to a single power good terminal. The first GaN HEMT can be configured to use its gate source threshold voltage for voltage comparison and reference. The second GaN HEMT can be configured to use its gate source threshold voltage for voltage comparison and reference.

This application discloses a system to detect meta-stable glitches in a signal, such as an output of latch or other storage element. The system can include a sampling circuit configured to sample an output of a storage element. The system can include a mono-shot circuit configured to monitor the output of the storage element and generate a pulse when the monitored output of the storage element differs from the sampled output. The system can include a drive circuit configured to generate a glitch signal based, at least in part, on the sampled output, and to output the glitch signal in response to the pulse from the mono-shot circuit. The system can include an error detection circuit configured to receive the sampled output from the sampling circuit and the glitch signal from the drive circuit, and to generate an error signal when the sampled output differs from the glitch signal.

A current sensor assembly can include: a coil structure having a first coil and a second coil connected in series, the coil structure configured to generate a differential magnetic field responsive to an electrical current passing through the first and second coils; a first magnetic field sensing element disposed proximate to the first coil and operable to generate a first signal responsive to the differential magnetic field passing through the first magnetic field sensing element in a first direction; a second magnetic field sensing element disposed proximate to the second coil and operable to generate a second signal responsive to the differential magnetic field passing through the second magnetic field sensing element in a second direction; and a circuit operable to subtract the first and second signals to generate a differential signal proportional to the electrical current.

This application discloses a system to detect meta-stable glitches in a signal, such as an output of latch or other storage element. The system can include a sampling circuit configured to sample an output of a storage element. The system can include a mono-shot circuit configured to monitor the output of the storage element and generate a pulse when the monitored output of the storage element differs from the sampled output. The system can include a drive circuit configured to generate a glitch signal based, at least in part, on the sampled output, and to output the glitch signal in response to the pulse from the mono-shot circuit. The system can include an error detection circuit configured to receive the sampled output from the sampling circuit and the glitch signal from the drive circuit, and to generate an error signal when the sampled output differs from the glitch signal.

An operational amplifier-based hysteresis comparator and a chip are provided. The hysteresis comparator includes: an input stage and an amplification stage. The input stage includes: a first input branch and a second input branch, where the first input branch generates a first current based on the first voltage, and the second input branch generates a second current based on the second voltage. The first current is connected with a first input terminal of the amplification stage, and the second current is connected with a second input terminal of the amplification stage. An output terminal of the amplification stage outputs a first level when the first current is greater than the second current, and outputs a second level when the first current is less than the second current. The present disclosure changes the hysteresis voltage generation mode, thereby reducing the instability caused by positive feedback.

A device for detecting an electrical overcurrent event includes a current sensor configured to generate a first sense signal representative of an absolute current value of an electrical current through an electrical conductor. The device further includes a sense unit configured to generate a second sense signal representative of a temporal change of the electrical current. The device further includes an adjustment unit configured to adjust a previously set first threshold value for the absolute current value based on the second sense signal. The device further includes a detection unit configured to detect an overcurrent event in the electrical conductor based on a comparison between the first sense signal and the adjusted first threshold value.