Systems and methods for electronics systems are provided herein. An electronics system may comprise a heating circuit and a fault detection system. The heating circuit may include a heating element. The fault detection system may include a current-to-voltage converter, a voltage level detector, and a controllable switch connected in series with the heating element, the controllable switch in electronic communication with the voltage level detector. A fault may be detected in response to a secondary voltage being greater than a threshold value.

Distance protection for electric power systems disclosed herein uses an operating signal and a sequence polarizing signal made up of a supervised sequence current and a supervised sequence voltage. The polarizing signal may be determined based on the fault type and may be weighted toward sequence currents or sequence voltages depending on the power system conditions. For phase-to-ground faults, the sequence currents may include negative-sequence and zero-sequence currents. For phase-to-phase faults, the sequence currents may include negative-sequence currents. The current portion of the sequence polarizing signal may be weighted based on detection of insufficient negative-sequence current magnitude, standing unbalance, current transformer saturation, open pole, three-phase fault, and the like. The distance elements described herein provides improved protection during real-world power system conditions and changes.

Distance protection for electric power systems disclosed herein uses an operating signal and a sequence polarizing signal made up of a supervised sequence current and a supervised sequence voltage. The polarizing signal may be determined based on the fault type and may be weighted toward sequence currents or sequence voltages depending on the power system conditions. For phase-to-ground faults, the sequence currents may include negative-sequence and zero-sequence currents. For phase-to-phase faults, the sequence currents may include negative-sequence currents. The current portion of the sequence polarizing signal may be weighted based on detection of insufficient negative-sequence current magnitude, standing unbalance, current transformer saturation, open pole, three-phase fault, and the like. The distance elements described herein provides improved protection during real-world power system conditions and changes.

A USB Type-C/Power Delivery controller chip includes a first pin for receiving a first voltage, a second pin for receiving a second voltage, and a third pin for coupling to the CC pin of a USB connector. The USB controller chip includes a VCONN power supply circuit having a blocking field effect transistor (BFET) coupled in series with a hot-swap field FET (HSFET) between the first and third pins, and first and second Zener diodes coupled anode-to-anode between the HSFET's source and gate. A cable detection circuit includes a BFET coupled between the second and third pins, and a Zener diode coupled between the BFET's gate and a lower rail. A power delivery physical layer circuit includes a receiver and a transmitter, each coupled to the third pin through a respective BFET, the respective BFETs each having a Zener diode coupled between respective gates and the lower rail.

A USB Type-C/Power Delivery controller chip includes a first pin for receiving a first voltage, a second pin for receiving a second voltage, and a third pin for coupling to the CC pin of a USB connector. The USB controller chip includes a VCONN power supply circuit having a blocking field effect transistor (BFET) coupled in series with a hot-swap field FET (HSFET) between the first and third pins, and first and second Zener diodes coupled anode-to-anode between the HSFET's source and gate. A cable detection circuit includes a BFET coupled between the second and third pins, and a Zener diode coupled between the BFET's gate and a lower rail. A power delivery physical layer circuit includes a receiver and a transmitter, each coupled to the third pin through a respective BFET, the respective BFETs each having a Zener diode coupled between respective gates and the lower rail.

A leakage current protection device with automatic reset after power outage includes a switch, a power supply module, a leakage current detection module, a self-testing module, a drive control module, and a first reset module. The drive control module drives the switch based on a leakage current signal from the leakage current detection module and/or a self-test fault signal from the self-testing module. The first reset module functions to automatically set the leakage current protection device in a connected state when power resumes after an outage. Another leakage current protection device with manual reset after power outage includes similar components above and also a second reset module, which functions to automatically set the leakage current protection device in a disconnected state when power resumes after an outage; the device can then be manually reset using a reset switch. These two devices can suit different needs of different electrical appliances.

The present disclosure pertains to detection of abnormal, risky, or abberant conditions in a power distribution network and to corresponding trip signals being used to trip open devices such as reclosers upstream of where the abnormal condition is detected. Detection of a missing broadband over power-line signal or of an open circuit between phases of a power distribution circuit may prevent severed conductors from causing a ground fault, therefore avoiding the possibility of fire and dangerous conditions.

An over-voltage protection circuit includes an over-voltage detection circuit, a voltage generator and a switch for providing over-voltage protection between two pins of a USB Type-C port. The over-voltage detection circuit provides an over-voltage signal according to the level of the second pin. The switch includes a first end coupled to the first pin, a second end coupled to the second pin and a control end coupled to a control signal. When the over-voltage signal does not indicate an over-voltage occurrence at the second pin, the voltage generator provides the control signal having a first level for operating the switch in a first region. When the over-voltage signal indicates an over-voltage occurrence at the second pin, the voltage generator adjusts the control signal to a second level for cutting off the switch. The switch operates in a second region after the over-voltage occurrence and before the switch is cut off.

An electrical apparatus configured to electrically connect to a multi-phase alternating current (AC) electrical power distribution network includes: an input electrical network including: a plurality of input nodes, each configured to electrically connect to one phase of the multi-phase AC electrical power distribution network; at least one non-linear electronic component electrically connected to the input electrical network; an impedance network electrically connected between the input electrical network and ground; and a control system configured to: access a voltage signal that represents a voltage over time at the input electrical network; determine a frequency content of the voltage signal; determine a property of the frequency content; and determine whether an input current performance condition exists in the electrical apparatus based the property of the frequency content.

A potential difference early-warning circuit, comprising: a sensing resistor (R2), one end of the sensing resistor being connected to a signal ground (PCB GND); a first MOS (M1), a drain of the first MOS being connected to the other end of the sensing resistor (R2), and a source of the first MOS (M1) being connected to a safety ground (GND); an operational amplifier (U1A), a positive input end of the operational amplifier being connected to one end of the sensing resistor (R2), and a negative input end of the operational amplifier (U1A) being connected to the other end of the sensing resistor (R2); a second MOS (M2), a gate of the second MOS (M2) being connected to an output end of the operational amplifier (U1A), and a source of the second MOS (M2) being connected to the signal ground; and a controller, a first input end of the controller being connected to the drain of the second MOS (M2), and an output end of the controller being connected to the gate of the second MOS (M2); wherein the operational amplifier (U1A) is configured to transmit a corresponding level to the second MOS (M2) according to the magnitude of the potential difference between the signal ground (PCB GND) and the safety ground (GND), so as to control the second MOS (M2) to be turned on or turned off, so that the controller receives the corresponding level through the first input end, and then the controller controls the first MOS to be turned on or turned off according to the received level.