In a power converter having a regulator and charge pump, both of which operate in plural modes, a controller receives information indicative of the power converter's operation and, based at least in part on said information, causes transitions between regulator modes and transitions between charge-pump modes.

An electronic circuit and a method are disclosed. The electronic circuit includes an LED circuit, wherein the LED circuit (1) includes: an input (11, 12) configured to receive an input voltage (V.sub.IN); a drive circuit (2A) connected to the input (11, 12); and an LED module (3A) connected to the drive circuit (2A) and comprising an LED string (4.sub.1) with at least one LED. The drive circuit (2A) is configured to monitor the LED module (3A) for the occurrence of an LED short in the LED string (4.sub.1) and to change from a normal mode to a defect mode upon detection of the LED short, and the drive circuit (2A) is configured, in the defect mode, to operate the LED string (4.sub.1) in at least one defect cycle that includes deactivating the LED string (4.sub.1) for a deactivation period, activating the LED string for an activation period, and checking for the persistence of the LED short in the activation period.

A power restoration system comprising a feeder, a plurality of power sources available to provide power to the feeder, a plurality of normally closed reclosing devices electrically coupled along the feeder, at least one normally open recloser electrically coupled to the feeder, and a plurality of normally closed switches electrically coupled along the feeder between each adjacent pairs of normally closed reclosing devices. Each switch is assigned a position code having a value for each of the plurality of power sources that determines when the switch will open in response to the fault current and which power source the switch is currently receiving power from, where timing control between the reclosing devices and the switches allows the switch to be selectively opened to isolate the fault within a single feeder section between each pair of adjacent switches or between each switch and a reclosing device.

A system for an electrical power distribution network includes an electrical apparatus configured to monitor or control one or more aspects of the electrical power distribution network, the electrical apparatus including a contact switch configured to open and close. The system also includes an input apparatus. The input apparatus includes an impedance module; and an input interface electrically connected to the impedance module and to the contact switch of the electrical apparatus. The input interface is configured to have one of a plurality of input impedances, the plurality of input impedances include at least a first input impedance and a second input impedance that is lower than the first input impedance, and the input interface has the second input impedance when the contact switch of the electrical apparatus is open. The input apparatus may include a plurality of leakage current detection modules.

A controller for a secondary side of a switched mode power supply. A thermistor and an LED of an optocoupler are connected in parallel with each other between a voltage-supply-pin and a STOP pin of the controller. A reference-source provides a reference-signal between the STOP pin and the voltage-supply-pin. The STOP pin receives a temperature-measurement-signal from the thermistor, wherein the temperature-measurement-signal is representative of the resistance of the thermistor. The controller also includes an OTP-comparator that compares: (i) the temperature-measurement-signal; with (ii) a threshold-level, and provides an OTP-signal that is representative of whether or not the temperature-measurement-signal at the STOP pin crosses the threshold-level; and a switchable-current-source that selectively provides a bias-current to the STOP pin based on the OTP-signal, wherein the bias-current causes the LED to emit a light-signal that is representative of a fault to an associated photo-detector.

An overvoltage recovery circuit (ORC), a controller for an HVAC system and an HVAC system are disclosed herein. In one embodiment, the ORC includes: (1) a first supply voltage terminal connected to a first voltage supply, (2) a second supply voltage terminal connected to a second voltage supply, (3) interruption circuitry including a switch and a trip terminal connected to the second supply voltage terminal and (4) detection circuitry connected to the first supply voltage terminal and the switch of the interruption circuitry, the detection circuitry configured to operate the switch in response to an overvoltage condition at the first supply voltage terminal.

Detection of faults in an electrical power distribution network that includes measuring current flowing through a recloser in a feeder line, detecting a fault current indicating a fault is present in the feeder line, and opening a switch in the recloser in response to detecting the fault current. A first pulse having a first pulse duration time is generated, and the current flow in the recloser during the first pulse duration time is analyzed. A second pulse having a second duration time that is longer than the first pulse duration time is generated if it is determined that no fault current exists during the first pulse duration time, and the system voltages and the current flowing through the recloser after the second pulse duration time is analyzed for the presence of the fault.

An electronic protection circuit includes a resettable fuse such as a positive temperature coefficient (PTC) thermistor or polymer PTC device. The resettable fuse enters a high-resistance tripped state in response to an overcurrent condition. One or more electrically controllable switches are placed in series with the resettable fuse. A monitoring and control circuit monitors voltage across the resettable fuse and to opens the switches when the voltage is outside of a predetermined range. The switches can remain open after the overcurrent event is resolved in order to allow the resettable fuse time to reset.

An over-current protection apparatus constituted of: a transistor disposed on a substrate; a first thermal sense device arranged to sense a temperature reflective of a junction temperature of the transistor; a second thermal sense device arranged to sense a temperature reflective of a temperature of a casing surrounding the substrate; and a control circuitry, arranged to alternately: responsive to the sensed temperature by the first thermal sense device and the sensed temperature of the second thermal sense device being indicative that the temperature difference between the transistor junction and the substrate casing is greater than a predetermined value, switch off the transistor; and responsive to the sensed temperature by the first thermal sense device and the sensed temperature by the second thermal sense device being indicative that the temperature difference between the transistor junction and the substrate casing is not greater than the predetermined value, switch on the transistor.

The redundant power supply device includes a power output port, a converter, a comparator unit and an output protection switch. The output protection switch is electrically connected between an output terminal of the converter and the power output port, and the comparator unit compares the voltage across the output protection switch and controls the output protection switch accordingly. The redundant power supply device has a control module that performs a protection control method. When the voltage of the power output port is higher than a preset voltage value and the output current is lower than a preset current value, the control module outputs a short turn-off signal to the enable terminal of the comparator unit, preventing the comparator unit from failing to perform the output protection as designed due to external abnormal slow rising voltage, and ensuring the redundant power supply unit operates normally.