A control method of a switching circuit, a control circuit of the switching circuit, and the switching circuit are provided. The switching circuit includes an inductor or a transformer. An operational amplification is performed on an output feedback voltage and a first reference voltage of the switching circuit to obtain a compensation voltage. The compensation voltage controls an on-time of a main switch of the switching circuit. When the current of the inductor or the transformer drops to a threshold, after a time, the main switch is switched from off to on, and the output feedback voltage controls the time. When the output feedback voltage is higher than a first threshold voltage, the compensation voltage is pulled down. When the output feedback voltage is lower than a second threshold voltage, the compensation voltage is pulled up.

An apparatus, system and method of controlling the supply of DC current from a power source to an electrical load provides for a protective circuit that senses the characteristics of the connected load prior to permitting the enablement of a switch connecting the supply and the load. A voltage arising from applying a constant current to the load during a time period is compared with a predetermined threshold determined by the intended capacity of the switch so that, when closed, the current through the switch is compatible with the switch. The protective circuit may be used in conjunction with semiconductor switches, electromechanical contactors or relays. A plurality of such devices may be incorporated in an enclosure and controlled by logic so as to manage the supply of power from a power source to a plurality of electrical loads having differing power requirements.

The electronics comprises a load circuit, a power supply circuit having a rechargeable electrical energy storer, and a protection circuit. An input of the power supply circuit is adapted to be electrically connected with an external energy supply. Both the power supply circuit and the protection circuit have at least two operating modes. Additionally, the protection circuit is adapted in the first operating mode to monitor the cell voltage applied on the circuit input to determine whether its voltage level has exceeded a predetermined maximum value and, in given cases, automatically to deactivate the operating mode.

Disclosed is a power failure detection device and method capable of issuing a power failure alert early. The device includes a voltage reduction circuit, a detection voltage generating circuit, a detection circuit, and a transmitting circuit. The voltage reduction circuit is or includes at least one active electronic component, and generates an output voltage according to an input voltage higher than the output voltage. The detection voltage generating circuit is coupled between the voltage reduction circuit and a low voltage terminal, and generates a detection voltage according to the output voltage that is between the output voltage and the voltage of the low voltage terminal. The detection circuit generates a detection result according to the detection voltage and a trigger voltage. The transmitting circuit sends a power failure alert to a far-end device on condition that the detection result indicates that the detection voltage is lower than the trigger voltage.

A power source combination circuit has a combination circuit and a controller. The combination circuit includes a first power source, a first field-effect transistor, a second power source, and a second field-effect transistor. The controller is configured to control the combination circuit to supply power to a load circuit, obtain a first input voltage, a second input voltage, and a third input voltage, and diagnose, based on the obtained voltages, whether the combination circuit is in a normal state or an abnormal state. The first input voltage is an input side voltage of the first field-effect transistor, the second input voltage is an input side voltage of the second field-effect transistor, and the third input voltage is a voltage at a power source input end of the load circuit.

A method for in situ threshold voltage determination of a semiconductor device includes sourcing a current to a first terminal of the semiconductor device. A gate terminal of the semiconductor device is driven with a plurality of gate levels. Each gate level includes one of a plurality of different gate voltages. A transistor voltage is measured between the first terminal and a second terminal of the semiconductor device during each gate level. The respective gate voltage is stored in response to the semiconductor device voltage transitioning past a voltage limit. A temperature dependent threshold voltage of the semiconductor device is estimated for a first measured temperature measured during the storing of the stored gate voltage from a previously stored gate voltage and a second measure temperature.

In accordance with at least one aspect of this disclosure, a system can include a positive input line configured to connect between a voltage input and a load, and a negative input line configured to connect between the voltage input and the load. A logic module can be operatively connected to and/or configured to detect a fault (e.g., a short circuit) in either of the positive input line or the negative input line 104 between the voltage input and the load.

Various examples are directed to a solar power electrolyzer system comprising a first electrolyzer stack, a second electrolyzer stack, a first converter and a first converter controller. The first electrolyzer stack may be electrically coupled in series with a photovoltaic array. The first converter may be electrically coupled in series with the first electrolyzer stack and electrically coupled in series with the photovoltaic array. The second electrolyzer stack electrically may be coupled at an output of the first converter. The first converter controller may be configured to control a current gain of the first converter.

The present application provides a synchronous rectification circuit, which adopts a multiplexer that selectively inputs a first reference signal or a second reference signal to a comparator by coupling the first and second reference signal. A comparing signal is generated to a switch element by comparing a switch input signal. Hereby, the switch element is under control for synchronous rectification.

System and method for controlling one or more light emitting diodes. For example, the system for controlling one or more light emitting diodes includes a current generator configured to generate a first current flowing through one or more light emitting diodes. The one or more light emitting diodes are configured to receive a rectified voltage generated by a rectifying bridge coupled to a TRIAC dimmer. Additionally, the system includes a bleeder configured to receive the rectified voltage, and a controller configured to receive a sensing voltage from the current generator and output a control signal to the bleeder. The sensing voltage indicates a magnitude of the first current.