A converter configured to supply an energy consuming element during an operating phase and may charge a capacitor during a pre-charging phase prior to the operating phase. The converter may have a power factor correction circuit having the capacitor and thyristors. The converter may also have a control system configured to control the pre-charging phase. The control system may have a control unit configured to, during the operating phase, detect the state of charge of the capacitor, and generate a control signal configured to control the thyristors as a function of the state of charge of the capacitor.

A drive circuit has a control signal input for receiving a first control signal at a first circuit input, an optocoupler which is connected to the control signal input and which is adapted to generate a galvanically decoupled second control signal in accordance with the first control signal, an output circuit for controlling at least one circuit output terminal of the drive circuit in accordance with a third control signal, and an electronic control circuit comprising an energy supply, an input for receiving the second control signal, and an output for outputting the third control signal in accordance with the second control signal received at the input.

An optical emission circuit includes a power supply source and a regulation circuit coupled to control the power supply source. An optical source and a first switch are coupled in series to the power supply source. A square pulse signal source has an output coupled to a control input of the first switch. The square pulse signal source is configured to provide a square pulse signal. The regulation circuit regulates the current supplied by the power supply source according to a product of a peak current set point by a duty cycle of the square pulse signal.

A photoelectric sensor can include: a lighting element configured to generate a first optical signal, where a second optical signal is generated by reflection of the first optical signal when emitting an object; a driving circuit configured to drive the lighting element; a photoelectric conversion circuit configured to generate a first optical current in accordance with the second optical signal; and a programmable current amplifier circuit configured to sample and hold the first optical current when the lighting element is in operation, and to generate a second optical current when the lighting element is out of operation in one detection period, where the second optical current lasts for at least one working period in the detection period, and where the second optical current represents the first optical current.

A photoelectric sensor can include: a lighting element configured to generate a first optical signal, where a second optical signal is generated by reflection of the first optical signal when emitting an object; a driving circuit configured to drive the lighting element; a photoelectric conversion circuit configured to generate a first optical current in accordance with the second optical signal; and a programmable current amplifier circuit configured to sample and hold the first optical current when the lighting element is in operation, and to generate a second optical current when the lighting element is out of operation in one detection period, where the second optical current lasts for at least one working period in the detection period, and where the second optical current represents the first optical current.

A microcontroller based multifunctional electronic switch using a detection circuit design to convert external motion signals into message carrying sensing signals readable to the microcontroller. Based on the time length of sensing signals and the format of the sensing signals received in a preset instant period of time the microcontroller through the operation of its software program codes written in the OTPROM is able to recognize the working modes chosen by the external signal generating user and thereby selecting the appropriate loops of subroutine for execution. The system and method of the present invention may simultaneously be applicable to detection circuit design using infrared ray sensor, electrostatic induction sensor, conduction based touch sensor or push button sensor for performing multifunction such as controlling the on/off switch performance, the diming or speed control and the delay timer management within the capacity of a single lighting device or an electrical appliance.

A microcontroller based multifunctional electronic switch using a detection circuit design to convert external motion signals into message carrying sensing signals readable to the microcontroller. Based on the time length of sensing signals and the format of the sensing signals received in a preset instant period of time the microcontroller through the operation of its software program codes written in the OTPROM is able to recognize the working modes chosen by the external signal generating user and thereby selecting the appropriate loops of subroutine for execution. The system and method of the present invention may simultaneously be applicable to detection circuit design using infrared ray sensor, electrostatic induction sensor, conduction based touch sensor or push button sensor for performing multifunction such as controlling the on/off switch performance, the diming or speed control and the delay timer management within the capacity of a single lighting device or an electrical appliance.

Devices, methods and techniques are disclosed to interrupt a fault current in a high-voltage direct-current circuit. In one example aspect, a device includes a mechanical switch including a pair of contacts configured to be positioned apart upon activation of the circuit breaker, and a photoconductive component connected in parallel with the mechanical switch. The photoconductive component is configured to establish a current upon activation of the circuit breaker. The photoconductive component comprises a crystalline material positioned to receive a pulsed light signal from a laser light source, and a pair of electrodes coupled to the crystalline material and configured to allow an electric field to be established across the crystalline material to generate the current.

A four-terminal circuit element is described that includes a photonic core inside of the circuit element that uses a wide bandgap semiconductor material that exhibits photoconductivity and allows current flow through the material in response to the light that is incident on the wide bandgap material. The four-terminal circuit element can be configured based on various hardware structures using a single piece or multiple pieces or layers of a wide bandgap semiconductor material to achieve various designed electrical properties such as high switching voltages by using the photoconductive feature beyond the breakdown voltages of semiconductor devices or circuits operated based on electrical bias or control designs. The photonic core aspect of the four-terminal circuit element provides unique features that enable versatile circuit applications to either replace the semiconductor transistor-based circuit elements or semiconductor diode-based circuit elements.

A four-terminal circuit element is described that includes a photonic core inside of the circuit element that uses a wide bandgap semiconductor material that exhibits photoconductivity and allows current flow through the material in response to the light that is incident on the wide bandgap material. The four-terminal circuit element can be configured based on various hardware structures using a single piece or multiple pieces or layers of a wide bandgap semiconductor material to achieve various designed electrical properties such as high switching voltages by using the photoconductive feature beyond the breakdown voltages of semiconductor devices or circuits operated based on electrical bias or control designs. The photonic core aspect of the four-terminal circuit element provides unique features that enable versatile circuit applications to either replace the semiconductor transistor-based circuit elements or semiconductor diode-based circuit elements.