A circuit comprises an optical coupling including an illuminator optically coupled to an optical sensor to output a voltage from the optical sensor based on intensity of illumination from the illuminator. The circuit includes a voltage input node with a resistance connected in series between the voltage input and a Zener diode. A method includes powering an illuminator with current from a first voltage input node. The method includes sensing illumination level in illumination from the illuminator with a sensor and outputting output proportionate to illumination sensed by the sensor indicative of voltage detected at the voltage input node. The method can include limiting current between the voltage input node and the illuminator.

A method for detecting error on an input/output (IO) pin of an integrated circuit includes using the input/output pin of the integrated circuit in a first mode by receiving or sending a first value as analog data or digital data. The input/output pin is toggled in a test mode after each instance of using the input/output pin in the first mode. The test mode includes providing a second value disparate from the first value during a set time after using the input/output pin in the first mode, receiving back during the set time a resulting value based on providing the second value, measuring the resulting value, and identifying an error on the input/output pin of the integrated circuit based on the measured resulting value.

The invention discloses a method for controlling the time sharing starting of electronic ballasts and a delayed-started electronic ballast. According to the method, the electronic ballasts are delayed-started after being energized, and delay time for the delayed starting of the electronic ballasts is a random number acquired based on the temperature of the ballasts. The delayed-started electronic ballast includes an electronic ballast body and a delay switch. After the adoption of the technical scheme of the invention, a delayer with the delay time set by virtue of random numbers corresponding to different environmental temperature is additionally arranged in the ballast, and multiple ballasts connected in parallel in a circuit can be started at different time points after different delay time under the control of the same control switch, which remarkably reduces current impact on a power grid and reduces a voltage drop condition.

A circuit comprises an optical coupling including an illuminator optically coupled to an optical sensor to output a voltage from the optical sensor based on intensity of illumination from the illuminator. The circuit includes a voltage input node with a resistance connected in series between the voltage input and a Zener diode. A method includes powering an illuminator with current from a first voltage input node. The method includes sensing illumination level in illumination from the illuminator with a sensor and outputting output proportionate to illumination sensed by the sensor indicative of voltage detected at the voltage input node. The method can include limiting current between the voltage input node and the illuminator.

A processor starts output of a drive signal prior to output of a control signal. The processor determines a fault related to the drive signal based on a detection signal outputted from a detection circuit. In a case where a fault related to the drive signal is not detected, the processor starts output of the control signal. In a case where a fault related to the drive signal is detected, the processor stops output of the drive signal.

A method for detecting error on an input/output (IO) pin of an integrated circuit includes using the input/output pin of the integrated circuit in a first mode by receiving or sending a first value as analog data or digital data. The input/output pin is toggled in a test mode after each instance of using the input/output pin in the first mode. The test mode includes providing a second value disparate from the first value during a set time after using the input/output pin in the first mode, receiving back during the set time a resulting value based on providing the second value, measuring the resulting value, and identifying an error on the input/output pin of the integrated circuit based on the measured resulting value.

A processor starts output of a drive signal prior to output of a control signal. The processor determines a fault related to the drive signal based on a detection signal outputted from a detection circuit. In a case where a fault related to the drive signal is not detected, the processor starts output of the control signal. In a case where a fault related to the drive signal is detected, the processor stops output of the drive signal.

A luminaire otherwise lacking connectivity is provided hereby with an isolated method for connecting to a lighting control system. The luminaire comprises an NFC-equipped LED driver having a first antenna. A digital control device with a second antenna is permanently or semi-permanently mounted in or on the luminaire wherein the second antenna is positioned in operable proximity with the first antenna. The digital control device includes a first transceiver in communication with the external device and a first controller to receive and store device configuration data from the external device in volatile memory associated with a second transceiver linked to the first antenna. A controller associated with the LED driver selectively obtains the device configuration data from the volatile memory via the NFC field, and generates output current reference signals for regulating the output current from the LED driver, said reference signals corresponding to the device configuration data.

A protection system for an LED driver includes a voltage rail, an input voltage source, and a surge protector connected between the input voltage source and the voltage rail. The voltage change sensing block detects a change in a voltage associated with the input voltage source. The protection system further includes a voltage sensing block connected to the voltage change sensor. A half-bridge switching circuit may include a switch controller, a first switching element, and a second switching element. The switch controller controls an operating state of each of the first switching element and the second switching element. A reset block disables at least one of the switch controller, the first sensing element, and the second switching element, responsive to a control signal associated with at least one of the voltage change sensing block and the voltage sensing block.

A light emitting diode driving chip includes: a current regulating circuit arranged to selectively outputting four currents to four pins respectively; a current control circuit coupled to the current regulating circuit and a fifth pin, arranged to receive an adjusting signal at the fifth pin to control the four currents; a feedback voltage control circuit arranged to output a feedback voltage to a sixth pin according to a first specific voltage selected from four voltages corresponding to the four pins; and a protection circuit arranged to determine whether a voltage difference between a second specific voltage selected from the four voltages and the first specific voltage is larger than a threshold value. If the first specific voltage is larger than the threshold value, the protection circuit controls the current regulating circuit to stop conducting current to a specific pin corresponding to the first specific voltage.