Apparatuses, systems and methods for regulating the output currents of a power supply at a target output current include a buck converter module operably connected to a power source and a load. A first switch couples the power source to the buck converter module during a first period of a given operating cycle, while the buck converter module stores and provides electrical power to the load. During a second period, the buck converter may discharge the electrical power stored during the first period. A current sensor senses the currents during at least one of the first period and the second period and, over the operating cycle, the switching is adjusted so the average output current equals the target output current. Adjustments to the first and second period durations result in maximum and a minimum currents symmetrically disposed about the average current provided to the load during the operating cycle.

A two-way load control system comprises a power device, such as a load control device for controlling an electrical load receiving power from an AC power source, and a controller adapted to be coupled in series between the source and the power device. The load control system may be installed without requiring any additional wires to be run, and is easily configured without the need for a computer or an advanced commissioning procedure. The power device receives both power and communication over two wires. The controller generates a phase-control voltage and transmits a forward digital message to the power device by encoding digital information in timing edges of the phase-control voltage. The power device transmits a reverse digital message to the controller via the power wiring.

A two-way load control system comprises a power device, such as a load control device for controlling an electrical load receiving power from an AC power source, and a controller adapted to be coupled in series between the source and the power device. The load control system may be installed without requiring any additional wires to be run, and is easily configured without the need for a computer or an advanced commissioning procedure. The power device receives both power and communication over two wires. The controller generates a phase-control voltage and transmits a forward digital message to the power device by encoding digital information in timing edges of the phase-control voltage. The power device transmits a reverse digital message to the controller via the power wiring.

A load driving circuit includes a switch circuit and a linear circuit connected in series. The switch circuit has a switching transistor and converts an input voltage into a first output voltage. The linear circuit has a linear device and provides a driving voltage and a driving current for driving the load. The driving circuit controls the switching transistor according to a feedback signal indicative of conducting state of the linear device.

A load driving circuit includes a switch circuit and a linear circuit connected in series. The switch circuit has a switching transistor and converts an input voltage into a first output voltage. The linear circuit has a linear device and provides a driving voltage and a driving current for driving the load. The driving circuit controls the switching transistor according to a feedback signal indicative of conducting state of the linear device.

Operating DC to DC power converters. At least some of the example embodiments are methods including: driving current through an inductance in a first on cycle of the power converter; comparing, by a comparator, a signal indicative of current through the inductance coupled to a first input of the comparator to a threshold applied to a second input of the comparator, and asserting a comparator output responsive to the signal indicative of current meeting the threshold; sampling a differential voltage across the first and second inputs, the sampling responsive to assertion of a comparator output, and the differential voltage indicative of propagation delay through the comparator; and compensating the comparator in a second on cycle for the compensation delay based on the differential voltage, the second on cycle subsequent to the first on cycle.

An LED tube lamp with overvoltage protection capability is provided. The LED tube lamp includes a lamp tube, two external connection terminals, a rectifying circuit, a filtering circuit, an LED module, and a protection circuit. The protection circuit is coupled between two input terminals of the LED module and configured to perform overvoltage protection when determining that a voltage level between the two input terminals of the LED module reaches or is higher than a predefined voltage value, wherein the protection circuit includes a diode and the predefined voltage value is in a range of about 40V to about 600V.

A solid state driver to adapt current ripple characteristics therein, at least partially based on operating characteristics of a solid state lighting device operated by the driver, is provided. The driver senses operating voltage, operating current, or a combination of operating voltage and operating current of a solid state lighting device. The driver stores pre-determined current ripple percentage settings in a data structure, for example, in a controller circuit. The driver selects and implements one of the pre-determined current ripple percentage settings based on one or more of the sensed operating characteristics of the solid state lighting device, to improve efficiency, to reduce the operating frequency, and/or to lower the operating temperature of one or more components of the driver.

A solid state driver to adapt current ripple characteristics therein, at least partially based on operating characteristics of a solid state lighting device operated by the driver, is provided. The driver senses operating voltage, operating current, or a combination of operating voltage and operating current of a solid state lighting device. The driver stores pre-determined current ripple percentage settings in a data structure, for example, in a controller circuit. The driver selects and implements one of the pre-determined current ripple percentage settings based on one or more of the sensed operating characteristics of the solid state lighting device, to improve efficiency, to reduce the operating frequency, and/or to lower the operating temperature of one or more components of the driver.

Provided is a buck-boost converting circuit including an LED current regulator and bypass switches. The buck-boost converting circuit includes switches coupled in a matrix form in order to individually control a plurality of LEDs connected in series, an LED current regulator, and a circuit capable of buck-boost conversion.