A light-emitting diode (LED) lighting device has an LED and a power supply including an inductor coupled to the LED. A cathode of the LED is coupled to the inductor opposite an anode of the LED. The inductor is coupled for receiving a first power signal. A transistor includes a conduction terminal coupled to the inductor to enable current through the inductor. A current from the first power signal is switched to generate a second power signal. A first diode includes an anode coupled to the inductor opposite the cathode of the LED. A controller includes a first terminal coupled to a cathode of the first diode and a second terminal coupled to a control terminal of the transistor. A zener diode is coupled to the first terminal of the controller. A capacitor is coupled between the first diode and inductor. A second diode is coupled to the first diode.

Programmable drivers (or power supplies) for solid state light sources are disclosed, on which output regulation is improved to expand the dimming range to 1% and reduce and/or remove flicker. Additional fault conditions are set up to avoid latching, and thus provide for a controllable restart feature. Such drivers include an isolated half bridge resonant converter with an improved control approach designed to regulate very low current though primary side in a feed-forward loop. Such drivers include both digital and analog loops that improve the performance in steady state and/or during transients, particularly for a lighting load, in comparison to a single full digital control.

A discharge lamp drive device includes a discharge lamp driver adapted to supply a drive current to a discharge lamp, a control section adapted to control the discharge lamp driver, and a storage section adapted to store a plurality of drive patterns of the drive current. Each of the drive patterns has a plurality of drive parameters. The plurality of drive patterns includes a first drive pattern and a second drive pattern different from each other in a value of at least one of the plurality of drive parameters. The control section is configured to execute the first drive pattern and the second drive pattern in accordance with at least one of accumulated lighting time of the discharge lamp and an individual of the discharge lamp in a case in which an inter-electrode voltage of the discharge lamp is at a predetermined voltage value.

The invention provides a multi-channel independent control circuit of lighting power supply, including a power supply control circuit, a transformer, a main current rectifier circuit, a feedback circuit and a main current output circuit, and also including one or more secondary side units. The secondary side unit includes secondary windings, secondary side rectifier circuit, secondary side output circuit, switching circuit, detector and logic control circuit, the secondary side winding is couple to the primary winding, the secondary side rectifier circuit and the secondary side output circuit are sequentially connected in parallel across the loop of the secondary winding, the detector is disposed in the secondary side output circuit and an output end of the detector is connected to an input end of the switching circuit through the logic control circuit. An output end of the switching circuit is connected to the secondary side output circuit. The invention relates to the multi-channel independent control circuit of lighting power supply, realizing independent and normal operation of multiple lighting apparatus or devices, and improving the flexibility, reliability and safety of the entire lighting system.

A load current adjusting circuit can include: a counter configured to generate first and second digital signals in accordance with a pulse signal, where a numerical relationship between the first and second digital signals is determined in accordance with a duty cycle of the pulse signal; and an adjusting circuit configured to adjust a load current to vary along with the duty cycle of the pulse signal in accordance with the first and second digital signals.

A load current adjusting circuit can include: a counter configured to generate first and second digital signals in accordance with a pulse signal, where a numerical relationship between the first and second digital signals is determined in accordance with a duty cycle of the pulse signal; and an adjusting circuit configured to adjust a load current to vary along with the duty cycle of the pulse signal in accordance with the first and second digital signals.

Converters (1) comprise switches (14) for in response to control signals controlling amplitudes of converter output signals and comprise control loops for in response to detections of the amplitudes of the converter output signals producing the control signals. The control loops comprise circuits (21-23) for in response to simple detections of the amplitudes counting a first number of first time-intervals for which the amplitudes are above or below reference amplitudes, for transforming counting results into the control signals having control values, and for in response to the first number of first time-intervals being equal to/larger than a reference number overruling the control values and producing control signals having first or second limit values. Complex detections of the amplitudes are no longer necessary. Simple detectors (3, 4) may detect the amplitudes of the output signals and amplitudes or phases of input signals or rectified versions thereof and produce binary signals destined for binary inputs of micro-controllers (2) comprising the circuits (21-23).

A discharge lamp drive device includes a discharge lamp driver adapted to supply a drive current to a discharge lamp, a control section adapted to control the discharge lamp driver, and a storage section adapted to store a plurality of drive patterns of the drive current. Each of the drive patterns has a plurality of drive parameters. The plurality of drive patterns includes a first drive pattern and a second drive pattern different from each other in a value of at least one of the plurality of drive parameters. The control section is configured to execute the first drive pattern and the second drive pattern in accordance with at least one of accumulated lighting time of the discharge lamp and an individual of the discharge lamp in a case in which an inter-electrode voltage of the discharge lamp is at a predetermined voltage value.

A light source device includes: a lighting circuit that includes a direct-current power source, a transformer, and a switching element, and generates electromotive force in a secondary winding of the transformer in accordance with switching of an ON state and an OFF state of the switching element; a dielectric barrier discharge lamp that is connected to the secondary winding of the transformer, and a controller that performs ON/OFF control on the switching element. The controller performs: a starting mode for repeating ON/OFF control on the switching element at a predetermined frequency at a time of starting; and a steady-state operation mode for alternately performing first control and second control after the dielectric barrier discharge lamp has been started, the first control being performed to repeat ON/OFF control on the switching element at the predetermined frequency, the second control being performed to maintain the switching element in the OFF state.

A dimmable ballast circuit for a compact fluorescent lamp controls the intensity of a lamp tube in response to a phase-control voltage received from a dimmer switch. The ballast circuit comprises a phase-control-to-DC converter circuit that receives the phase-control voltage, which is characterized by a duty cycle defining a target intensity of the lamp tube, and generates a DC voltage representative of the duty cycle of the phase-control voltage. Changes in the duty cycle of the phase-control voltage that are below a threshold amount are filtered out by the converter circuit, while intentional changes in the duty cycle of the phase-control voltage are reflected in changes in the target intensity level and thereby the intensity level of the lamp tube.