Abstract: A system and method control an amount of power delivered by a power converter (220) to a solid state lighting load (240). It is determined whether a dimmer (204) is present between a voltage source (201) and the power converter (220) based on a rectified input voltage from the voltage source. When the dimmer is determined to be present, an operating point of the power converter is adjusted to increase the amount of power delivered by the power converter to the solid state lighting load by a compensation amount, so that the increased amount of power is equal to an amount of power delivered by the power converter when the dimmer is not present.

Abstract: A device for controlling levels of light output by a solid state lighting load at low dimming levels includes a bleed circuit connected in parallel with the solid state lighting load. The bleed circuit includes a resistor and a transistor connected in series, the transistor being configured to turn on and off in accordance with a duty cycle of a digital control signal when a dimming level set by a dimmer is less than a predetermined first threshold, decreasing an effective resistance of the bleed circuit as the dimming level decreases.

Abstract: A method is provided for detecting and correcting improper operation of a lighting system including a solid state lighting load. The method includes detecting first and second values of a phase angle of a dimmer connected to a power converter driving the solid state lighting load, the first and second values corresponding to consecutive half cycles of an input mains voltage signal, and determining a difference between the first and second values. When the difference is greater than a difference threshold, indicating asymmetric waveforms of the input mains voltage signal, a selected corrective action is implemented.

Abstract: A device for controlling levels of light output by a solid state lighting load at low dimming levels includes a bleed circuit connected in parallel with the solid state lighting load. The bleed circuit includes a resistor and a transistor connected in series, the transistor being configured to turn on and off in accordance with a duty cycle of a digital control signal when a dimming level set by a dimmer is less than a predetermined first threshold, decreasing an effective resistance of the bleed circuit as the dimming level decreases.

Abstract: A system for controlling a level of light output by a solid state lighting load controlled by a dimmer includes a phase angle detector and a power converter. The phase angle detector is configured to detect a phase angle of the dimmer based on a rectified voltage from the dimmer and to determine a power control signal based on comparison of the detected phase angle with a predetermined first threshold. The power converter is configured to provide an output voltage to the solid state lighting load, the power converter operating in an open loop mode based on the rectified voltage from the dimmer when the detected phase angle is greater than the first threshold, and operating in a closed loop mode based on the rectified voltage from the dimmer and the determined power control signal from the detection circuit when the detected phase angle is less than the first threshold.

Abstract: A device for controlling levels of light output by a solid state lighting load at low dimming levels includes a bleed circuit connected in parallel with the solid state lighting load. The bleed circuit includes a resistor and a transistor connected in series, the transistor being configured to turn on and off in accordance with a duty cycle of a digital control signal when a dimming level set by a dimmer is less than a predetermined first threshold, decreasing an effective resistance of the bleed circuit as the dimming level decreases.

Abstract: Disclosed are devices and related methods for optimally extending the range of light output of solid-state light sources, particularly at minimum light levels, through a power converter that includes a phase detector, a processing unit and a switch. The phase detector is configured to receive a voltage signal and to detect rising edges of waveforms of the voltage signal. The processing unit is configured to initiate a predetermined shutdown period in response to each detected rising edge. The switch is configured to provide a control signal that deactivates the power converter during the shutdown period, preventing the power converter from providing power to the solid state light unit during the shutdown period.

Abstract: A method is provided for controlling a power converter (220) to provide a uniform dimming range to a solid state lighting load (240) independent of a type of dimmer. The method includes detecting maximum and minimum phase angles of a dimmer (204) connected to the power converter (220) during operation of the solid state lighting load (240), and dynamically adjusting an output power of the power converter based on the detected maximum and minimum phase angles of the dimmer. The adjusted output power of the power converter adjusts a high end level of light output by the solid state lighting load at the maximum phase angle to match a predetermined high end value and adjusts a low end level of light output by the solid state lighting load at the minimum phase angle to match a predetermined low end value.

Abstract: A device for detecting a dimmer phase angle set by operation of a dimmer for a solid state lighting load includes a processor having a digital input, a first diode connected between the digital input and a voltage source and a second diode connected between the digital input and ground. The device further includes a first capacitor connected between the digital input and a detection node, a second capacitor connected between the detection node and ground, and a resistance connected between the detection node and a rectified voltage node, which receives a rectified voltage from the dimmer. The processor is configured to sample digital pulses at the digital input based on the rectified voltage and to identify the dimmer phase angle based on lengths of the sampled digital pulses.

Abstract: A lighting apparatus (100) includes one or more first LEDs (202) for generating a first spectrum of radiation (503), and one or more second LEDs (204) for generating a second different spectrum radiation (505). The first and second LEDs are electrically connected in series between a first node (516A) and a second node (516B), between which a series current (550) flows with the application of an operating voltage (516) across the nodes. A controllable current path (518) is connected in parallel with one or both of the first and second LEDs so as to at least partially divert the series current, such that a first current (552) through the first LED(s) and a second current (554) through the second LED(s) are different. Such current diversion techniques may be employed to compensate for shifts in color or color temperature of generated light during thermal transients, due to different temperature-dependent current-to-flux relationships for different types of LEDs.

Abstract: A system and method control an amount of power delivered by a power converter (220) to a solid state lighting load (240). It is determined whether a dimmer (204) is present between a voltage source (201) and the power converter (220) based on a rectified input voltage from the voltage source. When the dimmer is determined to be present, an operating point of the power converter is adjusted to increase the amount of power delivered by the power converter to the solid state lighting load by a compensation amount, so that the increased amount of power is equal to an amount of power delivered by the power converter when the dimmer is not present.

Abstract: A system for controlling a level of light output by a solid state lighting load controlled by a dimmer includes a phase angle detector and a power converter. The phase angle detector is configured to detect a phase angle of the dimmer based on a rectified voltage from the dimmer and to determine a power control signal based on comparison of the detected phase angle with a predetermined first threshold. The power converter is configured to provide an output voltage to the solid state lighting load, the power converter operating in an open loop mode based on the rectified voltage from the dimmer when the detected phase angle is greater than the first threshold, and operating in a closed loop mode based on the rectified voltage from the dimmer and the determined power control signal from the detection circuit when the detected phase angle is less than the first threshold.

Abstract: A device for controlling levels of light output by a solid state lighting load at low dimming levels includes a bleed circuit connected in parallel with the solid state lighting load. The bleed circuit includes a resistor and a transistor connected in series, the transistor being configured to turn on and off in accordance with a duty cycle of a digital control signal when a dimming level set by a dimmer is less than a predetermined first threshold, decreasing an effective resistance of the bleed circuit as the dimming level decreases.

Abstract: A method is provided for detecting and correcting improper operation of a lighting system including a solid state lighting load. The method includes detecting first and second values of a phase angle of a dimmer connected to a power converter driving the solid state lighting load, the first and second values corresponding to consecutive half cycles of an input mains voltage signal, and determining a difference between the first and second values. When the difference is greater than a difference threshold, indicating asymmetric waveforms of the input mains voltage signal, a selected corrective action is implemented.

Abstract: Lighting apparatus and methods employing LED light sources are described. The LED light sources are integrated with other components in the form of a luminaire or other general purpose lighting structure. Some of the lighting structures are formed as Parabolic Aluminum Reflector (PAR) luminaires, allowing them to be inserted into conventional sockets. The lighting structures display beneficial operating characteristics, such as efficient operation, high thermal dissipation, high output, and good color mixing.

Abstract: A method is provided for controlling a power converter (220) to provide a uniform dimming range to a solid state lighting load (240) independent of a type of dimmer. The method includes detecting maximum and minimum phase angles of a dimmer (204) connected to the power converter (220) during operation of the solid state lighting load (240), and dynamically adjusting an output power of the power converter based on the detected maximum and minimum phase angles of the dimmer. The adjusted output power of the power converter adjusts a high end level of light output by the solid state lighting load at the maximum phase angle to match a predetermined high end value and adjusts a low end level of light output by the solid state lighting load at the minimum phase angle to match a predetermined low end value.

Abstract: A device for detecting a dimmer phase angle set by operation of a dimmer for a solid state lighting load includes a processor having a digital input, a first diode connected between the digital input and a voltage source and a second diode connected between the digital input and ground. The device further includes a first capacitor connected between the digital input and a detection node, a second capacitor connected between the detection node and ground, and a resistance connected between the detection node and a rectified voltage node, which receives a rectified voltage from the dimmer. The processor is configured to sample digital pulses at the digital input based on the rectified voltage and to identify the dimmer phase angle based on lengths of the sampled digital pulses.

Abstract: Disclosed are devices and related methods for optimally extending the range of light output of solid-state light sources, particularly at minimum light levels, through a power converter that includes a phase detector, a processing unit and a switch. The phase detector is configured to receive a voltage signal and to detect rising edges of waveforms of the voltage signal. The processing unit is configured to initiate a predetermined shutdown period in response to each detected rising edge. The switch is configured to provide a control signal that deactivates the power converter during the shutdown period, preventing the power converter from providing power to the solid state light unit during the shutdown period.

Abstract: Lighting apparatus and methods employing LED light sources are described. The LED light sources are integrated with other components in the form of a luminaire or other general purpose lighting structure. Some of the lighting structures are formed as Parabolic Aluminum Reflector (PAR) luminaires, allowing them to be inserted into conventional sockets. The lighting structures display beneficial operating characteristics, such as efficient operation, high thermal dissipation, high output, and good color mixing.