Dongsheng Zhou

Bio: Dongsheng Zhou is an academic researcher. The author has contributed to research in topics: Solid-state lighting & Dimmer. The author has an hindex of 9, co-authored 11 publications receiving 1680 citations.

Apparatus, Method and System for Providing AC Line Power to Lighting Devices

Abstract: An apparatus, method and system are disclosed for providing AC line power to lighting devices such as light emitting diodes (“LEDs”). A representative apparatus comprises: a plurality of LEDs coupled in series to form a plurality of segments of LEDs; first and second current regulators; a current sensor; and a controller to monitor a current level through a series LED current path, and to provide for first or second segments of LEDs to be in or out of the series LED current path at different current levels. A voltage regulator is also utilized to provide a voltage during a zero-crossing interval of the AC voltage. In a representative embodiment, first and second segments of LEDs are both in the series LED current path regulated at a lower current level compared to when only the first segment of LEDs is in the series LED current path.

Adaptive Current Regulation for Solid State Lighting

Abstract: Exemplary embodiments provide an apparatus, system and method for power conversion to provide power to solid state lighting, and which may be coupled to a first switch, such as a dimmer switch. An exemplary system comprises: a switching power supply; solid state lighting; a first adaptive interface circuit to provide a resistive impedance to the first switch and conduct current from the first switch in a default mode; and a second adaptive interface circuit to create a resonant process. An exemplary apparatus comprises: a switching power supply; and an adaptive interface circuit comprising a resistive impedance coupled in series to a reactive impedance to conduct current from the first switch in a first current path in a default mode, and further comprising a second switch coupled to the reactive impedance to conduct current from the first switch in a second current path, with the adaptive interface circuit further damping oscillation when the first switch turns on.

Impedance matching circuit for current regulation of solid state lighting

Abstract: Exemplary embodiments provide an impedance matching circuit for providing variable power from a dimmer switch having a triac to a switching power supply couplable to solid-state lighting. An exemplary impedance matching circuit includes a first resistor coupled to receive a first current from the switching power supply; a second resistor; and a transistor coupled in series to the second resistor, with the transistor responsive to a gate voltage to modulate a second current through the second resistor in response to a detected level of the first current through the first resistor.

Digital Driver Apparatus, Method and System for Solid State Lighting

Abstract: An apparatus, method and system are provided for controlling the solid state lighting, such as LEDs. An exemplary apparatus comprises: a switch for switching electrical current through the LEDs, a current sensor; a first comparator adapted to determine when a switch electrical current has reached a first predetermined threshold; a second comparator adapted to determine when the switch electrical current has reached a predetermined average current level; and a controller. The controller is adapted to turn the switch into an on state and an off state, to determine a first on time period as a duration between either a detection of a second predetermined current threshold or the turning the switch into the on state, and the detection of the predetermined average current level; to determine a second on time period as a duration between the detection of the predetermined average current level and the detection of the first predetermined current threshold; and to determine an on time period of the switch as substantially proportional to a sum of the first on time period and the second on time period. Additional exemplary embodiments utilize a difference between the first and second on time periods to generate an error signal to adjust the on time period of the switch.

System and Method for Regulation of Solid State Lighting

Abstract: Exemplary embodiments of the invention provide a system, apparatus, and method of controlling an intensity and spectrum of light emitted from a solid state lighting system. The solid state lighting has a first emitted spectrum at full intensity and at a selected temperature, with a first electrical biasing for the solid state lighting producing a first wavelength shift, and a second electrical biasing for the solid state lighting producing a second, opposing wavelength shift. Exemplary embodiments provide for receiving information designating a selected intensity level or a selected temperature; and providing a combined first electrical biasing and second electrical biasing to the solid state lighting to generate emitted light having the selected intensity level and having a second emitted spectrum within a predetermined variance of the first emitted spectrum over a predetermined range of temperatures.

Apparatus, Method and System for Providing AC Line Power to Lighting Devices

Abstract: An apparatus, method and system are disclosed for providing AC line power to lighting devices such as light emitting diodes (“LEDs”). A representative apparatus comprises: a plurality of LEDs coupled in series to form a plurality of segments of LEDs; first and second current regulators; a current sensor; and a controller to monitor a current level through a series LED current path, and to provide for first or second segments of LEDs to be in or out of the series LED current path at different current levels. A voltage regulator is also utilized to provide a voltage during a zero-crossing interval of the AC voltage. In a representative embodiment, first and second segments of LEDs are both in the series LED current path regulated at a lower current level compared to when only the first segment of LEDs is in the series LED current path.

Circuits and methods for driving light sources

Abstract: A driving circuit includes a first inductor coupled in series with a light source for providing power to the light source. A controller coupled to the first inductor can control a switch coupled to the first inductor, thereby controlling a current flowing through the first inductor. A current sensor coupled to the first inductor can provide a first signal indicative of the current flowing through the first inductor, regardless of whether the switch is on or off. The switch is controlled according to the first signal. A second inductor magnetically coupled to the first inductor is also electrically coupled to the first inductor via a common node between the switch and the first inductor for providing a reference ground for the controller. The reference ground is different from the ground of the driving circuit.

Power control system for current regulated light sources

Abstract: A light emitting diode (LED) lighting system includes a PFC and output voltage controller and a LED lighting power system. The controller advantageously operates from an auxiliary voltage less than a link voltage generated by the LED lighting power system. The common reference voltage allows all the components of lighting system to work together. A power factor correction switch and an LED drive current switch are coupled to the common reference node and have control node-to-common node, absolute voltage that allows the controller to control the conductivity of the switches. The LED lighting system can utilize feed forward control to concurrently modify power demand by the LED lighting power system and power demand of one or more LEDs. The LED lighting system can utilize a common current sense device to provide a common feedback signal to the controller representing current in at least two of the LEDs.

Adaptive Current Regulation for Solid State Lighting

Abstract: Exemplary embodiments provide an apparatus, system and method for power conversion to provide power to solid state lighting, and which may be coupled to a first switch, such as a dimmer switch. An exemplary system comprises: a switching power supply; solid state lighting; a first adaptive interface circuit to provide a resistive impedance to the first switch and conduct current from the first switch in a default mode; and a second adaptive interface circuit to create a resonant process. An exemplary apparatus comprises: a switching power supply; and an adaptive interface circuit comprising a resistive impedance coupled in series to a reactive impedance to conduct current from the first switch in a first current path in a default mode, and further comprising a second switch coupled to the reactive impedance to conduct current from the first switch in a second current path, with the adaptive interface circuit further damping oscillation when the first switch turns on.

Wireless lighting control system

Abstract: A lighting device includes a DC/DC power converter, a controller/processor electrically connected to the DC/DC power converter, a light emitting diode (LED) current control circuit communicably coupled to the controller/processor and electrically connected to the DC/DC power converter, and two or more LEDs comprising at least a first color LED and a second color LED electrically connected to the LED current control circuit. The LED current control circuit provides an on/off signal having a cycle time to each LED in response to one or more control signals received from the controller/processor such that the two or more LEDs produce a blended light having a specified color based on how long each LED is turned ON and/or OFF during the cycle time.