Back to results
US 10,834,792 B2Granted
AC-driven light-emitting diode systems
AssigneeIntelesol, LLC
InventorsMark D. Telefus, Stephen C. Gerber
Life of this patent
Estimating the term…
Abstract
AC-driven light-emitting diode systems and methods are provided for driving LED devices (e.g., LED lighting) using AC power. For example, an integrated circuit includes a first power line and a second power line configured for connection to AC power, and a plurality of LED stages, wherein each LED stage comprises multiple serially-connected LED devices, switches connected to inputs and outputs of the LED stages. The integrated circuit further includes switch control circuitry configured to control the switches to selectively connect one or more of the LED stages to the first and second power lines to empower the LED stages with the AC power.
Claims20
An integrated circuit comprising:
- a first power line and a second power line configured for connection to alternating-current (AC) power;
- a plurality of light-emitting diode (LED) stages, wherein each LED stage comprises a plurality of LED devices that are serially-connected between an input node and an output node of the LED stage;
- a plurality of switches connected to the input and output nodes of the LED stages and to the first and second power lines, wherein for each LED stage of the plurality of LED stages (i) the input node of the LED stage is coupled to the first power line through a respective first switch of the plurality of switches, (ii) the input node of the LED stage is coupled to the second power line through a respective second switch of the plurality of switches, (iii) the output node of the LED stage is coupled to the first power line through a respective third switch of the plurality of switches, and (iv) the output node of the LED stage is coupled to the second power line through a respective fourth switch of the plurality of switches;
- and
- switch control circuitry configured to control the plurality of switches to selectively connect one or more of the LED stages to the first and second power lines to selectively empower the one or more LED stages with the AC power;
- wherein in controlling the plurality of switches, the switch control circuitry is configured to:
- (i) during a first half-cycle of AC power applied to the first and second power lines, selectively connect the input node of a given LED stage of the plurality of LED stages to the first power line through activation of the respective first switch, and selectively connect the output node of the given LED stage to the second power line through activation of the respective fourth switch;
- and
- (ii) during a second half-cycle of the applied AC power, selectively connect the input node of the given LED stage to the second power line through activation of the respective second switch, and selectively connect the output node of the given LED stage to the first power line through activation of the respective third switch.
6 more elements
A method comprising:
- applying alternating-current (AC) power to first and second power lines of a light generating device comprising a plurality of light-emitting diode (LED) stages and a plurality of switches, wherein each LED stage comprises a plurality of LED devices that are serially-connected between an input node and an output node of the LED stage, and wherein the plurality of switches are connected to the input and output nodes of the LED stages and to the first and second power lines, wherein for each LED stage of the plurality of LED stages (i) the input node of the LED stage is coupled to the first power line through a respective first switch of the plurality of switches, (ii) the input node of the LED stage is coupled to the second power line through a respective second switch of the plurality of switches, (iii) the output node of the LED stage is coupled to the first power line through a respective third switch of the plurality of switches, and (iv) the output node of the LED stage is coupled to the second power line through a respective fourth switch of the plurality of switches;
- and
- controlling the plurality of switches to selectively connect one or more LED stages of the plurality of LED stages to the first and second power lines to selectively empower the one or more LED stages with the AC power;
- wherein controlling the plurality of switches comprises:
- (i) during a first half-cycle of the applied AC power, selectively connecting the input node of a given LED stage of the plurality of LED stages to the first power line through activation of the respective first switch, and selectively connecting the output node of the given LED stage to the second power line through activation of the respective fourth switch;
- and
- (ii) during a second half-cycle of the applied AC power, selectively connecting the input node of the given LED stage to the second power line through activation of the respective second switch, and selectively connecting the output node of the given LED stage to the first power line through activation of the respective third switch.
4 more elements
A light generating device, comprising:
- a semiconductor wafer comprising a monolithic integrated circuit, wherein the monolithic integrated circuit comprises:
- alternating-current (AC) power input terminals configured for connection to an AC power source, and a first power line and a second power line coupled to respective ones of the AC power input terminals;
- a plurality of light-emitting diode (LED) stages, wherein each LED stage comprises a plurality of LED devices that are serially-connected between an input node and an output node of the LED stage;
- switching circuitry comprising a plurality of switches connected to the input and output nodes of the LED stages and to the first and second power lines, wherein for each LED stage of the plurality of LED stages (i) the input node of the LED stage is coupled to the first power line through a respective first switch of the plurality of switches, (ii) the input node of the LED stage is coupled to the second power line through a respective second switch of the plurality of switches, (iii) the output node of the LED stage is coupled to the first power line through a respective third switch of the plurality of switches, and (iv) the output node of the LED stage is coupled to the second power line through a respective fourth switch of the plurality of switches;
- and
- switch control circuitry configured to control the plurality of switches to selectively connect one or more of the LED stages to the first and second power lines to empower the one or more LED stages with AC power from the AC power source;
- wherein in controlling the plurality of switches, the switch control circuitry is configured to:
- (i) during a first half-cycle of AC power applied to the first and second power lines, selectively connect the input node of a given LED stage of the plurality of LED stages to the first power line through activation of the respective first switch, and selectively connect the output node of the given LED stage to the second power line through activation of the respective fourth switch;
- and
- (ii) during a second half-cycle of the applied AC power, selectively connect the input node of the given LED stage to the second power line through activation of the respective second switch, and selectively connect the output node of the given LED stage to the first power line through activation of the respective third switch.
7 more elements
Dependencies are inferred from the claim text.