Single inductor control of multi-color LED systems
AssigneeSwitch Bulb Company, Inc.
InventorRonald J. Lenk
Life of this patent
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Abstract
A circuit for driving multiple light emitting diodes (LEDs) includes at least two sets of LEDs, each set comprised of one or more LEDs in series. The circuit further includes a single inductor connected in series with the two sets of LEDs. At least one set of LEDs is connected to a shunting transistor connected in parallel with the set of LEDs. The duty cycle of the shunting transistor is controlled by a single controller connected to the shunting transistor and the inductor.
Claims24
A circuit for driving multiple sets of light emitting diodes (LEDs), the circuit comprising:
- a first set of LEDs comprised of one or more LEDs in series;
- a second set of LEDs comprised of one or more LEDs in series, wherein the first set of LEDs is configured to produce different color or color spectrum than the second set of LEDs;
- a single inductor connected in series with the first and second sets of LEDs;
- a first shunting transistor connected in parallel with the second set of LEDs;
- and
- a single controller connected to the single inductor and the first shunting transistor, wherein the controller is configured to set a first duty cycle of the first shunting transistor, and wherein the first set of LEDs is not connected in parallel with a shunting transistor.
A circuit for driving multiple sets of light emitting diodes (LEDs), the circuit comprising:
- a first set of LEDs comprised of one or more LEDs in series;
- a second set of LEDs comprised of one or more LEDs in series;
- a third set of LEDs comprised of one or more LEDs in series, wherein the first set of LEDs is configured to produce different color or color spectrum than the second and third sets of LEDs, wherein the second set of LEDs is configured to produce different color or color spectrum than the first and third sets of LEDs;
- a single inductor connected in series with the first, second, and third sets of LEDs;
- a first shunting transistor connected in parallel with the second set of LEDs;
- a second shunting transistor connected in parallel with the third set of LEDs;
- and
- a single controller connected to the first shunting transistor and the second shunting transistor, wherein the controller is configured to control a first duty cycle of the first shunting transistor and a second duty cycle of the second shunting transistor;
- and wherein the first set of LEDs is not connected in parallel with a shunting transistor.
A method of building a circuit for driving multiple sets of LEDs, the method comprising:
- connecting a single inductor in series to a first set of LEDs comprised of one or more LEDs in series;
- connecting the first set of LEDs in series to a second set of LEDs comprised of one or more LEDs in series, wherein the first set of LEDs is configured to produce different color or color spectrum than the second set of LEDs;
- connecting a first shunting transistor in parallel with the second set of LEDs, wherein the first set of LEDs is not connected in parallel with a shunting transistor;
- and
- connecting a single controller to the first shunting transistor, wherein the controller is configured to control a first duty cycle of the first shunting transistor.
Dependencies are inferred from the claim text.