CIRCUITRY FOR SUPPLYING ELECTRICAL POWER TO LOADS

• US 20080088248A1
• Filed: 09/13/2007
• Published: 04/17/2008
• Est. Priority Date: 09/13/2006
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: LED Lighting Fixtures, Inc. (Wolfspeed, Inc.)
• Inventors: MYERS, Peter
• Granted Patent: US 8,283,904 B2
• Time in Patent Office: Days
• US Class Current: 315/210
• CPC Class Codes: H02M 3/335 using semiconductor devices only

Abstract

A power supply, comprising a boost converter which provides voltage to a first load, and a flyback converter which provides voltage to a second load and which utilizes an inductive element of the boost converter as a primary winding of a transformer of the flyback converter. Also, a power supply comprising a MOSFET which is disposed between solid state elements and a second reference potential and which controls current flowing through the solid state elements. Also, a circuit comprising a transformer, a first circuit portion comprising the primary winding of the transformer and a second circuit portion comprising the secondary winding of the transformer. Also, a power supply comprising means for using a common transformer for providing a boost converter and a flyback converter. Also, a power supply comprising a transformer, means for providing a boost converter utilizing the transformer, and means for providing a flyback converter utilizing the transformer.

Claims

1. A power supply, comprising:

a boost converter configured to provide a voltage higher than an input voltage to a first load; and

a flyback converter configured to provide a voltage to a second load, the flyback converter utilizing an inductive element of the boost converter as a primary winding of a transformer of the flyback converter.

2. The power supply of claim 1, wherein the inductive element of the boost converter is coupled to the input voltage, the boost converter further comprising:

a diode coupled between the inductive element and the string of light emitting elements; and

a switching element coupled between the inductive element and a reference voltage; and

wherein the flyback converter comprises;

a secondary winding configured to be coupled to the primary winding;

a diode coupled between the secondary winding and a second string of light emitting elements; and

a capacitive element coupled to the diode and in parallel to the second string of light emitting elements.

3. The power supply of claim 2, further comprising a control circuit configured to control the switching element to provide a predefined frequency and duty cycle with which the switching element is opened and closed.

4. The power supply of claim 1, wherein at least one of said first load and said second load comprises a string of light emitting elements.

5. The power supply of claim 4, wherein at least one of said light emitting elements comprises a solid state light emitter.

6. The power supply of claim 1, wherein said first load and said second load each comprise a string of light emitting elements.

7. A power supply for driving solid state light emitting elements, the solid state elements being coupled between a first reference potential and a second reference potential, the power supply comprising:

a metal-oxide semiconductor field effect transistor (MOSFET) disposed between the solid state elements and the second reference potential, the MOSFET being configured to control the level of current flowing through the solid state elements.

8. A circuit for supplying power, comprising:

at least a first transformer, the first transformer comprising a primary winding and a secondary winding;

a first circuit portion; and

a second circuit portion,

the first circuit portion comprising the primary winding of the first transformer, at least a first switch and a first sub-circuit, the first switch and the first sub-circuit being arranged in parallel,

the first sub-circuit comprising at least a first diode and a second sub-circuit, the first diode and the second sub-circuit being arranged in series,

the second sub-circuit comprising at least a first capacitor and at least a first load arranged in parallel,

the second circuit portion comprising the secondary winding of the first transformer, at least a second diode and a third sub-circuit, the second diode and the third sub-circuit being arranged in series,

the third sub-circuit comprising at least a second capacitor and at least a second load arranged in parallel.

9. The circuit of claim 8, wherein the second sub-circuit is electrically connected to a cathode end of the first diode.

10. The circuit of claim 8, wherein the second capacitor is electrically connected to a cathode end of the third sub-circuit.

11. The circuit of claim 8, wherein the third sub-circuit is electrically connected to a cathode end of the second diode.

12. The circuit of claim 8, wherein the first switch is a MOSFET.

13. The circuit of claim 8, wherein voltage applied to the first load is based on a duty cycle of the first switch.

14. The circuit of claim 8, wherein the second circuit portion further comprises at least a third diode electrically connected between a first node and a second node, the first node being between a first end of the secondary winding of the first transformer and the anode end of the second diode, the second node being between the cathode end of the third sub-circuit and a second end of the secondary winding of the first transformer.

15. The circuit of claim 14, wherein the second circuit portion further comprises at least a third capacitor electrically connected between the second end of the secondary winding of the first transformer and a node which is electrically connected to a cathode end of the third sub-circuit and to a cathode end of the third diode.

16. The circuit of claim 8, wherein the second circuit portion further comprises at least a third capacitor electrically connected between a cathode end of the third sub-circuit and the second end of the secondary winding of the first transformer.

17. The circuit of claim 8, wherein at least one of the first load and the second load comprises at least a first solid state light emitting element.

18. The circuit of claim 17, wherein the first solid state light emitting element is an LED.

19. The circuit of claim 8, wherein:

at least one of the first load and the second load comprises at least a first solid state light emitting element, at least a first transistor, at least a first resistor and at least a first operational amplifier,

the first solid state light emitting element, the first transistor, and the first resistor are arranged in series,

a cathode end of the first solid state light emitting element is electrically connected to a source of the first transistor,

the first resistor is electrically connected to a collector of the first transistor, and

the operational amplifier drives a gate voltage of the first transistor, a reference voltage is provided as a first input to the operation amplifier and a voltage from a node between the collector of the first transistor and the first resistor is a second input to the operational amplifier.

20. The circuit of claim 8, wherein a first voltage supplied to the first load differs from a second voltage supplied to the second load.

21. The circuit of claim 20, wherein the first voltage is applied to the first load during at least a portion of a time that the second voltage is applied to the second load.

22. A power supply comprising:

means for using a common transformer for providing a boost converter and a flyback converter.

23. A power supply comprising:

a transformer;

means for providing a boost converter utilizing the transformer; and

means for providing a flyback converter utilizing the transformer.