Circuitry for supplying electrical power to loads

• US 8,283,904 B2
• Filed: 09/13/2007
• Issued: 10/09/2012
• Est. Priority Date: 09/13/2006
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Myers, Peter Jay
• Primary Examiner(s): Laxton, Gary L
• Application Number:
  US11/854,744
• Publication Number:
  US 20080088248A1
• Time in Patent Office: 1,853 Days
• Field of Search: 323/225, 323/267, 323/268, 323/271, 363/21.12
• US Class Current: 323/267
• 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

the inductive element of the boost converter coupled to the input voltage, the flyback converter comprising;

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

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

a sub-circuit connected in series with the second diode, the sub-circuit comprising a first capacitive element and the second string of light emitting elements in parallel; and

a second capacitive element connected in series with the second diode and the sub-circuit.

2. The power supply of claim 1, wherein the boost converter further comprises:

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

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

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 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 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 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, a third sub-circuit and a third capacitor, the second diode and the third sub-circuit arranged in series,

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

the third capacitor electrically connected between a cathode end of the third sub-circuit and the secondary winding of the first transformer.

8. The circuit of claim 7, wherein the second sub-circuit is electrically connected to a cathode end of the first diode.

9. The circuit of claim 7, wherein the third sub-circuit is electrically connected to a cathode end of the second diode.

10. The circuit of claim 7, wherein the first switch is a MOSFET.

11. The circuit of claim 10, wherein the MOSFET is configured to control the level of current flowing through at least a first string of light emitting elements.

12. The circuit of claim 7, wherein voltage applied to the first load is based on a duty cycle of the first switch.

13. The circuit of claim 7, wherein at least one of the first load and the second load comprises at least a first solid state light emitting element.

14. The circuit of claim 13, wherein the first solid state light emitting element is an LED.

15. The circuit of claim 7, wherein a first voltage supplied to the first load differs from a second voltage supplied to the second load.

16. The circuit of claim 15, 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.

17. 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 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 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, a third sub-circuit and a third diode, the second diode and the third sub-circuit arranged in series,

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

the third diode electrically connected between a first node and a second node, the first node between a first end of the secondary winding of the first transformer and the anode end of the second diode, the second node between the cathode end of the third sub-circuit and a second end of the secondary winding of the first transformer.

18. The circuit of claim 17, wherein the 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.

19. 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 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 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 arranged in series,

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

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 arc 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.