Thermal management system

• US 8,503,494 B2
• Filed: 04/05/2011
• Issued: 08/06/2013
• Est. Priority Date: 04/05/2011
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Yee, Dawson
• Primary Examiner(s): NGUYEN, DUNG T
• Application Number:
  US13/080,549
• Publication Number:
  US 20120257646A1
• Time in Patent Office: 854 Days
• Field of Search: 372 34- 36
• US Class Current: 372/36
• CPC Class Codes: G05D 23/192 using a modification of the thermal impedance between a source and the load

Abstract

Various embodiments are disclosed for a thermal management system and related method for selectively thermally isolating and thermally connecting a target component. One embodiment of a system includes a first component having a first surface proximate to a target component, and an electromagnet between the first surface and the target component. A second component is spaced apart from the first component to form a gap that serves as a thermal boundary between the first component and the second component. A carrier fluid disposed within the gap includes multiple thermally conductive, ferrous particles. The carrier fluid is configured to align at least a portion of the thermally conductive, ferrous particles when the electromagnet generates a magnetic field that attracts the particles, and to displace at least a portion of the particles when the electromagnet generates a magnetic field that repels the particles.

Claims

1. A thermal management system for selectively thermally isolating and thermally connecting a target component, comprising:

a first component having a first surface proximate to the target component;

a first electromagnet between the first surface and the target component;

a second component spaced apart from the first component;

a gap serving as a thermal boundary between the first component and the second component;

a carrier fluid disposed within the gap and including multiple thermally conductive, ferrous particles, the carrier fluid being configured to align at least a portion of the thermally conductive, ferrous particles across a central region of the gap when the first electromagnet generates a magnetic field that attracts the particles, and to displace at least a portion of the particles from the central region of the gap when the first electromagnet generates a magnetic field that repels the particles, the carrier fluid and the first electromagnet operating to selectively thermally connect and thermally isolate the target component.

2. The system of claim 1, further including a magnet proximate to the second component.

3. The system of claim 2, wherein the magnet proximate to the second component is a permanent magnet.

4. The system of claim 2, wherein the magnet proximate to the second component is a second electromagnet.

5. The system of claim 4, further including:

a power supply configured to supply power to the first electromagnet and the second electromagnet; and

a controller operably connected to the power supply and configured to selectively control the first electromagnet and the second electromagnet to either attract at least a portion of the thermally conductive, ferrous particles and align the particles across the central region of the gap, or to repel at least a portion of the thermally conductive, ferrous particles and displace the particles from the central region of the gap.

6. The system of claim 5, further comprising instructions executed by the controller to selectively control the power supply to energize the first electromagnet to generate a magnetic field that either aligns the thermally conductive, ferrous particles across the central region of the gap, or displaces the thermally conductive, ferrous particles from the central region of the gap.

7. The system of claim 1, further including a heat sink proximate to the second component.

8. The system of claim 1, wherein the first component and the second component are ring-shaped.

9. The system of claim 1, wherein the first component and the second component are comprised of a non-ferrous material, and further comprising a spacer between the first component and the second component, the spacer having a first thermal conductivity that is lower than a second thermal conductivity of the first component and the second component.

10. The system of claim 9, wherein the spacer comprises an elastomeric O-ring.

11. The system of claim 1, wherein the target component is a laser diode in a depth camera used in a gaming system.

12. A method for selectively thermally isolating and thermally connecting a target component that generates heat, comprising:

controlling a first electromagnet to attract thermally conductive, ferrous particles within a carrier fluid and align at least a portion of the particles across a central region of a gap between the target component and a heat sink that is spaced apart across the gap from the target component to enhance heat transfer from the target component to the heat sink, and

controlling the first electromagnet to repel the thermally conductive, ferrous particles and displace at least a portion of the particles from the central region of the gap between the target component and the heat sink to inhibit heat transfer from the target component to the heat sink.

13. The method of claim 12, further comprising the steps of:

sensing an actual temperature of the target component;

comparing the actual temperature of the target component to a first threshold temperature; and

if the actual temperature is above the first threshold temperature, controlling the first electromagnet to attract at least a portion of the thermally conductive, ferrous particles and enhance heat transfer from the target component to the heat sink.

14. The method of claim 13, further comprising the steps of:

comparing the actual temperature of the target component to a second threshold temperature; and

if the actual temperature is below the second threshold temperature, controlling the first electromagnet to repel at least a portion of the thermally conductive, ferrous particles and inhibit heat transfer from the target component to the heat sink.

15. The method of claim 12, wherein a permanent magnet is proximate to the heat sink.

16. The method of claim 15, wherein:

controlling a first electromagnet to attract thermally conductive, ferrous particles further comprises controlling the first electromagnet in combination with the permanent magnet to attract the thermally conductive, ferrous particles within the carrier fluid and align at least a portion of the particles across the central region of the gap between the target component and the heat sink that is spaced apart across the gap from the target component to enhance heat transfer from the target component to the heat sink, and

controlling a first electromagnet to repel the thermally conductive, ferrous particles further comprises controlling the first electromagnet in combination with the permanent magnet to repel the thermally conductive, ferrous particles and displace at least a portion of the particles from the central region of the gap between the target component and the heat sink to inhibit heat transfer from the target component to the heat sink.

17. The method of claim 13, wherein a second electromagnet is proximate to the heat sink.

18. The method of claim 17, further comprising the step of, if the actual temperature is above the first threshold temperature, controlling the first electromagnet and the second electromagnet to attract at least a portion of the thermally conductive, ferrous particles and enhance heat transfer from the target component to the heat sink.

19. The method of claim 18, further comprising the steps of:

if the actual temperature is below a second threshold temperature, controlling the first electromagnet and the second electromagnet to repel at least a portion of the thermally conductive, ferrous particles and inhibit heat transfer from the target component and the first component to the second component.

20. A thermal management system for selectively thermally isolating and thermally connecting a laser diode in a depth camera to a heat sink, comprising:

a first thermally conductive component having a first surface proximate to the laser diode;

a first electromagnet between the first surface and the laser diode;

a second thermally conductive component spaced apart from the first component, the second component proximate to the heat sink;

a second electromagnet proximate to the second component;

a gap serving as a thermal boundary between the first component and the second component;

a carrier fluid disposed within the gap and including multiple thermally conductive, ferrous particles, the carrier fluid being configured to align at least a portion of the thermally conductive, ferrous particles across a central region of the gap when the first electromagnet and the second electromagnet generate a magnetic field that attracts the particles, and to displace at least a portion of the particles from the central region of the gap when the first electromagnet and the second electromagnet generate a magnetic field that repels the particles;

a power supply configured to supply power to the first electromagnet and the second electromagnet; and

a controller operably connected to the power supply and configured to selectively control the first electromagnet and the second electromagnet to either attract at least a portion of the thermally conductive, ferrous particles and enhance heat transfer from the laser diode to the heat sink, or to repel at least a portion of the thermally conductive, ferrous particles and inhibit heat transfer from the laser diode to the heat sink.