Encapsulated electronic power converter with embedded AC components

• US 7,259,971 B1
• Filed: 11/20/2003
• Issued: 08/21/2007
• Est. Priority Date: 08/04/2003
• Status: Active Grant

• Current Assignee: Z-Axis Incorporated (Microsoft Corporation)
• Original Assignee: Z-Axis Incorporated (Microsoft Corporation)
• Inventors: Allen, Michael W., Kolbet, Robert J.
• Primary Examiner(s): Patel; Rajnikant B.
• Application Number:
  US10/717,887
• Time in Patent Office: 1,370 Days
• Field of Search: 363/21.12, 363/95, 363/97, 363/41, 363/74, 363/20, 363/131, 363/89, 363/57, 363/53, 363/45, 363/49, 363/21.13, 363/147, 439/502, 439/501, 361/799, 361/704, 361708-715, 174/16.3, 174/52.4
• US Class Current: 361/816
• CPC Class Codes: H01R 13/6675 with built-in power supply
• CPC Class Codes: H02M 3/28 using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
• CPC Class Codes: H02M 7/003 Constructional details, e.g. physical layout, assembly, wiring or busbar connections
• CPC Class Codes: Y10S 439/939 with grounding to metal mounting panel

Abstract

A self-contained and encapsulated AC to Voltage supplying module containing a complete set of AC circuitry components therein and directly connecting the components to the AC voltage source, an inrush protection circuit, a DC-DC converter and power control circuits which enable the encapsulation of AC and DC components within a module being directly mountable and DC electrically connected to a printed circuit board assembly.

Claims

1. An electronic power converter for supplying direct current power output from alternating current power input, comprising:

an encapsulated portion including at least high-voltage electronic circuitry where components of the at least high-voltage electronic circuitry are coated with an encapsulating high-dielectric material that is substantially free of voids therein to prevent breakdown; and

an integrated connector for receiving a detachable alternating current line cord, the alternating current line cord having at least two wires therein;

wherein said power converter is mountable as a component on a printed circuit board to supply direct current power to the printed circuit board.

2. The power converter of claim 1, further comprising an inrush current limiting circuit, said inrush current limiting circuit, including:

a. a bridge rectifier with a direct current return path;

b. a MOSFET switch connected to the direct current return path of the bridge rectifier;

c. a capacitor which is charged via a current limited source;

d. a voltage level detection circuit to maintain the MOSFET switch in an off state until a line voltage reaches a near zero threshold;

e. a resistive charging path to turn the MOSFET switch to an on state once the line voltage reaches the near zero threshold; and

f. a resistive connection to a housekeeping supply of the power converter which maintains the MOSFET switch in the on state.

3. The power converter of claim 1, further comprising:

a secondary side, isolated low voltage ON/OFF function, said function being implemented by circuitry including a transformer coupled peak detector to power a light emitter of an opto-coupler which has a photo-detector, the photo-detector being connected to the switching controller in a manner adequate to disable the power supply output in response to the signal received by the photo-detector, said emitter is also connected to a user accessible ON/OFF pin.

4. The power converter of claim 1, further comprising a low voltage sense function consisting of a peak detector connected to the power supply transformer for sensing a primary rectified voltage in a secondary low voltage manner;

and

a pin, accessible to the user, providing a signal representing the low voltage sense function.

5. The power converter of claim 4, further comprising:

a comparison circuit, connected to the peak detector, for comparing the peak detected voltage to a known reference voltage and producing a signal indicating a range within which the primary rectified voltage falls.

6. The power converter of claim 1, further comprising:

a secondary side, isolated low voltage ON/OFF function; and

a low voltage sense function, said functions being implemented by circuitry including a peak detector for sensing the instantaneous primary rectified voltage connected to a linear regulator/voltage limiting circuit, said linear regulator/voltage limiting circuit being further connected to a light emitter of an opto-coupler, said opto-coupler being further connected to an error amplifier and an ON/OFF pin in such a manner as to provide an isolated secondary low voltage indication of the primary line voltage and to allow the user to turn the device off.

7. An electronic encapsulated power converter, comprising:

a case;

circuitry for supplying direct current power output from alternating current power input;

an encapsulating material coating the circuitry, the encapsulating material having a high dielectric constant and thermal conductivity;

an integrated, 3-pin connector for receiving a detachable alternating current line cord, said connector accessible through said case; and

threaded mounts extending from said case, wherein the threaded mounts are earth grounded and allow the converter to be rigidly mounted as a component to a circuit board to supply power thereto.

8. An encapsulated alternating current to direct current power converter having an inrush current limiting circuit, said inrush current limiting circuit, including:

a. a bridge rectifier with a direct current return path;

b. a MOSFET switch connected to the direct current return path of the bridge rectifier;

c. a capacitor which is charged via a current limited source;

d. a voltage level detection circuit to maintain the MOSFET switch in an off state until a line voltage reaches a near zero threshold;

e. a resistive charging path to turn the MOSFET switch to an on state once the line voltage reaches the near zero threshold; and

f. a resistive connection to a housekeeping supply of the power converter which maintains the MOSFET switch in the on state;

wherein said current limiting circuit is encapsulated with the power converter.

9. The power converter of claim 8, further comprising:

a secondary side, isolated low voltage ON/OFF function, said function being implemented by circuitry including a transformer coupled peak detector to power a light emitter of an opto-coupler which has a photo-detector, the photo-detector being connected to the primary controller in a manner adequate to disable the power supply output in response to the signal received by the photo-detector, said emitter is also connected to a user accessible ON/OFF pin.

10. The power converter of claim 8, further comprising a low voltage sense function consisting of a peak detector connected to the power supply transformer for sensing a primary rectified voltage in a secondary low voltage manner;

and

a pin, accessible to the user, for providing a signal representing the low voltage sense function.

11. The power converter of claim 10, further comprising:

a comparison circuit, connected to the peak detector, for comparing the peak detected voltage to a known reference voltage and producing a signal indicating a range within which the primary rectified voltage falls.

12. The power converter of claim 8, further comprising

a secondary side, isolated low voltage ON/OFF function;

and

a low voltage sense function, said functions being implemented by circuitry including a peak detector for sensing the instantaneous primary rectified voltage connected to a linear regulator/voltage limiting circuit, said linear regulator/voltage limiting circuit being further connected to a light emitter of an opto-coupler, said opto-coupler being further connected to an error amplifier and an ON/OFF pin in such a manner as to provide an isolated secondary low voltage indication of the primary line voltage and to allow the user to turn the device off.

13. The power converter of claim 10, wherein the low voltage sense function is implemented by circuitry including:

a. a comparison circuit which compares an instantaneous primary voltage to a known reference voltage;

b. a peak detector, electrically connected to said comparison circuit, for sensing the instantaneous primary voltage and providing a signal indicating the instantaneous primary voltage to the comparison circuit; and

c. an independent pin, connected to the comparison circuit to provide an output signal when the instantaneous primary voltage is determined to be below the reference voltage.

14. An electronic device, comprising;

at least one circuit board located within the device;

a cover enclosing the electronic device; and

an electronic power converter including fully encapsulated electronic circuitry, the circuitry coated with an encapsulating material, the encapsulating material having thermal conductivity and a high dielectric constant; and

an integrated connector, accessed through an aperture in said cover, for receiving a detachable alternating current line cord, the alternating current line cord having at least two wires therein, wherein said power converter is mounted as a component on said circuit board to supply power to said circuit board.

15. The electronic device of claim 14, wherein said integrated connector of the power converter provides connection to an alternating current utility line source that is independent of the circuit board to which the power converter is attached.

16. The electronic device of claim 14, further comprising an inrush current limiting circuit, said inrush current limiting circuit, including:

a. a bridge rectifier with a direct current return path;

b. a MOSFET switch connected to the direct current return path of the bridge rectifier;

c. a capacitor which is charged via a current limited source;

d. a voltage level detection circuit to maintain the MOSFET switch in an off state until a line voltage reaches a near zero threshold;

e. a resistive charging path to turn the MOSFET switch to an on state once the line voltage reaches the near zero threshold; and

f. a resistive connection to a housekeeping supply of the power converter which maintains the MOSFET switch in the on state.

17. The electronic device of claim 16, further comprising:

a secondary side, isolated low voltage ON/OFF function, said function being implemented by circuitry including a transformer coupled peak detector to power a light emitter of an opto-coupler which has a photo-detector, the photo-detector being connected to the primary controller in a manner adequate to disable the power supply output in response to the signal received by the photo-detector, said emitter is connected to a user accessible ON/OFF pin.

18. The electronic device of claim 16, further comprising a low voltage sense function consisting of a peak detector connected to the power supply transformer for sensing a primary rectified voltage and providing a representative signal to a pin that is accessible to the user.

19. The electronic device of claim 18, further comprising:

a comparison circuit, connected to the peak detector, for comparing the peak detected voltage to a known reference voltage and producing a signal indicating a range within which the primary rectified voltage falls.

20. The electronic device of claim 16, further comprising:

a secondary side, isolated low voltage ON/OFF function; and

a low voltage sense function, said functions being implemented by circuitry including a peak detector for sensing the instantaneous primary rectified voltage connected to a linear regulator/voltage limiting circuit, said linear regulator/voltage limiting circuit being further connected to a light emitter of an opto-coupler, said opto-coupler being further connected to an error amplifier and an ON/OFF pin in such a manner as to provide an isolated secondary low voltage indication of the primary line voltage and to allow the user to turn the device off.