POWER SUPPLY UNIT FOR USE WITH AN AIRCRAFT ELECTRICAL SYSTEM

• US 20080238191A1
• Filed: 03/21/2008
• Published: 10/02/2008
• Est. Priority Date: 03/26/2007
• Status: Active Grant

• Current Assignee: Champion Aerospace, LLC (Transdigm Group Incorporated)
• Original Assignee: Champion Aerospace, LLC (Transdigm Group Incorporated)
• Inventors: Lockmiller, Robert A., Davis, Scott A., Berllner, James R., Cottingham, John D.
• Granted Patent: US 7,750,496 B2
• Time in Patent Office: Days
• US Class Current: 307/9.1
• CPC Class Codes: H02J 2310/44 for aircrafts
• CPC Class Codes: H02J 9/06 with automatic change-over , e.g. UPS systems

Abstract

A power supply unit that provides uninterrupted power to an aircraft power bus during switchovers of the aircraft bus from one power source to another. The power supply unit includes circuitry to distinguish between loss of bus power due to switchovers between power sources and loss of bus power due to shutdown of the aircraft. The power supply unit includes a low voltage lockout circuit to interrupt the supply of power when the aircraft bus voltage falls below a minimum value.

Claims

1. A power supply unit for use with an aircraft power bus, comprising:

a connection circuit being electrically coupled to the aircraft power bus and providing the power supply unit with both charge and discharge paths; and

an energy storage circuit being electrically coupled to the connection circuit, wherein during charging periods the energy storage circuit receives charge from the aircraft power bus through the charge path, and during discharging periods the energy storage circuit provides charge to the aircraft power bus through the discharge path.

2. The power supply unit of claim 1, further comprising a comparator circuit that is electrically coupled to the energy storage circuit and determines if there is adequate voltage on the aircraft power bus.

3. The power supply unit of claim 1, further comprising a pulse circuit that is electrically coupled to the energy storage circuit and reduces the amount of power used by the power supply unit during operation.

4. The power supply unit of claim 1, further comprising a time delay circuit that is electrically coupled to the comparator circuit and distinguishes when a loss of power on the aircraft power bus is due to a temporary disruption and when it is due to a desired shut down.

5. The power supply unit of claim 1, further comprising a low voltage lockout circuit that is electrically coupled to the connection circuit and detects when the voltage on the aircraft power bus falls below a predetermined threshold.

6. The power supply unit of claim 5, wherein the low voltage lockout circuit also acts as a short circuit fault detection.

7. A power supply unit for use with an aircraft power bus, comprising:

a connection circuit having positive and negative input terminals for connecting to two corresponding terminals of an aircraft power bus; and

an energy storage circuit electrically connected to said connection circuit;

wherein said connection circuit provides separate charging and discharging paths between said input terminals and said energy storage circuit, and wherein said connection circuit includes an impedance in said charging path and a switch in said discharge path; and

wherein said power supply unit controls operation of said switch based on voltage differences between two nodes located at opposite ends of said impedance.

8. The power supply unit of claim 7, wherein the connection circuit includes at least one diode in each of the paths.

9. The power supply unit of claim 7, wherein the switch is normally maintained in an on state such that power from the energy storage circuit can be instantaneously supplied to the aircraft power bus during switchovers of bus power from different aircraft power sources.

10. The power supply unit of claim 7, wherein said energy storage circuit comprises a plurality of energy storage devices and a second impedance defining a path in parallel with said energy storage devices.

11. The power supply unit of claim 10, wherein said energy storage devices comprise capacitors.

12. The power supply unit of claim 10, further comprising a pulse circuit in series with said second impedance to switch said impedance in and out of circuit at a selected duty cycle.

13. The power supply unit of claim 7, further comprising a comparator circuit and a timer delay circuit that controls operation of said switch, said comparator circuit being electrically connected to the nodes and having an input electrically connected to an input of the timer delay circuit, and wherein said comparator circuit and said timer delay circuit together operate to turn off said switch if the aircraft power bus has lost power for more than a selected amount of time.

14. The power supply unit of claim 7, further comprising a low voltage lockout circuit that is electrically coupled to the connection circuit and detects when the voltage on the aircraft power bus falls below a predetermined threshold.

15. The power supply unit of claim 7, wherein said switch comprises a transistor.

16. The power supply unit of claim 7, wherein said input terminals are the only electrical connections on said power supply unit.