Prior art

The following prior art references were cited against US patent 7939967. The analysis below identifies key aspects of each citation and their potential relevance under 35 U.S.C. § 102.

Most Relevant Prior Art for US7939967

1. US4860188A — Redundant power supply control

• Full Citation: US4860188A, "Redundant power supply control" by Nadd; Michael J. (Dallas, Tex.), assigned to Texas Instruments Incorporated.
• Publication/Filing Date: Filed May 2, 1988, published August 22, 1989.
• Brief Description: This patent describes a redundant power supply system where two or more power supplies are connected in parallel to a common load. A fault in one power supply is detected, and a control circuit ensures the remaining good power supply takes over the load without interruption. Specifically, it discusses detecting a fault in a primary regulator and using a control signal to activate a redundant regulator.
• Potential Anticipation (35 U.S.C. § 102): This patent appears highly relevant to claims 1, 9, and 14 of US7939967. It describes a system with multiple power supplies, a load, and independent sources (implicitly, as redundant supplies are often from independent or isolated sources). It explicitly teaches detecting a fault (anomalous condition) in one supply and switching to a redundant supply, which inherently involves one supply transitioning from a lesser/standby state to a greater/normal output state in response to an alert/fault signal. The concept of uninterrupted power during switchover is also central. The "Redundant power supply control" aspect directly aligns with the core invention of US7939967.

2. US5894413A — Redundant power supply switchover circuit

• Full Citation: US5894413A, "Redundant power supply switchover circuit" by Nakajima; Haruki (Tokyo, JP), assigned to Sony Corporation.
• Publication/Filing Date: Filed January 28, 1997, published April 13, 1999.
• Brief Description: This patent describes a power supply switchover circuit for switching between a first power supply and a redundant second power supply when the first power supply fails. It includes a monitoring circuit for detecting a drop in output voltage of the first power supply and generating a switching signal. A switching circuit then connects the load to the second power supply.
• Potential Anticipation (35 U.S.C. § 102): This reference is highly relevant to claims 1, 9, and 14 of US7939967 due to its focus on a redundant power supply system with switchover upon failure detection. The detection of a "drop in output voltage" is an "anomalous condition," and the generation of a "switching signal" acts as an "alert signal" or "activation signal." The second power supply taking over the load corresponds to transitioning from a standby/lesser output to a normal/greater output level.

3. US20090224603A1 — Energy conserving (stand-by mode) power saving design for battery chargers and power supplies

• Full Citation: US20090224603A1, "Energy conserving (stand-by mode) power saving design for battery chargers and power supplies" by Perper; Harry Leonard (Palm Beach Gardens, FL).
• Publication/Filing Date: Filed March 7, 2008, published September 10, 2009.
• Brief Description: This publication discloses a power supply configured for energy conservation by operating in a stand-by mode when not in use. While it focuses on energy saving rather than fault tolerance, it describes systems with power supplies having standby modes and transitioning out of them.
• Potential Anticipation (35 U.S.C. § 102): This reference is relevant to the "standby mode" and "transitioning from a lesser output level to a greater output level" aspects of claims 1, 6, 9, 10, and 14 of US7939967. While its primary motivation is energy saving rather than redundancy upon failure, it establishes the concept of a power supply operating in a standby (lesser output) mode and then activating to a normal (greater output) mode. The novelty of US7939967 might rest on the trigger for this transition (anomalous condition of a source) and the maintenance of power during the transition.

4. US7701089B2 — Power supply circuit

• Full Citation: US7701089B2, "Power supply circuit" by Shirasaka; Yoshiya (Sagamihara, JP), assigned to Ricoh Company, Ltd.
• Publication/Filing Date: Filed August 12, 2005, published April 20, 2010.
• Brief Description: This patent describes a power supply circuit with multiple power supply units and a control unit that selects one of the power supply units to output power based on an external control signal. It also details standby power supplies.
• Potential Anticipation (35 U.S.C. § 102): This patent, particularly the mention of "standby power supplies" and a "control unit that selects one of the power supply units to output power," is relevant to claims 1, 6, 9, 10, and 14 of US7939967. The "external control signal" could be considered an "activation signal" that causes a power supply to transition from a standby (lesser) to an active (greater) output level. Its relevance would depend on whether the control signal is triggered by an anomalous condition of another power source, which is a key distinguishing feature of US7939967.

5. US5200643A — Parallel electric power supplies with current sharing and redundancy

• Full Citation: US5200643A, "Parallel electric power supplies with current sharing and redundancy" by Williams; Charles E. (Plano, Tex.), assigned to Westinghouse Electric Corp.
• Publication/Filing Date: Filed February 21, 1989, published April 6, 1993.
• Brief Description: This patent describes multiple power supplies connected in parallel to a common load, with a current sharing circuit to ensure each supply carries an equal portion of the load. It also discusses redundancy, where one supply can take over if another fails.
• Potential Anticipation (35 U.S.C. § 102): This reference is relevant to the overall concept of redundant power supplies (claims 1, 9, 14). While it emphasizes current sharing in a balanced load approach (which US7939967 explicitly aims to avoid as "less than optimum efficiency" in its background), it does describe the underlying architecture of multiple power supplies for redundancy. The detection of failure and the capability for one supply to take over could potentially anticipate elements of claims related to the system setup, but not necessarily the specific "standby mode" or the "failing supply providing operating power during transition" features of US7939967.

6. US5675480A — Microprocessor control of parallel power supply systems

• Full Citation: US5675480A, "Microprocessor control of parallel power supply systems" by Ho; Lap C. (Houston, Tex.), assigned to Compaq Computer Corporation.
• Publication/Filing Date: Filed May 29, 1996, published October 7, 1997.
• Brief Description: This patent describes a parallel power supply system controlled by a microprocessor. The system allows for dynamic adjustment of power supply output based on load demand, including bringing additional supplies online or taking them offline. It touches on fault detection and graceful degradation.
• Potential Anticipation (35 U.S.C. § 102): This reference could be relevant to the general control aspects of multiple power supplies, particularly in claims 1, 9, and 14. The "microprocessor control" enables detecting faults and adjusting power supply operation, which can include transitioning between output levels. However, the specific "standby to normal output upon alert of source failure, with the failing supply sustaining power during transition" may not be explicitly taught.

7. US7082042B2 — System and method for power distribution

• Full Citation: US7082042B2, "System and method for power distribution" by Lee; Shih-Wei (Taipei, TW) et al., assigned to Hewlett-Packard Development Company, L.P.
• Publication/Filing Date: Filed December 16, 2003, published July 25, 2006.
• Brief Description: This patent describes a power distribution system with multiple power supply modules and a power control module. It focuses on managing power output based on overall system requirements and optimizing efficiency. It can switch between power supply modules.
• Potential Anticipation (35 U.S.C. § 102): This reference generally covers power distribution with multiple supplies and control mechanisms, which aligns with the broad context of US7939967 (claims 1, 9, 14). The ability to switch between power supply modules could be seen as a form of transitioning. The specific triggers and sustained power during transition would be key for differentiating US7939967.

8. US7368832B2 — Circuit and fault tolerant assembly including such circuit

• Full Citation: US7368832B2, "Circuit and fault tolerant assembly including such circuit" by Kesterson; Robert G. (Maitland, FL) et al., assigned to Mrl Industries.
• Publication/Filing Date: Filed September 30, 2002, published May 6, 2008.
• Brief Description: This patent describes a fault-tolerant assembly, specifically a power supply circuit, designed to continue operation even if a component fails. It uses redundancy at a component level or module level.
• Potential Anticipation (35 U.S.C. § 102): This patent is broadly relevant to the concept of fault tolerance in power supplies (claims 1, 9, 14). However, it focuses more on internal fault tolerance within a single power supply or module rather than the inter-power supply communication, standby/normal modes, and alert-driven transitions between distinct power supplies powered by independent sources as claimed in US7939967.

9. US20080191552A1 — Power supply device and storage control device

• Full Citation: US20080191552A1, "Power supply device and storage control device" by Kato; Osamu (Odawara, JP), assigned to Hitachi, Ltd.
• Publication/Filing Date: Filed February 8, 2007, published August 14, 2008.
• Brief Description: This publication discusses a power supply device with multiple power supply modules and a control unit that monitors their status and switches between them, for instance, when one module becomes faulty, to maintain stable power supply to a load. It also mentions standby modules.
• Potential Anticipation (35 U.S.C. § 102): This reference directly addresses redundant power supplies, monitoring, and switching upon fault detection, including standby modules, which aligns well with claims 1, 9, and 14 of US7939967. The specific mechanism of how the "failing power supply provides operating level energy... during the transitioning" is a critical distinguishing factor for US7939967.

10. US7436950B2 — Apparatus and method for real-time power distribution management

• Full Citation: US7436950B2, "Apparatus and method for real-time power distribution management" by Lim; Beng Hong (Singapore, SG) et al., assigned to Hewlett-Packard Development Company, L.P.
• Publication/Filing Date: Filed July 2, 2003, published October 14, 2008.
• Brief Description: This patent describes a system for managing power distribution in real-time, allowing for efficient allocation of power from multiple sources to various loads based on demand and availability. It can involve switching power supplies on or off.
• Potential Anticipation (35 U.S.C. § 102): This patent covers real-time power management and distribution from multiple sources, which could involve power supplies transitioning between output levels. It shares some high-level concepts with US7939967 (claims 1, 9, 14) regarding managing multiple power supplies. However, its primary focus is on power allocation and efficiency rather than the specific fault-response mechanism of an alert signal from a failing source triggering a standby supply to take over while the failing supply temporarily sustains the load.