Cisco Technology, Inc.

Ruqi Li

Sung Kee Baek

Joel Richard Goergen

Douglas Paul Arduini

Chad M Jones

Jason DeWayne Potterf

Richard Anthony O'Brien

Xiqun Zhu

Doug Paul Arduini

Yang Li

Kan Seto

Michael Grant

Matt Howard

Richard Anthony O′Brien

Techniques are provided to synchronize a remote power switch at a power receiver end of a power cable with a first power switch operation at a power source end of the cable, without any physical or data communication means for synchronization. This process may involve synchronization of a MOSFET-type switch with voltage pulsing at the power source cable end to a MOSFET-type isolation switch at the power receiver cable end to provide (voltage or load) power during the On-time and safety testing for a shock hazard during the Off-time. This method synchronizes switching pulses by sensing and synchronizing on the cable switching voltage transients from the source side. This method also involves blanking the additional switching voltage transients on the cable generated after the synchronized switching begins to maintain proper synchronization. These techniques may be used for a single-pair pulse power cable or with multi-pair multi-phase pulse power cables.

Remote switch synchronization for pulse power and fault managed power (FMP) applications

In one embodiment, a method includes receiving low voltage pulse power from power sourcing equipment at a powered device, synchronizing the powered device with a waveform of the low voltage pulse power received from the power sourcing equipment, and operating the powered device with high voltage pulse power received from the power sourcing equipment.

Initialization and synchronization for pulse power in a network system

A control method improves the efficiency profile of a power supply across a wide range of output loading. The method includes obtaining a measure of output power for a power supply, which includes one or more output modules and an auxiliary power supply. The method determines whether a maximum power rating of the auxiliary power supply is sufficient to provide the measure of output power. Responsive to a determination that the maximum power rating of the auxiliary power supply is sufficient to provide the measure of output power, the controller of the power supply directs the auxiliary power supply to provide the output power.

Modular power supply architecture optimized for flat efficiency across loadings

Techniques are provided for detecting a fault across a pair of lines. Pulse power is applied across the pair of lines. The pulse power comprises alternating pulse on-time intervals and pulse off-time intervals. During a pulse off-time interval, a resistor is connected across the pair of lines and then disconnected when a voltage across the pair of lines reaches a first droop percentage in a first period of time. After disconnecting the resistor, it is determined whether the voltage across the pair of lines droops at least a second droop percentage within a second period of time that begins after the first period of time. Occurrence of a line-to-line fault across the pair of lines is determined when the voltage across the pair of lines droops by at least the second droop percentage or more within the second period of time.

Fault managed power with dynamic and adaptive fault sensor

In one embodiment, an apparatus comprises an input power interface for receiving input power, a power control system for transmitting DC (Direct Current) pulse power on multiple phases over a cable to a plurality of powered devices and verifying cable operation during an off-time of pulses in the DC pulse power, and a cable interface for delivery of the DC pulse power on the multiple phases and data over the cable to the powered devices. A method for transmitting multiple phase pulse power is also disclosed herein.

Multiple phase pulse power in a network communications system

In one embodiment, a method includes identifying at a first powered device in communication with power sourcing equipment, a second powered device in communication with the first powered device, wherein the first powered device is receiving high voltage pulse power from the power sourcing equipment, notifying the power sourcing equipment of the second powered device at the first powered device, and performing a low voltage power initialization at the first powered device with the second powered device before passing the high voltage pulse power to the second powered device.

Embodiments herein describe control circuitry for operating a PFC converter in an AC-DC power supply under light loading conditions. The embodiments herein improve the power factor by identifying an optimized phase offset (&#x3b3;) between an AC reference voltage and an AC reference current used to control the PFC converter. In one embodiment, the control circuitry iteratively changes the phase offset between the reference voltage and current and measures its impact on the power factor. The control circuitry then selects the phase offset that results in the best power factor to use when operating the PFC converter under light loading conditions.

Power factor of AC-DC off-line power supplies under light load condition

In one embodiment, a method includes transmitting from power sourcing equipment, low voltage pulse power to a powered device in a communications network, performing a safety test, enabling high voltage pulse power operation at the power sourcing equipment upon passing the safety test, and transmitting high voltage pulse power from the power sourcing equipment to the powered device. The powered device synchronizes with a waveform of the low voltage pulse power.

In one embodiment, a power apparatus includes a buck converter including a first capacitor, a first inductor and a first switch for connection with a direct current power supply, wherein when the first switch is closed and the buck converter is connected to the direct current power supply, the first capacitor and the first inductor are connected in series to the direct current power supply, a full-bridge inverter including at least four switches including the first switch, a second, third and fourth switch so that the first switch is shared by the inventor and buck converter, the inverter being operative to convert direct current to alternating current by alternating (a) closing the first and fourth switch with the second and third switch open, and (b) closing the second and third switch with the first and fourth switch open, and a transformer to step down an output of the inverter.

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Fremont, CA, United States of America

Ruqi Li