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公开(公告)号:US11862966B2
公开(公告)日:2024-01-02
申请号:US17451520
申请日:2021-10-20
Applicant: Cisco Technology, Inc.
Inventor: Xiqun Zhu , Sung K. Baek
Abstract: According to an embodiment, a surge protector includes a capacitor, a switch, and a first transistor. The capacitor charges based on an input power to the surge protector. The switch turns on when the capacitor is charged to a charge threshold. The surge protector outputs the input power when the switch is turned on. The first transistor turns on when a voltage of the input power exceeds a first input voltage threshold such that the capacitor discharges to below the charge threshold and such that the switch turns off. The surge protector stops outputting the input power when the switch is turned off.
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公开(公告)号:US20230097568A1
公开(公告)日:2023-03-30
申请号:US17484847
申请日:2021-09-24
Applicant: Cisco Technology, Inc.
Inventor: Xiqun Zhu , Sung Kee Baek , Robert Gregory Twiss
Abstract: A method comprises, at a power balancing circuit for three-phase AC power: feeding three power phases to respective loads; measuring power drain on the three power phases by the respective loads; based on measuring, detecting an unbalanced power drain across the three power phases due to a relatively light power drain on one or more lightly loaded power phases and a relatively high power drain on one or more heavily loaded power phases; computing an amount of power to be drained from the one or more lightly loaded power phases and to be fed to the one or more heavily loaded power phases to balance the power drain across the three power phases; and transferring the amount of power from the one or more lightly loaded power phases to the one or more heavily loaded power phases to balance the power drain across the three power phases.
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公开(公告)号:US10473729B2
公开(公告)日:2019-11-12
申请号:US15261860
申请日:2016-09-09
Applicant: Cisco Technology, Inc.
Inventor: Xiqun Zhu , Sung Kee Baek , Robert Gregory Twiss
IPC: G01R31/42 , H02J3/00 , H02J13/00 , G01R19/165 , G01R31/02
Abstract: To reduce the rate at which a false alternating current (“AC”) loss alarming signal is generated, but at the same time detect an actual AC loss situation in a timely manner, the disclosed method describes an AC line power loss detection and active verification method. If the AC line input voltage dips momentarily lower than a standard sine wave amplitude, the AC line may not be considered lost as long as it still has energy to drive a load. The method inserts a momentary load across the AC line and compares the AC line voltage before and after the extra load is applied. If the AC power is present, this extra loading will increase the AC loading current momentarily, but will not affect the AC line voltage. However, if the AC power is lost, such loading will lower the AC line voltage, indicating a loss of power.
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公开(公告)号:US20180074136A1
公开(公告)日:2018-03-15
申请号:US15261860
申请日:2016-09-09
Applicant: Cisco Technology, Inc.
Inventor: Xiqun Zhu , Sung Kee Baek , Robert Gregory Twiss
CPC classification number: G01R31/42 , G01R19/16547 , G01R31/026 , H02J3/00 , H02J13/00
Abstract: To reduce the rate at which a false alternating current (“AC”) loss alarming signal is generated, but at the same time detect an actual AC loss situation in a timely manner, the disclosed method describes an AC line power loss detection and active verification method. If the AC line input voltage dips momentarily lower than a standard sine wave amplitude, the AC line may not be considered lost as long as it still has energy to drive a load. The method inserts a momentary load across the AC line and compares the AC line voltage before and after the extra load is applied. If the AC power is present, this extra loading will increase the AC loading current momentarily, but will not affect the AC line voltage. However, if the AC power is lost, such loading will lower the AC line voltage, indicating a loss of power.
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公开(公告)号:US20230344329A1
公开(公告)日:2023-10-26
申请号:US17724985
申请日:2022-04-20
Applicant: Cisco Technology, Inc.
Inventor: Xiqun Zhu , Sung Kee Baek , Joel Goergen , Doug Paul Arduini , Ruqi Li
IPC: H02M1/00
CPC classification number: H02M1/0048 , H02M1/0043
Abstract: 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.
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公开(公告)号:US11249144B2
公开(公告)日:2022-02-15
申请号:US16901989
申请日:2020-06-15
Applicant: Cisco Technology, Inc.
Inventor: Xiqun Zhu , Sung Kee Baek , Robert Gregory Twiss
Abstract: To reduce the rate at which a false alternating current (“AC”) loss alarming signal is generated, but at the same time detect an actual AC loss situation in a timely manner, the disclosed method describes an AC line power loss detection and active verification method. If the AC line input voltage dips momentarily lower than a standard sine wave amplitude, the AC line may not be considered lost as long as it still has energy to drive a load. The method inserts a momentary load across the AC line and compares the AC line voltage before and after the extra load is applied. If the AC power is present, this extra loading will increase the AC loading current momentarily, but will not affect the AC line voltage. However, if the AC power is lost, such loading will lower the AC line voltage, indicating a loss of power.
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公开(公告)号:US10718822B2
公开(公告)日:2020-07-21
申请号:US16600361
申请日:2019-10-11
Applicant: Cisco Technology, Inc.
Inventor: Xiqun Zhu , Sung Kee Baek , Robert Gregory Twiss
IPC: G01R31/42 , G01R19/165 , G01R31/50 , H02J3/00 , H02J13/00
Abstract: To reduce the rate at which a false alternating current (“AC”) loss alarming signal is generated, but at the same time detect an actual AC loss situation in a timely manner, the disclosed method describes an AC line power loss detection and active verification method. If the AC line input voltage dips momentarily lower than a standard sine wave amplitude, the AC line may not be considered lost as long as it still has energy to drive a load. The method inserts a momentary load across the AC line and compares the AC line voltage before and after the extra load is applied. If the AC power is present, this extra loading will increase the AC loading current momentarily, but will not affect the AC line voltage. However, if the AC power is lost, such loading will lower the AC line voltage, indicating a loss of power.
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公开(公告)号:US11909255B2
公开(公告)日:2024-02-20
申请号:US17702944
申请日:2022-03-24
Applicant: Cisco Technology, Inc.
Inventor: Xiqun Zhu , Sung Kee Baek , Wingo Cheong , Steven Anthony Granzella , Joel Goergen , Charles Calvin Byers
CPC classification number: H02J9/061 , H02J7/00309 , H02J7/00306
Abstract: In one embodiment, a battery backup unit (BBU) cut-off and recharge circuit includes: a first transistor, a power entry connection connected to a main power supply, where power from the power entry connection flows to application circuits for an electronic device, and the first transistor is positioned between a BBU and the power entry connection, and a microcontroller, where the microcontroller is operative to: detect a loss of power from the main power supply, turn on the first transistor to enable the BBU to discharge through the power entry connection to application circuits, detect a status of charge (SOC) for the BBU, and upon detecting that the SOC is under a predefined threshold, set the BBU cut-off and recharge circuit to a lockdown state by turning off the first transistor.
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公开(公告)号:US20230361668A1
公开(公告)日:2023-11-09
申请号:US18353536
申请日:2023-07-17
Applicant: Cisco Technology, Inc.
Inventor: Xiqun Zhu , Sung Kee Baek , Joel Goergen , Doug Paul Arduini , Ruqi Li
IPC: H02M1/00
CPC classification number: H02M1/0048 , H02M1/0043
Abstract: 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.
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公开(公告)号:US20200309861A1
公开(公告)日:2020-10-01
申请号:US16901989
申请日:2020-06-15
Applicant: Cisco Technology, Inc.
Inventor: Xiqun Zhu , Sung Kee Baek , Robert Gregory Twiss
IPC: G01R31/42 , G01R19/165 , G01R31/50 , H02J3/00 , H02J13/00
Abstract: To reduce the rate at which a false alternating current (“AC”) loss alarming signal is generated, but at the same time detect an actual AC loss situation in a timely manner, the disclosed method describes an AC line power loss detection and active verification method. If the AC line input voltage dips momentarily lower than a standard sine wave amplitude, the AC line may not be considered lost as long as it still has energy to drive a load. The method inserts a momentary load across the AC line and compares the AC line voltage before and after the extra load is applied. If the AC power is present, this extra loading will increase the AC loading current momentarily, but will not affect the AC line voltage. However, if the AC power is lost, such loading will lower the AC line voltage, indicating a loss of power.
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