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US 11,212,937 B2Granted
Method and system for preventing or correcting fan reverse rotation during online installation and removal
AssigneeCisco Technology, Inc.
InventorsPaolo Sironi, Emanuele Umberto Giacometti, Rohit Dev Gupta, Joel Richard Goergen
Life of this patent
Estimating the term…
Abstract
In one embodiment, a method includes detecting reverse rotation of a fan inserted into a modular electronic system comprising at least one other fan, wherein the reverse rotation of the fan is caused by a back pressure generated by the other fan rotating in a forward direction, applying current pulses to stop reverse rotation of the inserted fan and start rotation of the fan in a forward direction, and operating all of the fans with rotation in the forward direction.
Claims17
A method comprising:
- detecting reverse rotation of an inserted fan that is inserted into a modular electronic system comprising at least one other fan, wherein said reverse rotation of the inserted fan is caused by a back pressure generated by said at least one other fan rotating in a forward direction;
- applying current pulses to stop said reverse rotation of the inserted fan and start rotation of the inserted fan in said forward direction;
- and
- operating the inserted fan and said at least one other fan with rotation in said forward direction;
- wherein applying said current pulses comprises applying a specified number of the current pulses and checking a rotation direction of the inserted fan.
2 more elements
A modular electronic system comprising:
- an electronic module;
- at least two removable fans for cooling the electronic module;
- and
- a fan controller for controlling a speed of the at least two removable fans and receiving input comprising the speed and a direction of rotation of the at least two removable fans,
- wherein the fan controller is operable upon detecting reverse rotation of one of the at least two removable fans to initiate application of current pulses to said one of the at least two removable fans to stop said reverse rotation of said one of the at least two removable fans;
- and
- wherein the fan controller is configured to initiate application of a specified number of the current pulses to said one of the at least two removable fans if said reverse rotation of said one of the at least two removable fans continues.
4 more elements
A modular electronic system comprising:
- an electronic module;
- at least two removable fans for cooling the electronic module;
- and
- a fan controller for controlling a speed of the at least two removable fans and receiving input comprising the speed and a direction of rotation of the at least two removable fans,
- wherein the fan controller is operable upon detecting reverse rotation of one of the at least two removable fans to initiate application of current pulses to said one of the at least two removable fans to stop said reverse rotation of said one of the at least two removable fans;
- and
- wherein the fan controller is configured to initiate application of lower duty cycle current pulses to said one of the at least two removable fans if said reverse rotation of said one of the at least two removable fans continues to allow electronics to cool down before application of additional current pulses.
4 more elements
A method comprising:
- controlling a fan speed and receiving input comprising the fan speed and a direction of rotation of fans in a modular electronic system;
- detecting reverse rotation of an inserted fan of the fans, wherein the inserted fan is inserted into the modular electronic system;
- applying a specified number of high duty cycle current pulses to stop said reverse rotation of the inserted fan;
- and
- applying a specified number of low duty cycle current pulses if said reverse rotation of the inserted fan continues to allow electronics to cool down before application of additional high duty cycle current pulses.
2 more elements
Dependencies are inferred from the claim text.