Fan control method for a computer system based on a time variable rate of current

• US 10,149,407 B2
• Filed: 11/02/2015
• Issued: 12/04/2018
• Est. Priority Date: 06/25/2014
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Chen, Jenseng J S, Chen, Jung-Tai, Chen, Tsung-Yu, Kung, Edward Yu-Chen, Lin, Tzongli, Smith, Bruce A.
• Primary Examiner(s): Ali, Mohammad
• Assistant Examiner(s): Azad, Md
• Application Number:
  US14/929,455
• Publication Number:
  US 20160057889A1
• Time in Patent Office: 1,128 Days
• Field of Search: 700282
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G06F 1/206 comprising thermal management
• CPC Class Codes: H05K 7/20209 Thermal management, e.g. fan control
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A fan control system includes a fan and a target device. The fan control system includes a controller to control the rotation speed of the fan. The controller controls the rotation speed according to a time-variable rate of current consumed by the target device. Particularly, when the time-variable rate of current exceeds a threshold, the controller controls the fan to operate at a maximum rotation speed.

Claims

1. A method comprising:

configuring a computer system with an operating system, a fan in communication with a target device, and a controller connected to the fan;

connecting a detecting circuit to the target device, the circuit detecting a time-variable rate of current consumed by the target device and sending an indicative signal to the controller in response to detection of the time variable rate of current;

managing a rotational speed of the fan with the controller, including adjusting the rotational speed of the fan according to the time-variable rate of current in response to a surge of workload, wherein the adjusting is instantaneous;

controllably driving the fan to operate at a maximum rotation speed through the controller when the operation state is a first predetermined state and the time-variable rate of current exceeds a first predetermined value, wherein the first predetermined state comprises a first power state (PS) mode at least partially defined with a first current consumed by the target device and at least one second PS mode at least partially defined with at least one second current consumed by the target device, wherein the first current is greater than the second current; and

executing a predetermined operation through the operating system when the operation state is a second predetermined state and the time-variable rate of current exceeds a second predetermined value.

2. The method of claim 1, wherein the detecting circuit provides the indicative signal to the operating system.

3. The method of claim 1, wherein the detecting circuit comprises a differentiator based on an operation amplifier.

4. The method of claim 1, wherein the target device includes at least two heterogeneous target devices.

5. The method of claim 1, wherein the indicative signal is provided in form of an interrupt signal to the controller.

6. The method of claim 1, wherein the detecting circuit comprises a differentiator based on an operation amplifier, wherein the differentiator detects the time-variable rate of current.

7. The method of claim 1, further comprising the controller controllably driving the fan with Pulse Width Modulation (PWM) signals.

8. The method of claim 7, further comprising the controller controllably driving the fan with PWM signals of different duty cycles.

9. The method of claim 1, wherein the first PS mode defines the first predetermined value as a threshold value for the time-variable rate of current, the threshold variable associated with driving the fan to operate at a maximum rotation speed, and the second PS mode defines the second predetermined value as a reference value for the time-variable rate of current, the reference value associated with the predetermined operation of waking at least one core of a multi-core processor to absorb at least a portion of an increase in the second current.

10. The method of claim 1, further comprising the controller determining a surge of current consumption and mitigating heat accumulation and associated decrease in service life of at least a portion of the computer system.

11. The method of claim 1, wherein the adjusting the rotational speed of the fan is proactive.