Fan control circuit with temperature compensation and method of controlling fan
AssigneeEnermax Technology Corporation
InventorsChin-Yun Chang, Chien-Kuei Hsu
Life of this patent
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Abstract
A fan control circuit with temperature compensation includes an on-off unit and a speed adjustment unit. When determining that a loading is greater than or equal to an adjustable start threshold according to a load signal, the on-off unit controls the fan entering a working mode. In the working mode and determining that the loading is less than a speed-adjusting threshold, the on-off unit maintains a speed value of the fan at a first fixed speed. When determining the loading is greater than or equal to the speed-adjusting threshold, the speed adjustment unit adjusts the speed value according to the loading. The speed adjustment unit generates a speed displacement according to a temperature signal to compensate the speed value.
Claims12
A fan control circuit with temperature compensation, comprising:
- an on-off unit coupled to a fan, and the on-off unit configured to receive a load signal corresponding to a loading of a load, the on-off unit comprises:
- a start circuit configured to receive the load signal and a start signal, and
- a switch unit coupled to the start circuit and the fan, and
- a speed adjustment unit coupled to the fan, and the speed adjustment unit configured to receive the load signal and a temperature signal corresponding to a temperature of the load, and an output end of the speed adjustment unit coupled to an output end of the on-off unit and the fan,
- wherein the on-off unit is configured to set an adjustable start threshold, and determine that the loading is greater than or equal to the adjustable start threshold according to the load signal to control the fan entering a working mode;
- in the working mode and when the on-off unit determines that the loading is less than a speed-adjusting threshold, the on-off unit controls the fan entering a fixed-speed mode and maintains a speed value of the fan at a first fixed speed;
- when the speed adjustment unit determines that the loading is greater than or equal to the speed-adjusting threshold, the speed adjustment unit controls the fan entering a speed-adjusting mode, and the speed adjustment unit adjusts the speed value according to the loading;
- the speed adjustment unit generates a speed displacement according to the temperature signal, and provides the speed displacement to compensate the speed value when the fan enters the working mode,
- wherein the start circuit determines whether the loading is greater than or equal to the adjustable start threshold to provide a first control signal according to the load signal and the start signal;
- the switch unit is turned on or turned off by the first control signal to control the fan entering the working mode, and
- wherein when the switch unit is turned on by the first control signal, an input end of the fan receives a working voltage to control the speed value of the fan to be at the first fixed speed, and when a voltage of a speed signal provided by the speed adjustment unit exceeds the working voltage, the speed value of the fan is controlled by the speed signal.
A method of controlling a fan with temperature compensation, comprising steps of:
- realizing a loading of a load according to a load signal, and realizing a temperature of the load according to a temperature signal,
- setting an adjustable start threshold, and determining whether the loading is greater than or equal to the adjustable starting threshold according to the load signal and a starting signal
- determining that the loading is greater than or equal to the adjustable start threshold, and providing a first control signal to control a switch unit to be turned on, so as to control a fan entering a working mode,
- controlling the fan entering a fixed-speed mode, and maintaining a speed value of the fan to be at a first fixed speed when in the working mode and the loading is less than a speed-adjusting threshold,
- controlling the fan entering a speed-adjusting mode, and adjusting the speed value according to the loading when in the working mode and the loading is greater than or equal to the speed-adjusting threshold, and
- setting a speed displacement according to the temperature, and providing the speed displacement to compensate the speed value when the fan enters the working mode,
- when the switch unit is turned on by the first control signal, an input end of the fan receives a working voltage to control the speed value of the fan to be at the first fixed speed, and
- when a voltage of a speed signal exceeds the working voltage, the speed value of the fan is controlled by the speed signal.
Dependencies are inferred from the claim text.