Fan controlling circuit
AssigneesHONG FU JIN PRECISION INDUSTRY (ShenZhen) CO., LTD., Hon Hai Precision Industry Co., Ltd.
InventorsChin-Wen Yeh, Zhi-Jian Peng, Hai-Shan Sun
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Abstract
A fan controlling circuit for detecting rotational speed of a fan, includes a comparison circuit and a controlling chipset. The comparison circuit receives a rotational speed signal from the fan at one input terminal, a reference voltage at another input terminal, and outputs a filtered rotational speed signal at an output terminal. The controlling chipset receives the filtered rotational speed signal, and outputs control signals to control the rotational speed of the fan.
Claims13
A fan controlling circuit for detecting a rotational speed of a fan, comprising:
- a comparison circuit configured for receiving a rotational speed signal from the fan at one input terminal, a reference voltage at another input terminal, and outputting a filtered rotational speed signal at an output terminal;
- and
- a controlling chipset for receiving the filtered rotational speed signal, and outputting a control signal to control the rotational speed of the fan;
- wherein the comparison circuit comprises a comparator, a first resistor, and a second resistor;
- the inverting input terminal of the comparator is configured to receive the rotational speed signal;
- the non-inverting input terminal of the comparator is configured to receive the reference voltage via the first resistor;
- the output terminal of the comparator is coupled to the controlling chipset to output the filtered rotational speed signal, and is coupled to the non-inverting input terminal of the comparator via the second resistor.
A fan controlling circuit for detecting a rotational speed of a fan, comprising:
- a comparison circuit configured for receiving a rotational speed signal from the fan at one input terminal, a reference voltage at another input terminal, and outputting a filtered rotational speed signal at an output terminal;
- a controlling chipset for receiving the filtered rotational speed signal, and outputting a control signal;
- wherein the comparison circuit comprises a comparator, a first resistor, and a second resistor;
- the inverting input terminal of the comparator is configured to receive the rotational speed signal;
- the non-inverting input terminal of the comparator is configured to receive the reference voltage via the first resistor;
- the output terminal of the comparator is coupled to the controlling chipset, and is coupled to the non-inverting input terminal of the comparator via the second resistor;
- and
- a super input/output controller configured for receiving the control signals, and outputting a pulse width modulation signal to control the rotational speed of the fan.
Dependencies are inferred from the claim text.