Fan controlling circuit
First Claim
Patent Images
1. 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.
1 Assignment
0 Petitions
Accused Products
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.
15 Citations
13 Claims
-
1. 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. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. 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; anda 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. - View Dependent Claims (9, 10, 11, 12, 13)
-
Specification