CN201170865Y - Computer fan control circuit - Google Patents

Abstract

The utility model discloses a computer fan control circuit. The computer fan control circuit comprises an activating voltage, a triode, a thermistance, a service voltage, a diode and a fan; wherein, the emitter of the triode is electrically connected with the output end of the activating voltage; the base of the triode is connected with one end of the thermistance; the collector of the triode is respectively connected with the output end of the diode and the input end of the fan; the other end of the thermistance is grounded; the thermistance utilizes the change of temperature to change the resistance value of self as well as the current strength in the circuit in order to change the working state of the triode; the input end of the diode is connected with the service voltage; the output end of the fan is grounded. The computer fan control circuit eliminates the heat generated by the electrified devices of a hibernating or shutdown computer, so that the devices and the chips in the computer can be prevented from being burnt out.

Description

Computer fan control circuit

【Technical field】

The utility model relates to a computer fan control circuit, in particular to a fan control circuit for a computer system in various standby modes.

【Background technique】

With the progress of the electronic information society, a large number of electronic products have flooded into the market, which has accelerated the progress of science and technology. People's life and work are increasingly inseparable from computers. Computers help us process, transmit, and store large amounts of data. With the high speed and high integration of operating pulse, the performance of the CPU configured in the current computer is rapidly improved. However, generally speaking, the higher the performance of the CPU, the more heat it generates when running. Since the computer will also activate the voltage and generate current when it is in the sleep state S3 or the shutdown state S5, many devices in the motherboard will generate some heat, which will burn out some device chips after a long time.

FIG. 1 shows a circuit diagram of a conventional computer fan control circuit.

Please refer to shown in Fig. 1, it is the circuit diagram of conventional computer fan control circuit, this computer fan control circuit comprises: a power supply voltage 10, a fan 20, one end thereof is connected with the power supply voltage 10, and the other end is grounded.

When the computer is in the working state S0, the power supply voltage 10 is connected, and the two ends of the fan 20 are applied with a voltage of 12V, and a current flows through, so that the fan 20 can work normally and eliminate the heat generated by various parts of the computer when the computer is working. During the dormant state S3 or the shutdown state S5, the power supply voltage 10 is cut off and cannot provide voltage to the fan 20, so that the fan 20 cannot work, and the heat generated by the activation voltage in some devices in the computer cannot be eliminated. In this way, some devices and chips in the computer will be burned out after a long time.

In view of this, it is necessary to propose a computer fan control circuit, which can make the fan work normally when the computer is in the dormant state S3 or the shutdown state S5, and eliminates the failure of some devices in the computer in these states. The heat generated during the current flow prevents some devices and chips in the computer from burning out.

【Content of invention】

Therefore, the utility model provides a computer fan control circuit to realize that the fan can also work normally when the computer is in the state of sleep S3 or shutdown S5, so as to prevent some components and chips in the computer from burning out.

In order to achieve the above purpose, the utility model provides a computer fan control circuit, the computer fan control circuit includes: an activation voltage, a triode, a thermistor, a power supply voltage, a diode, a fan, wherein: the triode The emitter is electrically connected to the output terminal of the above activation voltage, the base of the triode is connected to one end of the thermistor, the collector of the triode is connected to the output terminal of the diode and the input terminal of the fan respectively, and the triode is used in the control circuit Whether the current is output; the other end of the thermistor is grounded, and it uses the change of temperature to change its own resistance and at the same time change the size of the current in the circuit to change the working state of the triode; the input end of the diode is connected to the power supply voltage. It is used to prevent the current flowing from the triode from flowing to the supply voltage, and prevent backflow; the negative pole of the fan is grounded.

Specifically, the computer fan control circuit also includes: a capacitor, one end of which is electrically connected to the input end of the fan, and the other end is grounded through the output end of the fan; the above-mentioned transistor is a PNP type transistor; the activation voltage is 5Vsb; The power supply voltage is 10V-16V; the above-mentioned thermistor is a negative temperature coefficient thermistor, and its resistance value becomes smaller as the temperature rises.

When the computer is in the working state S0, the power supply voltage is greater than the activation voltage, so the triode is in the cut-off state, so the voltage at both ends of the fan in the circuit is the power supply voltage to make the fan work normally;

When the computer is in the sleep state S3 or the shutdown state S5, the power supply voltage is 0, and only the activation voltage is left in the circuit to provide voltage, because the activation voltage is greater than the power supply voltage, the triode is in the amplified state, and the two ends of the thermistor have a current. As time increases and the temperature rises, the resistance value of the thermistor decreases, so the current passing through the two ends of the thermistor will increase, so the current flowing to the fan will also increase accordingly. The voltage becomes larger, and then reaches the voltage at which the fan can work, making it work normally.

Compared with the prior art, the computer fan control circuit of the utility model adds a thermistor and a triode so that when the computer is in the dormant state S3 or the shutdown state S5, the fan can also work normally, eliminating the need for some devices in the computer to operate. The heat generated when current is passed through, so that these devices and chips are not easy to be burned out.

【Description of drawings】

FIG. 1 shows a circuit diagram of a conventional computer fan control circuit.

FIG. 2 shows a circuit diagram of the computer fan control circuit of the present invention.

【Detailed ways】

Referring to Fig. 2, it is a circuit diagram of the computer fan control circuit of the present invention.

The computer fan control circuit of the present utility model comprises: an activation voltage 1, a triode 2, a thermistor 3, a power supply voltage 4, a diode 5, a fan 6, and a capacitor 7, wherein:

The activation voltage 1 is 5Vsb;

The emitter of the triode 2 is electrically connected to the output end of the activation voltage 1, the base of the triode 2 is connected to one end of the thermistor 3, and the collector of the triode 2 is connected to the output end of the diode 5 and the input end of the fan 6 respectively. are connected to each other, and the triode 2 is a PNP type triode, which is used to control whether the current in the circuit is output;

The other end of the thermistor 3 is grounded, and it uses the change of temperature to change its own resistance value while changing the size of the current in the circuit to change the working state of the triode 2. The thermistor 3 is a negative temperature coefficient thermistor;

The diode 5 is connected to the power supply voltage 4 at its input (in this embodiment, the power supply voltage 4 is 10V-16V), and the diode 5 is used to prevent the current flowing from the triode 2 from flowing to the power supply voltage 4, so as to prevent backflow;

The negative pole of the fan 6 is grounded;

One end of the capacitor 7 is connected to the input end of the fan 6 , and the other end is grounded through the output end of the fan 6 , and the capacitor 7 is used to stabilize the voltage at both ends of the fan 6 .

In this embodiment, the above-mentioned diode 5 is used to prevent the current flowing from the triode 2 from flowing to the supply voltage 4 when the computer is in the sleep state S3 or the shutdown state S5, and the diode 5 prevents backflow;

When the computer is in the working state S0, the power supply voltage 4 is greater than the activation voltage 1, so that the triode 2 is in a cut-off state, so the voltage at both ends of the fan 6 in the circuit is the power supply voltage 4 to make the fan 6 work normally;

When the computer is in the sleep state S3 or the shutdown state S5, the power supply voltage 4 is 0, and only the activation voltage 1 is left in the circuit to provide voltage, because the activation voltage 1 is 5Vsb greater than the power supply voltage 4, the transistor 2 is in the amplified state, and the thermistor 3 There is current at both ends, and as the temperature increases with time, the resistance value of the thermistor 3 decreases so that the current passing through the two ends of the thermistor 3 will increase, so the current flowing to the fan 6 will also increase accordingly, and the current flowing to the fan 6 will increase accordingly. As the current increases, the voltage across the two ends of the fan 6 becomes larger, and then reaches the working voltage of the fan 6 to make it work normally.

Claims (6)

1. A computer fan control circuit, characterized in that the computer fan control circuit comprises: an activation voltage, a triode, a thermistor, a power supply voltage, a diode, and a fan, wherein: The emitter of the triode is electrically connected to the output end of the activation voltage, the base of the triode is connected to one end of the thermistor, the collector of the triode is connected to the output end of the diode and the input end of the fan respectively, and the triode is used for Whether the current in the control circuit is output; The other end of the thermistor is grounded, which changes its own resistance by changing the temperature and at the same time changes the current in the circuit to change the working state of the triode; The diode, whose input terminal is connected to the power supply voltage, is used to prevent the current flowing from the triode from flowing to the power supply voltage, so as to prevent backflow; the fan, the output terminal of which is grounded; When the computer is in the working state, the power supply voltage is greater than the activation voltage, so the triode is in the cut-off state, so the voltage at both ends of the fan in the circuit is the power supply voltage to make the fan work normally; When the computer is in sleep state or shutdown state, the power supply voltage is 0, and only the activation voltage is left in the circuit to provide voltage, because the activation voltage is greater than the power supply voltage, the triode is in the amplified state, and the thermistor has a current at both ends. As the temperature rises, the resistance value of the thermistor decreases, so the current passing through the thermistor will increase, so the current flowing to the fan will also increase, and the voltage across the fan will change as the current increases. Large, and then reach the voltage that the fan can work, so that it can work normally. 2. The computer fan control circuit according to claim 1, further comprising: the activation voltage is 5Vsb. 3. The computer fan control circuit according to claim 1, further comprising: the power supply voltage is 10V-16V. 4. The computer fan control circuit according to claim 1, characterized in that the computer fan control circuit further comprises: the transistor is a PNP transistor. 5. The computer fan control circuit according to claim 1, further comprising: a capacitor, one end of the capacitor is electrically connected to the input end of the fan, and the other end is grounded through the output end of the fan . 6. The computer fan control circuit according to claim 1, further comprising: the thermistor is a negative temperature coefficient thermistor, and its resistance value becomes smaller as the temperature rises.

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