CN100380340C - Temperature detection and control circuit - Google Patents

Abstract

The invention provides a temperature detection and control circuit, which comprises a first voltage division circuit, a second voltage division circuit, a fan rotating speed controller and a comparison circuit. The first voltage divider circuit outputs a first voltage. The second voltage division circuit outputs a second voltage. The second voltage division circuit has a temperature-sensitive electronic element for detecting the temperature of a hardware. The comparison circuit receives and compares the first voltage and the second voltage and outputs the result to the fan rotating speed controller. When the fan speed controller receives the first fan control signal, the fan speed controller maintains the first speed, and when the fan speed controller receives the second fan control signal, the fan speed controller maintains the second speed.

Description

Temperature detection and control circuit

technical field

The present invention relates to a temperature detection and control circuit, and in particular to a temperature detection and control circuit for a computer system.

Background technique

Today's computer systems are getting smaller and smaller, but the computing speed is getting faster and faster. Many components will emit heat under high-speed computing, which will reduce the performance of the computer system and even damage the system. Therefore, how to dissipate heat from a computer system is a very important issue.

The display card in the computer system is easy to generate heat because it needs to process high-speed image calculations. In the past, display cards used temperature detection chips. Although detailed temperature measurements can be made, the results are often inaccurate and expensive. In terms of temperature control, in the past, PWM (pulse width modulation) IC was used to control the speed of the fan, but this method is more complicated and expensive. In addition, there are usually graphics processing unit (graphic processing unit) power circuits and memory power circuits on the display card. In the past, Nvidia and ATI display cards would control the input voltage of the graphics processing unit power circuit, but did not control the memory power circuit. For input voltage control.

Therefore, there is a great need for a cheap and simple temperature detection and control circuit to solve the above problems.

Contents of the invention

Therefore, the purpose of the present invention is to provide a temperature detection and control circuit, which can be realized by simple and cheap hardware components.

Another object of the present invention is to provide a temperature detection and control circuit, which can inform the user whether the temperature is within the normal temperature, so as to protect the display card from overheating.

Another object of the present invention is to provide a temperature detection and control circuit, wherein the fan speed controller can meet the requirements of heat dissipation performance and quietness.

Another object of the present invention is to provide a temperature detection and control circuit, wherein the fan speed controller only uses transistors and resistors, and uses the principle of voltage division to control the fan in two stages (high speed or low speed (or stop)) , can achieve the control of noise, but it has greatly reduced the cost of control.

Another object of the present invention is to provide a temperature detection and control circuit, which can increase the voltage of the graphics processing unit power circuit and the memory power circuit under the operating system, so that the chip has a higher overclocking capability, and can also Do voltage reduction to reduce the overall heat generation of the system.

According to the above object of the present invention, a temperature detection and control circuit is proposed. According to a preferred embodiment of the present invention, the temperature detection and control circuit includes a first voltage divider circuit, a second voltage divider circuit, a fan speed controller and a comparison circuit. The first voltage dividing circuit receives a power supply and outputs a first voltage. The second voltage dividing circuit receives the power and outputs a second voltage. The second voltage dividing circuit has a temperature-sensing electronic component for detecting the temperature of a hardware. When the temperature of the hardware changes, the impedance of the temperature-sensing electronic component changes, so that the second voltage changes.

The comparison circuit receives the first voltage and the second voltage. When the second voltage is greater than the first voltage, the comparison circuit outputs a third voltage. When the second voltage is less than the first voltage, the comparison circuit outputs a fourth voltage. The third voltage can be converted into a first fan control signal, and the fourth voltage can be converted into a second fan control signal.

The fan speed controller is used to control a fan to dissipate heat from the hardware. When the fan speed controller receives the third voltage or the first fan control signal, the fan speed controller maintains the first speed. When receiving the fourth voltage or the second fan control signal, the fan speed controller maintains the second speed.

In one embodiment, the fan speed controller includes a transistor and a resistor. The source of the transistor is grounded, the drain is electrically connected to the fan, and the gate receives the first fan control signal or the second fan control signal. The first end of the resistor is electrically connected to the drain of the transistor, and the second end is grounded.

Wherein, when the gate of the transistor receives the first fan control signal, the transistor is turned on, and the source of the transistor outputs the first current. When the gate of the transistor receives the second fan control signal, the transistor is turned off, and the second end of the resistor outputs a second current.

According to the object of the present invention, a temperature detection and control circuit is provided for detecting and controlling the temperature of a display card. According to a preferred embodiment of the present invention, the temperature detection and control circuit includes a first voltage divider circuit, a second voltage divider circuit and a comparison circuit.

The first voltage dividing circuit receives a power supply and outputs a first voltage. The second voltage dividing circuit receives the power and outputs a second voltage. The second voltage dividing circuit has a temperature sensing electronic element for detecting the temperature of a display card. When the temperature of the display card changes, the resistance of the temperature-sensing electronic element changes, so that the second voltage changes.

A comparison circuit receives the first voltage and the second voltage. When the second voltage is greater than the first voltage, the comparison circuit outputs a third voltage. When the second voltage is less than the first voltage, the comparison circuit outputs a fourth voltage.

The display card includes a memory power circuit, and the output of the comparison circuit is converted into a memory voltage control signal and sent to a gate of a transistor. The drain of the transistor is electrically connected to the memory power supply circuit through a resistor.

The present invention has at least the following advantages, wherein each embodiment may have one or more advantages. The temperature detection and control circuit of the present invention can be realized by simple and cheap hardware components. The temperature detection and control circuit of the present invention can inform the user whether the temperature is within the normal temperature, so as to protect the display card from overheating. The fan speed controller of the present invention can take into account heat dissipation efficiency and quietness requirements. The fan speed controller of the present invention only uses transistors and resistors, and uses the principle of voltage division to control the fan in two stages (high speed or low speed (or stop)), which can achieve noise control, but it has greatly reduced control cost. The temperature detection and control circuit of the present invention can increase the voltage of the power supply circuit of the graphics processing unit and the memory power supply circuit under the operating system, so that the chip has a higher overclocking capability, and can also be used to lower the voltage, so that the system Overall heat generation is reduced.

Description of drawings

Fig. 1 depicts an example of the action flow chart of the temperature detection and control circuit of the present invention;

FIG. 2 illustrates a circuit diagram of an embodiment of a temperature detection circuit;

FIG. 3 illustrates a circuit diagram of an embodiment of a temperature detection circuit;

FIG. 4 illustrates an embodiment of a fan speed controller;

FIG. 5 illustrates another embodiment of the fan speed controller; and

FIG. 6 illustrates an embodiment of the graphics processing unit power circuit and the input voltage control circuit of the memory power circuit.

Detailed ways

FIG. 1 shows an example flow chart of the temperature detection and control circuit of the present invention. First, the temperature of a hardware (such as a display card) is detected (step 104). Next, it is determined to allow the user to adjust or utilize an application software (application) to automatically adjust the temperature of the display card (step 106). Next, use the speed of a fan to control the temperature of the display card (step 102 ) or adjust the voltage of a graphics processing unit power circuit (GPU, graphic processing unit) and a memory (memory) (step 108 ).

FIG. 2 is a circuit diagram of an embodiment of the temperature detection circuit. The first voltage divider circuit 201 receives a power source 204 and outputs a first voltage 216 . The second voltage dividing circuit 203 receives the power source 204 and outputs a second voltage 214 . The second voltage dividing circuit 203 has a temperature sensing electronic element 212 for detecting the temperature of a hardware. The temperature-sensing electronic component 212 is placed close to the hardware to be tested, such as the back of a graphics processing unit (GPU), or close to a heat source. When the temperature of the hardware changes, the resistance of the temperature-sensing electronic element 212 changes, so that the second voltage 214 changes.

The comparison circuit 218 receives the first voltage 216 and the second voltage 214 . When the second voltage 214 is greater than the first voltage 216 , the comparison circuit 218 outputs a third voltage. When the second voltage 214 is less than the first voltage 216 , the comparison circuit 218 outputs a fourth voltage. For example, the comparator circuit 218 can input a piece of hardware (such as a display card) through a general purpose input/output pin (GPIO 1, general purpose input output) 202, and the hardware converts the third voltage into the first fan control signal (or converts the first fan control signal) The four voltages are converted into the second fan control signal), and then output to a fan speed controller through another general-purpose input and output pin GPIO 2.

In one embodiment, the first voltage dividing circuit 201 includes a first resistor 206 and a second resistor 210 . One end 222 of the first resistor 206 is electrically connected to the power source 204 . The first terminal 224 of the second resistor 210 is electrically connected to the first resistor 206 , and the second terminal of the second resistor 210 is grounded. Wherein the first terminal 224 of the second resistor 210 outputs the first voltage.

In one embodiment, the second voltage dividing circuit 203 includes a third resistor 208 and a temperature-sensing electronic element 212 . One end 226 of the third resistor 208 is connected to the power source 204 . The first terminal 228 of the temperature-sensing electronic component 212 is electrically connected to the third resistor 208 , and the second terminal of the temperature-sensing electronic component 212 is electrically connected to the ground. The first terminal 228 of the temperature-sensing electronic element 212 outputs a second voltage. The temperature-sensing electronic component 212 is, for example, a thermistor. The comparison circuit 218 is, for example, an operational amplifier. In this embodiment, when the hardware temperature rises, the resistance of the thermistor rises, and the third voltage will be greater than the fourth voltage.

In one embodiment, when the comparison circuit 218 outputs the third voltage, the temperature detection circuit displays an abnormal temperature signal on a display. When the comparison circuit 218 outputs the fourth voltage, the temperature detection circuit displays a normal temperature signal on a display. The user can know whether the temperature of the display card is overheated through the display, so as to protect the display card. The temperature detection circuit only displays two conditions: normal temperature (pass) or high temperature (fail), which are displayed digitally without displaying accurate temperature values. In this way, the function of temperature detection can also be achieved, but the cost can be greatly reduced. When the fan speed increases and the hardware cannot return to normal temperature, it can automatically shut down to protect the hardware (display card).

This embodiment can also indirectly detect whether the fan is faulty or not. When the fan is running at full speed but cannot cool down the hardware (such as the graphics processing unit (GPU)), it indicates a problem with the fan. At this time, it can be automatically shut down to protect the graphics processing unit.

FIG. 3 shows a circuit diagram of an embodiment of the temperature detection circuit. FIG. 3 is substantially the same as FIG. 1 , except that a potential adjustment circuit 342 and a potential inversion circuit 344 are added in FIG. 3 . Because GPIO1 302 has a certain input voltage specification, when the output voltage of comparison circuit 328 does not meet the input voltage specification, some circuits must be used to adjust the output voltage of comparison circuit 328 to match the input voltage specification of GPIO 1 302. For example, when the output of the comparison circuit 328 is 12 volts, it needs to be converted to 3.3 volts.

The potential adjustment circuit 342 has a resistor 346 , a resistor 348 and a resistor 350 . The potential inversion circuit 344 has a transistor 356 , a resistor 352 , and a resistor 354 . By adjusting the parameters of these resistors and transistors, users can adjust the voltage to match the input voltage specifications of GPI0302.

When the potential adjustment circuit 342 is used, it is not necessary to use the potential inversion circuit 344 . But when the potential inversion circuit 344 is used, the resistor 346 and the resistor 350 are still required.

FIG. 4 illustrates an embodiment of a fan speed controller. The fan speed controller 400 is used to control the fan 404 to dissipate heat from a piece of hardware. When the fan speed controller 400 receives the first fan control signal, the fan speed controller 400 maintains the first speed. When the fan speed controller 400 receives the second fan control signal, the fan speed controller 400 maintains the second speed.

When the fan speed is fast, the heat dissipation capability is good, but the noise is relatively large. When the fan speed is low, the cooling capacity is not good, but the noise is less. Therefore, the design of the fan speed controller must make a trade-off between heat dissipation capability and noise.

The fan speed controller 400 includes a transistor 408 and a resistor 406 . The source (source) 416 of the transistor 408 is electrically connected to the ground, the drain (drain) 414 of the transistor 408 is electrically connected to the fan 404, and the gate (gate) 412 of the transistor 408 receives the first fan control signal or the second fan. control signal.

The first end of the resistor 406 is electrically connected to the drain 414 of the transistor 408 , and the second end is electrically connected to the ground. When the gate 412 of the transistor 408 receives the first fan control signal, the transistor 408 is turned on. The drain 414 of the transistor 408 generates the first current.

When the gate 412 of the transistor 408 receives the second fan control signal, the transistor 408 is turned off, and the resistor 406 generates the second current. At this time, the voltage division relationship between the fan 404 and the resistor 406 changes, the divided voltage received by the fan 404 becomes smaller, and the electric power (power, P=I*V) received by the fan 404 decreases, so the fan speed decreases.

FIG. 5 illustrates another embodiment of the fan speed controller. The drain of the transistor 516 is electrically connected to the fan 514 , the source of the transistor 516 is electrically connected to the power source 504 , and the gate of the transistor 516 receives the first fan control signal or the second fan control signal. The first end 510 of the resistor 508 is electrically connected to the source of the transistor 516 , and the second end 512 of the resistor 508 is electrically connected to the drain of the transistor 516 .

When the gate 520 of the transistor 516 receives the first fan control signal, the transistor 516 is turned off, and the resistor 508 outputs the first current. At this time, the voltage division relationship between the fan 514 and the resistor 508 changes, the divided voltage received by the fan 514 becomes smaller, and the electric power (power, P=I*V) received by the fan 514 decreases, so the fan speed becomes slower. When the gate of the transistor 516 receives the second fan control signal, the transistor 516 is turned on, and the drain of the transistor 516 outputs the second current.

FIG. 6 illustrates an embodiment of the graphics processing unit power circuit and the input voltage control circuit of the memory power circuit. The display card has a graphics processing unit power circuit (GPU power circuit) 604 and a memory power circuit (memory power circuit) 602 . Raising the voltage of the graphics processing unit power supply circuit 604 and the memory power supply circuit 602 can make the chip have higher overclocking capability. Of course, reducing the voltage can reduce the heat generation of the system.

The output of the comparison circuit (such as 218 in FIG. 2 ) is converted into a graphics processing unit voltage control signal, which is sent to the gate 628 of the first transistor 620 through a GPIO 3 606. The drain of the first transistor 628 is electrically connected to the graphics processing unit power circuit 604 via the first resistor 616 . The output of the comparison circuit is converted into a memory voltage control signal, which is sent to the gate of the second transistor 622 through the GPIO 3 606, and the drain of the second transistor 622 is electrically connected to the memory power supply circuit 602 through the second resistor 618. In this embodiment, the graphics processing unit voltage control signal and the memory voltage control signal have the same source.

In one embodiment, a soft start circuit 624 can be placed between the output of the comparison circuit and the gate of the first transistor 620 . The soft start circuit 624 includes a resistor 642 and a capacitor 644 . Similarly, another soft-start circuit 626 can also be placed between the output of the comparison circuit and the gate of the second transistor 622 . The soft start circuit 626 includes a resistor 638 and a capacitor 640 .

The circuit of Fig. 6 can make the transistor 622 turn on through 6PIO 606, and then make the resistor 618 and the voltage control resistor of the memory power supply circuit 602 parallel to change the voltage of the memory power supply circuit 602, also make the transistor 620 turn on, and then make the resistor 616 and the The voltage control resistors of the graphics processing unit power supply circuit 604 are connected in parallel to change the voltage of the graphics processing unit power supply circuit 604 . Conversely, the operation can also be reversed, using the GPIO 606 to turn off the transistors 622 and 620 to change the voltage of the graphics processing unit power supply circuit 604 and the memory power supply circuit 602. Adding the soft-start circuits 626 and 624 can avoid situations such as failure and crash of the operating system (such as Microsoft Window) caused by the rapid rise and fall of the voltage.

The temperature detection and control circuit of the present invention can be realized by simple and cheap hardware components. The temperature detection and control circuit of the present invention can inform the user whether the temperature is within the normal temperature, so as to protect the display card from overheating. The fan speed controller of the present invention can take into account heat dissipation efficiency and quietness requirements. The fan speed controller of the present invention only uses transistors and resistors, and uses the principle of voltage division to control the fan in two stages (high speed or low speed (or stop)), which can achieve noise control, but it has greatly reduced control cost. The temperature detection and control circuit of the present invention can increase the voltage of the graphics processing unit power circuit and the memory power circuit under the operating system, so that the chip has a higher overclocking capability, and can also be used for voltage reduction, so that the system Overall heat generation is reduced. Although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be defined by the scope of the appended patent application.

Claims (13)

1. A temperature detection and control circuit, comprising: The first voltage divider circuit receives a power supply and outputs a first voltage; The second voltage dividing circuit receives the power and outputs a second voltage. The second voltage dividing circuit has a temperature-sensing electronic component for detecting the temperature of a display card. When the temperature of the display card changes, the temperature-sensing electronic component Impedance changes, so that the second voltage changes, wherein the display card includes a graphics processing unit power supply circuit and a memory power supply circuit, the output of the comparison circuit is converted into a memory voltage control signal and sent to the gate of a first transistor, the The drain of the first transistor is electrically connected to the graphics processing unit power supply circuit through a first resistor, and the output of the comparison circuit is also converted into a memory voltage control signal and sent to the gate of a second transistor. The drain is electrically connected to the memory power supply circuit through a second resistor; A comparison circuit, receiving the first voltage and the second voltage, when the second voltage is greater than the first voltage, the comparison circuit outputs the third voltage, and when the second voltage is less than the first voltage, the comparison circuit The circuit outputs the fourth voltage. 2. The temperature detection and control circuit according to claim 1, wherein the first voltage divider circuit comprises: a first resistor, one end of which is electrically connected to the power source; and The first end of the second resistor is electrically connected to the first resistor, and the second end is grounded, wherein the first end of the second resistor outputs the first voltage. 3. The temperature detection and control circuit according to claim 1, wherein the second voltage divider circuit comprises: A third resistor, one end of which is connected to the power supply, wherein the first end of the temperature-sensing electronic component is electrically connected to the third resistor, the second end of the temperature-sensing electronic component is electrically connected to the ground, and the first end of the temperature-sensing electronic component is electrically connected to the third resistor. One end outputs the second voltage. 4. The temperature detection and control circuit as claimed in claim 1, wherein the temperature-sensing electronic component is a thermistor. 5. The temperature detection and control circuit as claimed in claim 1, wherein the comparison circuit is an operational amplifier. 6. The temperature detection and control circuit according to claim 1, further comprising a fan speed controller, the fan speed controller controls a fan to dissipate heat from the display card, the third voltage corresponds to the first Fan control signal, the fourth voltage corresponds to the second fan control signal, when receiving the first fan control signal, the fan speed controller maintains the first speed, when receiving the second fan control signal, the fan speed controller maintains the first speed Two speeds. 7. The temperature detection and control circuit according to claim 6, wherein the fan speed controller comprises: a transistor, the source of which is grounded, the drain is electrically connected to the fan, and the gate receives the first fan control signal or the second fan control signal; and a resistor, the first terminal is electrically connected to the drain of the transistor, and the second terminal is grounded; Wherein when the gate of the transistor receives the first fan control signal, the transistor is turned on, the source of the transistor outputs the first current, and when the gate of the transistor receives the second fan control signal, the transistor is turned off, The second end of the resistor outputs a second current. 8. The temperature detection and control circuit according to claim 6, wherein the fan speed controller comprises: a transistor, the drain of which is electrically connected to the fan, the source of which is electrically connected to the power supply, and the gate receives the first fan control signal or the second fan control signal; and a resistor, the first end is electrically connected to the source of the transistor, and the second end is electrically connected to the drain of the transistor; Wherein when the gate of the transistor receives the first fan control signal, the transistor is turned off, and the resistor outputs the first current; when the gate of the transistor receives the second fan control signal, the transistor is turned on, and the transistor The drain outputs the second current. 9. The temperature detection and control circuit according to claim 1, wherein when the comparison circuit outputs the third voltage, the temperature detection and control circuit displays an abnormal temperature signal on a display, and when the comparison circuit When outputting the fourth voltage, the temperature detection and control circuit displays a normal temperature signal on a display. 10. The temperature detection and control circuit as claimed in claim 1, further comprising a soft start circuit disposed between the output of the comparison circuit and the gate of the first transistor. 11. The temperature detection and control circuit as claimed in claim 10, wherein the soft start circuit comprises a resistor and a capacitor. 12. The temperature detection and control circuit as claimed in claim 1, further comprising a soft start circuit disposed between the output of the comparison circuit and the gate of the second transistor. 13. The temperature detection and control circuit as claimed in claim 12, wherein the soft start circuit comprises a resistor and a capacitor.

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