201104256 六、發明說明： 【發明所屬之技術領域*】 [0001] 本發明係關於z種風扇類型檢測及調速系統’尤指—種 可檢測風扇的類璀並控制風扇的轉速的系統。 [先前技術】 [0002] 隨著電腦技術的不斷發展，各種發熱元件特別是中央處 理器（Central Processing Unit，CPU)頻率的不斷 提高，相應地其工作時所產生的熱量也不斷增多，為了 及時將熱量充分散發，一般會在中央處理器上増加風扇 等散熱裝置。 [0003] 習知兩種常用的風扇，一種是3引腳風扇，它的3個叼腳 分別是接地引腳、電源引腳和感測引腳。另一種是4引腳 風扇，它比3引腳風扇多出一個控制引腳。主機板上也對 應4引腳風扇提供了一4端插座，插座的4個端分別為接地 端、電源端、感測端和控制端’其既可以插接3弓丨腳風扇 也可以插接4引腳風扇。若4f丨蜗1夙扇_入此插座之後， 則在電源端會提供一恒定電壓(如+ 12V)，在控制端由 控制晶片提供變化的脈寬調變（Pulse Width Module- tion，PWM)訊號，4引腳風扇的轉速會隨著控制端提供 的PWM訊號的工作週期的變化而變化。但如果將3引腳風 扇插到此插座上時，則因為電源端仍提供恒定電壓，由 於3引腳風扇沒有控制引腳，使得其轉速始終不變，不能 自動根據發熱元件的溫度變化而改變轉速。 【發明内容】 [0004] 鑒於以上内容，有必要提供一種風扇類型檢測及調速系 098125519 表單編號A0101 第4頁/共16頁 0982043658-0 201104256 統，旎夠自動檢測不同風扇的類型，並根據檢測結果選 擇不同的控制方式控制風扇的轉速。 [0005] ❹ Ο 種風扇類型檢測及調速系統，包括—ΒI〇s、第一及第 二電源、一控制晶片、一開關電路、一積分電路及一控 制電路，該控制晶片分別與該開關電路、該積分電路及 一風扇插座相連，該開關電路還與該控制電路相連，該 積分電路還與該第一電源及該控制電路相連，該控制電 路還與該第二電源及該風扇插座相連，該BI〇s控制該控 希J BS片使得該開關電路載.止，該第«電源提供的電壓透 過该積分電路積分後輸出一積分電壓訊號提供給該控制 電路，該控制電路根據該積分電壓訊號控制該第二電源 輸出一恒定電壓給插有一風扇的風扇插座的電源端，該 控制晶片先後輸出第一及第二工作週期的pWM訊號傳送給 該風扇插座的控制端，並分別測得該風扇在該第一及第 二工作週期的PWM訊號下的第一及第二轉速，若該風扇的 第一及第二轉速的比值約等於該第一及第二工作週期的 比值，則推斷該風扇為4引腳的風扇，若該風扇的第一及 第二轉速大致相等，則推斷該風扇為3引腳的風扇，若該 風扇為3引腳的風扇’該BIOS控制控制晶片使得開關電路 導通，該控制晶片輸出隨溫度而變化的PWM訊號使得該第 一電源提供的電壓透過該積分電路積分後輸出積分電壓 訊號提供給該控制電路’該控制電路根據該積分電壓控 制該第二電源輸出一變化的電壓給風扇插座的電源端以 控制該3引腳風扇的榉速。 [0006] 本發明風扇類型檢測及調速系統透過該控制晶片先後輸 098125519 表單編號A0101 第5頁/共16頁 0982043658-0 201104256 出第一及第二工作週期的PWM訊號傳送給該風扇插座的控 制端，並比較風扇在該第一及第二工作週期的PWM訊號下 的第一及第二轉速來確定風扇的類型。還透過控制電路 輸出變化的電壓控制3引腳風扇的轉速。並且該風扇類型 檢測及調速系統結構簡單、成本較低、工作穩定。 [0007] [0008] [0009] 098125519 【實施方式】 請參閱圖1 ’本發明風扇類型檢測及調速系統1 0用於自動 檢測插接於電腦主機板的風扇插座108上的風扇（例如3 引腳或4引腳的風扇）的類型’並根據風扇的類型控制 ：. 風扇的轉速，其較佳實施方式包括一基本輸入輸出系統(Basic Input/Output System，BIOS) 60、一控制 晶片70、第一電源80、第二電源9〇、一開關電路j 〇〇、 一積分電路102及一控制電路1〇6。控制晶片7〇可以為 Super I/O晶片 '平台控制器（piatf〇rm c〇ntr〇Uer Hub，PCH)等。 BI OS 6 0可控制控制晶片7 〇輸出高電平或低電平。控制 晶片70分別與開關電路1〇〇、積分電路1〇2及風扇插座 108相連。開關電路1〇〇還與控制電路1〇6相連積分電 路1〇2還與第一電源80及控制電路1〇6相連。控制電路 106還與第二電源9〇及風扇插座1〇8相連。 田風扇類型檢測及調速系統1G檢測插接於風扇插座⑽上 賴扇的類型時，制如下的檢測方法：BIGS 6G控制控 制b曰片70輸出控制訊號使得開關電路1〇〇導通，第一電源 8〇提供的電_過積分電路⑽積分後輸出—積分電壓^ 號提供給控制電路刚，控制電路刚根據此積分電麼訊 第6頁/共16頁 表單編號A0101 0982043658-0 201104256 ❹ [0010] Ο [0011] 號控制第二電源90輸出一恒定電壓（如12ν)給插有風扇 的風扇插座10 8的電源端。然後ΒI 〇s 60控制控制晶片7〇 先後輸出兩相差較大的第一及第二工作週期的pwM訊號傳 送給風扇插座108的控制端，並分別測得風扇在第一及第 二工作週期的爾訊號下的第-及第二轉速，若風扇的第 一及第二轉速的比值大致等於第一及第二工作週期的比 值，則推斷插接於風扇插座108上的風扇為4引腳的風扇 ，若風扇的第一及第二轉速近似相等，則推斷插接於風 扇插座108上的風扇為3引腳的風扇》例如當mm訊號的工 作週期為100%時’風扇的轉速為3〇〇〇轉/秒，訊號的 工作週期為20%時’風扇的轉速為31⑽轉/秒，則可以推 斷此風扇為3引腳的風扇。反之，若pwjk的工作週期為2〇% 時，風扇的轉速為700轉/秒，則可以推斷此風扇為4引腳 的風扇。 旦透過接收的轉速訊號判定插接於風扇插座1〇8上的風 扇的類型為4引腳風扇’則會維持原先輸出的控制訊號不 變，使開關電路10 0.仍保持導通。此時，隨著發熱元件溫 度變化，控制晶片70會發送工作週期變化的PWM訊號給風 扇插座108的控制端，自動改變風扇的轉速。由於4引腳 風扇内部已經集成PWM訊號控制線路，這裡不再贅述。 若判定為3引腳的風扇，則本發明風扇類型檢測及調速系 統W會對其進行轉速控制。其具體控制過程如下： Bl〇S 60控制控制晶片70輸出控制訊號使得開關電路1〇〇 截止，控制晶片70輸出隨溫度而變化的PWM訊號使得第一 電源80提供的電壓透過積分電路1〇2積分後輸出積分電壓 098125519 表單編號A0101 第7頁/共16頁 0982043658-0 [0012] 201104256 訊號提供給控制電路l〇6，控制電路1〇6根據此積分電壓 控制第二電源90輸出一變化的電壓給風扇插座丨的電源 端以控制風扇的轉速。 [0013] 請再參閱圖2，開關電路100包括一場效應電晶體Q1。場 效應電晶體Q1的閘極連接控制晶片70的控制訊號的輸出 端GPIO，源極接地，汲極連接控制電路1〇6。在本實施方 式中，場效應電晶體Q1為一NM0S場效應電晶體，在其他 實施方式中，場效應電晶體Q丨也可以為其他類型的電開 關，例如PNP型電晶體等。 [0014] 積分電路102包括兩電阻Ri ' R2及一電容C1。電阻ri連 接於第一電源80及控制晶片7〇的PWM訊號輸出端P1之間 ，電阻R2的一端連接控制晶片7〇的PWM訊號輪出端P1， 電阻R2的另一端透過電容ci接地，還連接控制電路106。 在本實施方式中，第一電源8〇最佳為5V直流電源。 [0015] 控制電路106包括一放大器U1、》場政應電晶體Q2、兩電 阻R3及R4、-電容C2。放大器ϋΐ的反相輸入端連接該電 容C1及該電阻R2之間的節點，放大器U1的同相輸入端透 過電阻R3接地’還連接場效應電晶體qi的汲極，還透過 電阻R4連接風扇插座108的電源端VCC，放大器U1的輸出 端OUT連接該場效應電晶體Q2的閘極，場效應電晶體Q2的 源極連接第二電源90，場效應電晶體Q2的汲極連接風扇 插座108的電源端VCC，風扇插座1〇8的電源端VCC還透過 電容C2接地’風扇插座108的接地端GND接地，風扇插座 108的控制端CTL連接控制晶片70的PWM訊號輸出端P1， 風扇插座108的偵測端SEN連接控制晶片的偵測引腳S1。 098125519 表單編號A0101 第8頁/共16頁 0982043658-0 201104256 [0016] [0017] Ο ο [0018] 在本實施方式中，第二電源9 0最佳為1 2 V的直流電源，場 效應電晶體Q2為一PMOS場效應電晶體。在其他實施方式 中，場效應電晶體Q2也可採用其他類型的電開關，例如 ΝΡΝ型電晶體等。在其他實施方式中，電容C2也可以省去 下面舉例說明該風扇類型檢測及調速系統10檢測及控制 風扇轉速的工作過程： BIOS 60控制控制晶片70在其控制訊號的輸出端GPIO輸 出高電平（如3V)的修制滅號，漆效應電晶體Q1導通’ 第一電源80提φ的電壓透過電阻R2及電容C1積分後輸出 —積分電壓提供給放大器的反相輪八端，放大器W的 輪出端OUT輸出低電平（如〇V)，使得場效應電晶體Q2導 通，從而第二電源90輸出一恒定電壓（如118V)給風扇 插座108的電源端VCC。然後控制晶片7〇的PWM訊號輸出 端pl輪出PWM訊號的工作週期為1〇〇%，若測得的風扇的 轉迷為3000轉/秒，改變PW1訊號的工作週期為2〇%時， 右測侍的風扇的轉速為3100轉/秒，則可以推斷此風扇為 3弓丨腳風扇。反之，改變PWM訊號的工作週期為2〇%時，若 '】知的風扇的轉速為7 0 〇轉/秒，則可以推斷此風扇為4引 腳風扇。 右檢測的風扇為4引腳風扇，貝，丨BI0S 6〇控制控制晶片7〇 在其控制訊號的輸出端GPI0輸出的控制訊號仍保持高電 平，控制晶片70會發送工作週期變化的pffM訊號給風扇插 座108的控制端CTL，自動改變4引腳風扇的轉速。 098125519201104256 VI. Description of the Invention: [Technical Field of the Invention] [0001] The present invention relates to a z-type fan type detection and speed control system, particularly a system that detects the type of fan and controls the rotational speed of the fan. [Prior Art] [0002] With the continuous development of computer technology, the frequency of various heating elements, especially the Central Processing Unit (CPU), continues to increase, and accordingly the amount of heat generated during operation increases. The heat is fully dissipated, and a heat sink such as a fan is generally added to the central processing unit. [0003] Two commonly used fans are known, one is a 3-pin fan, and its three legs are a ground pin, a power pin, and a sense pin. The other is a 4-pin fan that has one more control pin than a 3-pin fan. The 4-pin fan is also provided with a 4-terminal socket on the motherboard. The four ends of the socket are the grounding terminal, the power terminal, the sensing terminal and the control terminal. They can be plugged into a 3-legged fan or plugged in. 4-pin fan. If the 4f 夙 夙 1 夙 fan enters the socket, a constant voltage (such as + 12V) is provided at the power supply terminal, and the pulse width modulation (PWM) is provided by the control chip at Signal, the speed of the 4-pin fan will change with the duty cycle of the PWM signal provided by the control terminal. However, if a 3-pin fan is plugged into this socket, since the power supply still provides a constant voltage, since the 3-pin fan has no control pin, its rotation speed is always constant and cannot be automatically changed according to the temperature change of the heating element. Rotating speed. SUMMARY OF THE INVENTION [0004] In view of the above, it is necessary to provide a fan type detection and speed control system 098125519 Form No. A0101 Page 4 / Total 16 pages 0984043658-0 201104256 system, enough to automatically detect the type of different fans, and according to The test results select different control methods to control the fan speed. [0005] 风扇 a fan type detection and speed control system, comprising: ΒI〇s, first and second power sources, a control chip, a switch circuit, an integration circuit and a control circuit, the control chip and the switch respectively The circuit, the integrating circuit and a fan socket are connected, the switch circuit is further connected to the control circuit, the integrating circuit is further connected to the first power source and the control circuit, and the control circuit is further connected to the second power source and the fan socket And controlling, by the BI〇s, the control circuit, so that the voltage provided by the first power supply is integrated by the integration circuit, and an integrated voltage signal is outputted to the control circuit, and the control circuit is based on the integral The voltage signal controls the second power source to output a constant voltage to the power terminal of the fan socket in which the fan is inserted, and the control chip outputs the pWM signals of the first and second duty cycles to the control end of the fan socket, and respectively measured The first and second rotational speeds of the fan under the PWM signals of the first and second duty cycles, if the ratio of the first and second rotational speeds of the fan is approximately The ratio of the first and second duty cycles estimates that the fan is a 4-pin fan. If the first and second rotational speeds of the fan are substantially equal, it is inferred that the fan is a 3-pin fan, if the fan is a 3-pin fan's BIOS controls the control chip to turn on the switching circuit. The control chip outputs a PWM signal that varies with temperature so that the voltage supplied by the first power source is integrated by the integrating circuit, and the integrated voltage signal is output to the control circuit. The control circuit controls the second power source to output a varying voltage to the power terminal of the fan socket according to the integrated voltage to control the idle speed of the 3-pin fan. [0006] The fan type detection and speed control system of the present invention successively transmits 098125519 through the control chip. Form No. A0101 Page 5 / Total 16 pages 0984243658-0 201104256 The PWM signals of the first and second duty cycles are transmitted to the fan socket. The control terminal compares the first and second rotational speeds of the fan under the PWM signals of the first and second duty cycles to determine the type of the fan. The 3-pin fan speed is also controlled by the control circuit outputting a varying voltage. Moreover, the fan type detection and speed control system has a simple structure, low cost, and stable operation. [0007] [0009] [0009] 098125519 [Embodiment] Please refer to FIG. 1 'The fan type detecting and speed regulating system 10 of the present invention is used for automatically detecting a fan plugged into a fan socket 108 of a computer motherboard (for example, 3) The type of the pin or the 4-pin fan is controlled according to the type of the fan: the speed of the fan, the preferred embodiment of which includes a basic input/output system (BIOS) 60, a control chip 70 The first power source 80, the second power source 9〇, a switching circuit j 〇〇, an integrating circuit 102 and a control circuit 1〇6. The control chip 7 can be a Super I/O chip 'platform controller (piatf〇rm c〇ntr〇Uer Hub, PCH) or the like. BI OS 6 0 controls the control chip 7 〇 output high or low. The control chip 70 is connected to the switching circuit 1A, the integrating circuit 1〇2, and the fan socket 108, respectively. The switching circuit 1 is also connected to the control circuit 1〇6, and the integrating circuit 1〇2 is also connected to the first power source 80 and the control circuit 1〇6. The control circuit 106 is also connected to the second power source 9A and the fan socket 1A8. When the field fan type detection and speed control system 1G detects the type of fan attached to the fan socket (10), the following detection method is adopted: BIGS 6G control control b 70 70 output control signal makes the switch circuit 1 〇〇 conduction, first The power supply provided by the power supply 8 积分 is integrated and the output is integrated. The integrated voltage ^ is supplied to the control circuit. The control circuit is just based on the integrated power. Page 6 of 16 Form No. A0101 0982043658-0 201104256 ❹ [ 0010] Ο [0011] The second power source 90 is controlled to output a constant voltage (eg, 12 ν) to the power terminal of the fan socket 10 8 in which the fan is inserted. Then, the 控制I 〇s 60 control control chip 7 输出 successively outputs the pwM signals of the first and second duty cycles with two phase differences are transmitted to the control end of the fan socket 108, and respectively measures the fan in the first and second duty cycles. The first and second rotational speeds under the signal, if the ratio of the first and second rotational speeds of the fan is substantially equal to the ratio of the first and second duty cycles, it is estimated that the fan plugged into the fan socket 108 is 4-pin. Fan, if the first and second speeds of the fan are approximately equal, it is estimated that the fan plugged into the fan socket 108 is a 3-pin fan. For example, when the duty cycle of the mm signal is 100%, the fan speed is 3〇. 〇〇 / / sec, when the signal's duty cycle is 20%, 'the fan's speed is 31 (10) rev / sec, then it can be inferred that this fan is a 3-pin fan. Conversely, if the duty cycle of pwjk is 2〇% and the fan speed is 700 rev/sec, it can be inferred that the fan is a 4-pin fan. When the type of the fan plugged into the fan socket 1〇8 is determined to be a 4-pin fan by the received rotational speed signal, the control signal of the original output remains unchanged, so that the switch circuit 10 0 remains conductive. At this time, as the temperature of the heating element changes, the control chip 70 transmits a PWM signal with a duty cycle change to the control terminal of the fan socket 108, and automatically changes the rotation speed of the fan. Since the 4-pin fan has integrated PWM signal control circuitry inside, it will not be described here. If it is determined that it is a 3-pin fan, the fan type detecting and speed regulating system W of the present invention controls the rotation speed thereof. The specific control process is as follows: The Bl〇S 60 control control chip 70 outputs a control signal such that the switching circuit 1〇〇 is turned off, and the control chip 70 outputs a PWM signal that changes with temperature so that the voltage supplied from the first power source 80 passes through the integrating circuit 1〇2. After integration, the integrated voltage is output 098125519. Form No. A0101 Page 7 / Total 16 pages 0984043658-0 [0012] The signal is supplied to the control circuit 106, and the control circuit 1〇6 controls the second power supply 90 to output a change according to the integrated voltage. The voltage is applied to the power supply end of the fan socket to control the speed of the fan. [0013] Referring again to FIG. 2, the switching circuit 100 includes a field effect transistor Q1. The gate of the field effect transistor Q1 is connected to the output terminal GPIO of the control signal of the control chip 70, the source is grounded, and the drain is connected to the control circuit 1〇6. In the present embodiment, the field effect transistor Q1 is an NM0S field effect transistor. In other embodiments, the field effect transistor Q丨 can also be other types of electrical switches, such as PNP type transistors. [0014] The integrating circuit 102 includes two resistors Ri' R2 and a capacitor C1. The resistor ri is connected between the first power source 80 and the PWM signal output terminal P1 of the control chip 7〇. One end of the resistor R2 is connected to the PWM signal wheel terminal P1 of the control chip 7〇, and the other end of the resistor R2 is grounded through the capacitor ci. The control circuit 106 is connected. In the present embodiment, the first power source 8 is preferably a 5V DC power source. [0015] The control circuit 106 includes an amplifier U1, a field transistor Q2, two resistors R3 and R4, and a capacitor C2. The inverting input terminal of the amplifier 连接 is connected to the node between the capacitor C1 and the resistor R2, and the non-inverting input terminal of the amplifier U1 is grounded through the resistor R3. The anode of the field effect transistor qi is also connected, and the fan socket 108 is also connected through the resistor R4. The power terminal VCC, the output terminal OUT of the amplifier U1 is connected to the gate of the field effect transistor Q2, the source of the field effect transistor Q2 is connected to the second power source 90, and the drain of the field effect transistor Q2 is connected to the power source of the fan socket 108. The VCC of the fan socket 1〇8 is also grounded through the capacitor C2. The ground terminal GND of the fan socket 108 is grounded. The control terminal CTL of the fan socket 108 is connected to the PWM signal output terminal P1 of the control chip 70, and the fan socket 108 is detected. The measuring terminal SEN is connected to the detecting pin S1 of the control chip. 098125519 Form No. A0101 Page 8 / Total 16 Page 0982043658-0 201104256 [0017] In the present embodiment, the second power source 9 0 is preferably a DC power supply of 12 V, field effect electric Crystal Q2 is a PMOS field effect transistor. In other embodiments, field effect transistor Q2 can also employ other types of electrical switches, such as germanium transistors. In other embodiments, the capacitor C2 can also omit the following operation of the fan type detection and speed control system 10 for detecting and controlling the fan speed: The BIOS 60 controls the control chip 70 to output high power at the output of the control signal GPIO. Flat (such as 3V) repair and kill, varnish transistor Q1 is turned on 'The first power supply 80 φ voltage through the resistor R2 and the capacitor C1 integrated output - the integrated voltage is supplied to the amplifier's reverse wheel eight-end, amplifier W The output terminal OUT outputs a low level (e.g., 〇V), causing the field effect transistor Q2 to be turned on, so that the second power source 90 outputs a constant voltage (e.g., 118V) to the power supply terminal VCC of the fan socket 108. Then, the duty cycle of the PWM signal output terminal pl of the control chip 7 is 10%, and if the measured fan is 3,000 rpm, the duty cycle of the PW1 signal is changed to 2〇%. The speed of the right-handed fan is 3100 rev / sec, then it can be inferred that this fan is a 3-legged fan. Conversely, when the duty cycle of the PWM signal is changed to 2〇%, if the fan speed of the fan is 7 0 rpm, it can be inferred that the fan is a 4-pin fan. The right detection fan is a 4-pin fan, and the control signal output from the control terminal GPI0 of the control signal chip 7 is still high, and the control chip 70 sends a pffM signal with a duty cycle change. The control terminal CTL of the fan socket 108 automatically changes the rotational speed of the 4-pin fan. 098125519
表單蝙號A010I 第9頁/共16頁 0982043658-0 201104256 [0019]若檢測的風扇為3引腳風扇，則BI〇s 60控制控制晶片70 在其控制訊號的輸出端GP 1〇輸出的控制訊號變為低電平 ，場效應電晶體Q1截止，當控制晶片7〇輸出隨溫度而變 化的離散的數位PWM訊號的工作週期為10%時，第一電源 80提供的電壓透過電阻R2及電容C1積分後輸出線性平滑 的積分電壓訊號較小（如1.7伏特），然後輸入至該放大 器U1的反相輸入端，該放大器U1的輸出端OUT輸出的電壓 較大（如11. 2伏特），則該場效應電晶體Q2的閘極和源 極之間的電壓差較小，該場效應電晶體Q2導通程度較小 ’則第二電源90透過譎場效應電晶體Q2後輸出給風扇的 電壓較小（如5.8伏特），從而使得風扇保持低速運轉。 若控制晶片70輸出的離散的數位PWM訊號的工作週期較大 (如80%)，第一電源80提供的電壓透過電阻R2及電容 C1積分後輸出線性平滑的積分電壓訊號也較大（如10.2 伏特），然後輸入至該放大器υι的反相輸入端’該放大 器U1的輸出端OUT輸出的電壓與PWM訊號的工作週期為 10%時相比較小（如1Θ.1伏邊）’則ά場效應電晶體Q2 的閘極和源極之間的電壓差教大’該場效應電晶體Q2導 通程度較大，則第二電源90透過該場效應電晶體Q2後輸 出給風扇的電壓較高（如丨1· 3伏特）’從而使得風扇保 持高速運轉。 [〇〇20] 本發明風扇類型檢測及調速系統10能自動檢測到風扇的 類型 '，並根據檢測結果選擇不同的控制方式控制風扇的 轉速，並且該風扇類型檢測及調速系統結構簡單 '成本 較低、工作穩定。 098125519 表單編號Α0101 第10頁/共16頁 0932043658-0 201104256 [0021]综上所述，本發明符合發明專利要件，爰依法提出專利 申請。惟，以上所述者僅為本發明之較佳實施例，舉凡 “本案技β之人士 ’在爰依本發明精神所作之等效修 飾或變化，皆應涵蓋於以下之申請專利範圍内。^ 【圖式簡單說明】 剛®1係本Μ風扇類型檢測及調速祕的較佳實施方式連 接一風扇插座的方框圖。 〇 【主要元件符號說明】 [0023] 圖2係圖1的電路圖。 風扇類型檢測 及調速系統 —'~—- 10 BIOS 60 控制晶片 --— 70 第一電源 80 第二電源 --—-- 90 開關電路 _ - 100 積分電路 ----~~_ 102 控制電路 106 風扇插座 108 場效應電晶體 Ql、Q2 放大器 U1 ------^ 電容 Cl、C2 電阻 R1-R4 ------1 0982043658-0 098125519 表單編號Α0101 第11頁/共16頁Form bat number A010I Page 9/16 page 0982043658-0 201104256 [0019] If the detected fan is a 3-pin fan, BI〇s 60 controls the control chip 70 at the output of its control signal GP 1〇 output control When the signal is low, the field effect transistor Q1 is turned off. When the duty cycle of the discrete digital PWM signal whose output of the control chip 7 is changed with temperature is 10%, the voltage supplied from the first power source 80 is transmitted through the resistor R2 and the capacitor. After C1 integration, the linear smooth integrated voltage signal is small (such as 1.7 volts), and then input to the inverting input terminal of the amplifier U1. The output voltage of the output terminal OUT of the amplifier U1 is relatively large (such as 11.2 volts). The voltage difference between the gate and the source of the field effect transistor Q2 is small, and the field effect transistor Q2 is less conductive. The voltage that the second power source 90 transmits to the fan after passing through the field effect transistor Q2. Smaller (such as 5.8 volts), so that the fan keeps running at low speed. If the duty cycle of the discrete digital PWM signal outputted by the control chip 70 is large (for example, 80%), the voltage supplied by the first power supply 80 is integrated through the resistor R2 and the capacitor C1, and the linear smooth integrated voltage signal is also large (for example, 10.2). Volt), then input to the inverting input of the amplifier 'ι's output of the output terminal OUT of the amplifier U1 is smaller than when the duty cycle of the PWM signal is 10% (such as 1Θ.1 volt). The voltage difference between the gate and the source of the effect transistor Q2 is large. The field effect transistor Q2 has a large degree of conduction, and the second power source 90 transmits the voltage to the fan after passing through the field effect transistor Q2. Such as 丨1·3 volts)' so that the fan keeps running at high speed. [〇〇20] The fan type detection and speed control system 10 of the present invention can automatically detect the type of the fan, and select different control modes to control the fan speed according to the detection result, and the fan type detection and speed control system has a simple structure. Low cost and stable work. 098125519 Form No. Α0101 Page 10 of 16 0932043658-0 201104256 [0021] In summary, the present invention complies with the requirements of the invention patent, and patents are filed according to law. However, the above description is only the preferred embodiment of the present invention, and equivalent modifications or variations made by the "person of the present invention" in the spirit of the present invention should be included in the following claims. [Simple diagram of the diagram] A block diagram of a preferred embodiment of the fan type detection and speed control of the Gang® 1 system is connected to a fan socket. [Main component symbol description] [0023] FIG. 2 is a circuit diagram of FIG. Type detection and speed control system—'~-- 10 BIOS 60 control chip--- 70 first power supply 80 second power supply----- 90 switch circuit _ - 100 integration circuit----~~_ 102 control circuit 106 Fan socket 108 Field effect transistor Ql, Q2 Amplifier U1 ------^ Capacitor Cl, C2 Resistor R1-R4 ------1 0982043658-0 098125519 Form number Α0101 Page 11 of 16