556472 玖、發明說明 【發明所屬之技術領域】 本發明係關於一種應用在電源系統或電源供應器的散 熱風扇驅動模組，尤指一種可隨系統的散熱需求增加而方 便擴充驅動的風扇數量，並可使風扇更易於啓動、且可減 少能量消耗、風扇軸承承受應力，進而延長其使用壽命之 散熱風扇驅動模組。 【先前技術】 由於各種電腦設備、儀器之構造日趨精密，對於電源 供應的品質要求相對提高。譬如，有愈來愈多的儀器設備 不容許電源無預警的中斷供應，在該等供電標準要求下， 不斷電電源系統（UPS)即應運而生。其在市電中斷時，可即 時的切換而改由不斷電電源系統持續供應電源。然而，如 前揭所述，當設備儀器愈精密，其對電源供應可靠度的要 求相對愈高，因此，在單機運作可能無法確保不斷電電源 系統之穩定性時，即必須考慮多機並聯運作。並且並聯的 組數係視系統要求的不同而有所差異。 再者，電源系統及電源供應器主要是電源間的轉換電 路，以提供各種設備中電路之不同的電壓或電流電源需求 ，在運作時，由於提供的能量大於一般電路，因此因效率 問題而產生的熱，就必須做妥善的散熱處理，才能使電源 轉換電路正常的工作，而風扇係經常運用在此種場合的散 熱裝置，有關於風扇的驅動與控制，目前有許多已知技術 556472 問世，包括利用PWM脈寬調變電路驅動並控制風扇轉速， 並由風扇驅動電路檢出一風扇轉速信號，以供判斷風扇是 否卡死或作爲調整轉速之依據。其目的無非爲使散熱風扇 的運轉更臻穩定順暢。對於電源系統及電源供應器而言， 溫度爲攸關其運轉能否正常的重要環境因素，對於散熱風 扇驅動品質的要求自然相對愈高。惟既有電源系統及電源 供應器的散熱風扇均由獨立的驅動電路所控制，其意味著 當散熱風扇因電源系統或電源供應器設計的容量增加所致 之散熱需求增加而必須擴充時，即必須重新其驅動電路的 配置，此對於電源系統及電源供應器的供應業者而言，即 無法因應不同的需求，而機動地配置散熱風扇的驅動電路 ，更遑論因應風扇及其驅動電路數量的增加，進一步考量 其運轉的穩定性與工作效率。 故由前述可知，既有電源系統及電源供應器之散熱風 扇驅動電路係隨單機配置，無法因應不同的需求，而作彈 性的設計變化，並同時顧慮到設計容易、管理容易以及品 質穩定，對於業者而言存在諸多困擾，故有待進一步檢討 ，並謀求可行的解決方案。 【發明內容】 因此，本發明主要目的即在提供一種可隨系統的散熱 需求增加而方便擴充驅動風扇數量，同時可使風扇更易於 啓動、且可減少能量消耗/風扇軸承承受應力，進而延長 其使用壽命之散熱風扇驅動模組。 556472 爲達成則述目的採取的主要技術手段係令bu述驅動模 組設爲一單體，該單體上至少包括一驅動電路，該驅動電 路係受外部的脈寬調變電路控制，其輸出端連接至少一組 風扇，並由脈寬調變電路調整輸出脈波信號的寬度，改變 風扇轉速；又驅動電路進一步對連接風扇加入一初始的直 流電壓，使連接風扇更易於啓動，並降低其電流量。 前述的驅動電路主要由一開關電晶體與至少一驅動電 晶體組成；其中，開關電晶體基極透過一電阻連接至脈寬 調變電路的輸出端，其射極則透過驅動電晶體連接風扇； 該驅動電晶體於集、射極間並聯有一電阻與一稽納二極體 ;而前述風扇即連接於一直流電壓源與驅動電晶體的射極 間； 在前述電路設計下，因驅動電晶體的集、射極間設有 一稽納二極體，故連接的直流風扇而言，在啓動時的初始 狀態已加入一直流電壓，藉此可使風扇啓動時降低其電流 量，並在一般狀態下穩定運轉，同時可降低對風扇軸承的 應力，延長使用壽命。 前述驅動電路進一步包括一轉速檢出電路，其輸入端 係連接驅動電路的輸出端，用以供判斷風扇是否有卡死狀 況。 前述驅動電路與轉速檢出電路間的節點上拉出一設定 共用轉速檢出電路端點，當多個驅動模組並聯使用時，可 將各驅動模組之此點連接在一起，則並聯之模組可共用一 組前述之轉速檢出電路，以簡化外部系統配合之電路。 556472 前述單體爲一電路板’該電路板上於至少一邊緣上設 有複數端子，各複數端子係分別與電路板上各電路的輸入 、輸出端或連接節點連接，以便插接至外部控制系統所設 的對應連接器；或者作爲一個電路板模組，直接插接或銲 接在其他電路板上，藉由前述的模組式設計，可依實際需 求增加或減少驅動模組及散熱風扇之數量。 【實施方式】 如第一圖所示，係本發明散熱風扇驅動模組一較佳實 施例的外觀示意圖，其將風扇驅動電路及其他相關電路、 元件建構於一電路板（1 0 0 )上，該電路板（1 0 0 ) 在至少一邊緣上設有複數個端子（1 0 1 )〜（1 0 8 ) ，以構成一模組單體；其中，各個端子（1 0 1 )〜（1 0 8 )並分別與電路板（1 0 0 )上各個電路的輸入、輸 出端或連接節點連接，以便經由端子（1 〇 1 )〜（1 〇 8 )輸入控制信號或輸出檢知信號，至於端子（1 〇 1 ) 〜（1 0 8 )係供對應插接至一外部控制系統的連接介面 ，或者作爲一個電路板（PCB)模組，直接插接或銲接在其他 電路板上，以透過連接介面與外部控制系統、散熱風扇及 其他狀態檢知電路構成連線，以便由外部控制系統透過驅 動模組驅動散熱風扇，並由驅動模組本身及其他的狀態檢 知電路檢知風扇是否正常運轉、電源系統或電源供應器的 溫度及其輕重載狀況，供外部控制系統據以調節散熱風扇 的轉速，而有效提升散熱效率。 556472 有關前述驅動模組在電路板（1 〇 ο )上所設的電路 構造請參閱第二圖所示，其至少包括一驅動電路（1 〇) ，該驅動電路（1 0 )係受外部控制系統中的脈寬調變電 路（圖中未示）控制，其輸出端連接至少一組風扇，並由 脈寬調變電路調整輸出脈波信號的寬度，改變風扇轉速； 該驅動電路（1 0 )主要由一開關電晶體（1 1 )與 至少一驅動電晶體（1 2 ) ( 1 3 )組成，於本實施例中 ，該驅動電晶體（1 2 )( 1 3 )爲兩個；其中，開關電 晶體（1 1 )基極連接一電阻R1，又在電阻R1另端構成 一風扇速度控制端（FANSPD)，與端子（1 〇 6 )連接，供 輸入脈寬可變的脈波信號，其射極則分別連接兩驅動電晶 體（1 2 ) ( 1 3 )的基極，兩驅動電晶體（1 2 ) ( 1 3 )分別於集、射極間並聯有一電阻R6、R12與一稽納二 極體ZD1、ZD2，又分別於集極上構成一風扇連接端點 FAN1、FAN2，其分別連接電路板（1 〇 〇 )上的端子（1 0 1 ) ( 1 0 2 )，供連接被驅動的風扇； 由於前述驅動電晶體（1 2 )( 1 3 )的集、射極間 設有一稽納二極體ZD1、ZD2，故對於連接的直流風扇，在 在啓動前，即由稽納二極體ZD1、ZD2賦予一 9〜12伏特的 直流電壓，藉此可使風扇啓動時降低其電流量。有關該設 計的其他作用與功效，容後詳述之。 又，前述驅動電路（1 0 )進一步與一轉速檢出電路 (1 4 )連接’該轉速檢出電路（1 4 )輸入端係分別透 過一逆向二極體Dl、D2與驅動電路（1 〇 )的兩驅動電晶 556472 體（1 2 ) ( 1 3 )集極連接，用以判斷風扇是否有卡死 狀況。又轉速檢出電路（1 4 )係由一電晶體（1 5 )及 若干電阻R7〜R10所組成，其中電晶體（1 5 )的集極上拉 出一風扇卡死檢知端FANCLK，且連接電路板（1 0 0 ) 上的端子（1 0 7 )連接，供外部控制系統據以檢知風扇 是否有卡死（LOCK)狀況。 除前述線路外，該驅動電路（1 0 )與轉速檢出電路 (1 4 )間的節點上拉出一驅動模組並聯時用之設定共用 轉速檢出電路端點PARALLEL，其連接電路板（1 0 0 ) 上的端子（1 0 8 )，當多個驅動模組並聯使用時，可將 各驅動模組之此點連接在一起，則並聯之模組可共用前述 之同一轉速檢出電路，以簡化外部系統配合之電路。 又前述驅動電路（1 0 )的接地GND1、GND2係分別 連接至電路板（1 0 0 )上的端子（1 0 3 )( 1 0 4 ) ，以作爲共同接地點。 經上述說明可看出本發明驅動模組之具體電路構造， 其進一步的工作原理詳如以下所述： 請參閱第三圖所示，係前述驅動電路（1 0 )的局部 電路，主要揭示其中一驅動電晶體（1 2 )、該驅動電晶 體（1 2 )集、射極間連接的電阻R6、稽納二極體ZD1及 其集極上連接的風扇F1。如圖左所示的波形圖，係假設輸 入至驅動電晶體（1 2 )基極的脈波信號，由於驅動電晶 體（1 2 )集、射極間設有稽納二極體ZD1，故在驅動電 晶體（1 2 )關斷時集極上將加上一直流電壓，使得風扇 10 556472 兩端的電壓波形如圖右所示。 又請參閱第四圖所示，其揭示第三圖中驅動電晶體（ 1 2 )不導通時之狀態，直流電壓源VCC係經電阻R6及 稽納二極體ZD1到地，此時在風扇F1與接地端GND1間即 存在一直流電壓。 當驅動電晶體（1 2 )導通時（如第五圖所示），直 流電壓源VCC係經驅動電晶體（1 2 )到地，故直流電壓 送入風扇F1使其開始運轉，由於啓動前已存在一直流電壓 ，故可有效減少風扇F1啓動時的電流量，從而風扇軸承在 啓動時所遭受的應力亦相對較小，故可延長其工作壽命， 且在一般工作狀態下其運轉將更爲順暢。 又前述驅動電路（1 0 )中每一驅動電晶體（1 2 ) 係連接並驅動一風扇，惟亦可同時連接並驅動多組風扇， 如第六圖所示，即揭露有多個風扇驅動模組同時驅動多組 散熱風扇F1〜Fn之實施態樣。在此實施態樣下，將多個風 扇驅動模組之設定共用轉速檢出電路端點PARALLEL連接 在一起，如此外部控制系統只要透過其中一個模組的風扇 卡死檢知端FANCLK，就可據以檢知多組風扇中是否有風 扇卡死（LOCK)狀況。 由於前述驅動模組係受控於外部的脈寬調變電路，既 使用脈寬調變電路控制轉速，則其可進一步考量其他參數 ，作爲調整風扇轉速之參考，如第二圖揭示有一溫度檢知 電路（2 0 )，主要用來檢知電源系統或電源供應器的溫 度，當電源系統或電源供應器溫度高時，顯示散熱需求提 556472 高’脈寬調變電路可透過驅動模組調升風扇轉速，以進一 步加強散熱效果。當系統溫度低時，顯示散熱需求降低， 脈寬調變電路則透過驅動模組調降風扇轉速，使散熱風扇 之工作更具效率。 又控制風扇轉速的另一參考因素爲負載的輕重狀況， 當電源系統或電源供應器重載時，對散熱需求應相對較高 ’故可由脈寬調變電路透過驅動模組調升風扇轉速以加強 散熱。當系統爲輕載時，則散熱需求相對較低，故脈寬調 變電路透過驅動模組調降風扇轉速，以達減少電力消耗之 目的。 故由上述可知，本發明主要係將電源系統或電源供應 器中使用的散熱風扇驅動電路予以模組化，在模組化設計 T ’可視電源系統或電源供應器的散熱需求方便地擴充驅 動模組及散熱風扇，對於業者而言，可依不同的系統規格 迅速且輕易完成散熱系統的配置，由此可見，本發明相較 方令傳統獨立式的散熱風扇驅動電路已具備顯著功效增進， 故已兼具產業上利用性、新穎性與進步性，並符合發明專 利要件，爰依法提起申請。 【圖式簡單說明】 (一）圖式部分 第一圖··係本發明一較佳實施例之外觀示意圖。 第一圖：係本發明一較佳實施例之電路圖。 胃ΞΒΙ :係本發明一較佳實施例之局部電路及輸入/輸出 12 556472 信號示意圖。 第四圖：係本發明一較佳實施例之局部電路及其工作狀態 示意圖。（電晶體截止） 胃£圖：係本發明一較佳實施例之局部電路及其工作狀態 不思圖。（電晶體導通） 第六圖：係本發明又一較佳實施例之局部電路示意圖。 (〜）元件代表符號 (1〇)驅動電路 （11)開關電晶體 (1 2 ) ( 1 3 )驅動電晶體 (1 4 )信號檢出電路 （1 5 )電晶體 (2 0 )溫度檢知電路 (1 0 〇 )電路板 （1 0 1 )〜（1 0 8 )端子556472 发明 Description of the invention [Technical field to which the invention belongs] The present invention relates to a cooling fan driving module applied to a power supply system or a power supply, and more particularly to a fan that can be easily expanded and driven as the heat dissipation requirement of the system increases. A cooling fan drive module that makes it easier to start the fan, reduces energy consumption, and bears stress on the fan bearings, thereby extending its life. [Previous technology] As the structure of various computer equipment and instruments becomes more and more sophisticated, the quality requirements for power supply are relatively increased. For example, there are more and more instruments and equipment that do not allow the power supply to be interrupted without warning. Under the requirements of these power supply standards, a uninterruptible power supply system (UPS) was born. When the utility power is interrupted, it can be switched immediately and replaced by a continuous power supply system to continuously supply power. However, as mentioned earlier, when the equipment is more precise, the requirements for power supply reliability are relatively higher. Therefore, when the stand-alone operation may not ensure the stability of the uninterruptible power supply system, it is necessary to consider the parallel connection of multiple machines. Operation. And the number of parallel groups depends on the system requirements. Moreover, the power supply system and power supply are mainly conversion circuits between power supplies to provide different voltage or current power requirements for the circuits in various equipment. During operation, the energy provided is greater than that of general circuits, which results from efficiency issues. In order to make the power conversion circuit work normally, the fan must be properly cooled, and the fan is often used as a heat sink for this occasion. There are many known technologies 556472 about the driving and control of the fan. The method includes using a PWM pulse width modulation circuit to drive and control the fan speed, and a fan speed signal is detected by the fan drive circuit for judging whether the fan is stuck or as a basis for adjusting the speed. The purpose is nothing more than to make the cooling fan run more stable and smooth. For power systems and power supplies, temperature is an important environmental factor that determines whether they can operate normally, and the requirements for the driving quality of cooling fans are naturally higher. However, the cooling fans of the existing power system and power supply are controlled by independent driving circuits, which means that when the cooling fan must be expanded due to the increased cooling demand due to the increased capacity of the power system or power supply design, that is, The configuration of the driving circuit must be re-configured. For suppliers of power supply systems and power supplies, it is not possible to respond to different needs and to configure the driving circuit of the cooling fan motor, let alone to increase the number of fans and driving circuits. , Further consider the stability and efficiency of its operation. Therefore, from the foregoing, it can be known that the cooling fan drive circuit of the existing power supply system and power supply is configured with a single machine, and it cannot be flexibly designed to respond to different needs. At the same time, it is considered that the design is easy, the management is easy, and the quality is stable. There are many problems for the industry, so it needs further review and a feasible solution is sought. [Summary of the Invention] Therefore, the main purpose of the present invention is to provide a method that can facilitate the expansion of the number of driving fans as the heat dissipation requirement of the system increases, at the same time, it can make the fans easier to start, and can reduce energy consumption / stress on the fan bearings, thereby extending its Cooling fan drive module with long service life. 556472 The main technical method adopted to achieve the stated purpose is to make the drive module a single unit, which includes at least a drive circuit, which is controlled by an external pulse width modulation circuit. The output end is connected to at least one group of fans, and the width of the output pulse signal is adjusted by the pulse width modulation circuit to change the fan speed; the driving circuit further adds an initial DC voltage to the connected fan to make it easier for the connected fan to start, and Reduce its amount of current. The aforementioned driving circuit is mainly composed of a switching transistor and at least one driving transistor. The base of the switching transistor is connected to the output of the PWM circuit through a resistor, and the emitter is connected to the fan through the driving transistor. ; The driving transistor has a resistor in parallel between the collector and the emitter, and an audit diode; the aforementioned fan is connected between the DC voltage source and the emitter of the driving transistor; under the aforementioned circuit design, A crystal diode is set between the collector and the emitter of the crystal. Therefore, for the connected DC fan, a DC voltage has been added to the initial state at startup, so that the fan can reduce its current when it starts, and in general Stable operation under the condition, at the same time, it can reduce the stress on the fan bearing and prolong the service life. The driving circuit further includes a rotation speed detecting circuit, and its input terminal is connected to the output terminal of the driving circuit for judging whether the fan is stuck. The node between the drive circuit and the speed detection circuit is pulled out to set a common speed detection circuit end point. When multiple drive modules are used in parallel, this point of each drive module can be connected together. The modules can share a set of the aforementioned speed detection circuits to simplify the circuits for external system cooperation. 556472 The aforementioned unit is a circuit board. The circuit board is provided with a plurality of terminals on at least one edge, and each of the plurality of terminals is respectively connected to an input, output terminal or connection node of each circuit on the circuit board for plugging into an external control. Corresponding connector set in the system; or as a circuit board module, directly plugged or soldered to other circuit boards. With the aforementioned modular design, the drive module and cooling fan can be increased or decreased according to actual needs. Quantity. [Embodiment] As shown in the first figure, it is a schematic diagram of the appearance of a preferred embodiment of the cooling fan driving module of the present invention. The fan driving circuit and other related circuits and components are constructed on a circuit board (100). The circuit board (1 0 0) is provided with a plurality of terminals (1 0 1) to (1 0 8) on at least one edge to form a module unit; wherein each terminal (1 0 1) to ( 1 0 8) and respectively connected to the input, output terminal or connection node of each circuit on the circuit board (100), so as to input a control signal or output a detection signal through the terminals (1 01) to (1 0 8), As for the terminals (101) to (108), the connection interfaces for corresponding plugging into an external control system, or as a circuit board (PCB) module, directly plugging or soldering to other circuit boards to Connect the external control system, cooling fan, and other status detection circuits through the connection interface, so that the external control system drives the cooling fan through the drive module, and the drive module itself and other status detection circuits detect whether the fan is Normal operation, power Temperature and the severity of the overload condition or the power supply system, according to an external control system for adjusting the rotational speed of the cooling fan, and effectively improve the heat dissipation efficiency. 556472 Please refer to the second figure for the circuit structure of the aforementioned drive module on the circuit board (1 〇ο). It includes at least one drive circuit (1 〇), which is controlled by external control. The pulse width modulation circuit (not shown) in the system is controlled, and its output end is connected to at least one group of fans, and the pulse width modulation circuit adjusts the width of the output pulse signal to change the speed of the fan; the drive circuit ( 10) is mainly composed of a switching transistor (1 1) and at least one driving transistor (1 2) (1 3). In this embodiment, the driving transistor (1 2) (1 3) is two ; Among them, the base of the switching transistor (1 1) is connected to a resistor R1, and a fan speed control terminal (FANSPD) is formed at the other end of the resistor R1, and is connected to the terminal (106) for inputting a pulse with a variable pulse width. Wave signal, the emitter is connected to the bases of the two driving transistors (1 2) (1 3), and the two driving transistors (1 2) (1 3) are respectively connected in parallel with the resistors R6 and R12 between the collector and the emitter. And an audit diode ZD1, ZD2, and a fan connection terminal FAN1, FAN2 are formed on the collector, respectively, which Do not connect the terminals (101) (102) on the circuit board (100) for connecting the driven fan; because the collector and emitter of the aforementioned driving transistor (12) (13) are arranged between There is an audit diode ZD1, ZD2, so for the connected DC fan, a DC voltage of 9 ~ 12 volts is given by the audit diodes ZD1, ZD2 before starting, thereby reducing the fan startup. Its current amount. The other functions and effects of this design will be detailed later. In addition, the driving circuit (1 0) is further connected to a rotation speed detection circuit (1 4). The input terminals of the rotation speed detection circuit (1 4) are respectively passed through a reverse diode D1, D2 and the driving circuit (1 0). The two driving transistor 556472 body (1 2) (1 3) collectors are connected to determine whether the fan is stuck. The rotation speed detection circuit (1 4) is composed of a transistor (1 5) and a number of resistors R7 to R10. Among them, a collector of the transistor (1 5) pulls out a fan jam detection terminal FANCLK, and is connected to The terminals (107) on the circuit board (100) are connected for the external control system to detect whether the fan has a LOCK condition. In addition to the aforementioned lines, a node between the drive circuit (1 0) and the speed detection circuit (1 4) is pulled out to connect a drive module in parallel to set the common speed detection circuit end point PARALLEL, which is connected to the circuit board ( 1 0 0), when multiple drive modules are used in parallel, this point of each drive module can be connected together, and the parallel modules can share the same speed detection circuit described above In order to simplify the circuit of the external system. The ground GND1 and GND2 of the driving circuit (10) are connected to terminals (103) (104) on the circuit board (100), respectively, as common ground points. According to the above description, the specific circuit structure of the driving module of the present invention can be seen, and its further working principle is as follows: Please refer to the third figure, which is a partial circuit of the foregoing driving circuit (1 0), and mainly discloses among them A driving transistor (1 2), a set of the driving transistor (1 2), a resistor R6 connected between the emitters, an audit diode ZD1 and a fan F1 connected to the collector thereof. As shown in the waveform diagram on the left, it is assumed that the pulse wave signal is input to the base of the driving transistor (1 2). Because the driving transistor (1 2) has an audit diode (ZD1) between its collector and emitter, When the driving transistor (1 2) is turned off, a DC voltage will be added to the collector, so that the voltage waveform across the fan 10 556472 is shown on the right. Please also refer to the fourth figure, which reveals the state when the driving transistor (1 2) in the third figure is not conducting. The DC voltage source VCC is connected to the ground via the resistor R6 and the ZD1 diode. There is a DC voltage between F1 and the ground terminal GND1. When the driving transistor (1 2) is turned on (as shown in the fifth figure), the DC voltage source VCC is driven to ground through the driving transistor (1 2), so the DC voltage is sent to the fan F1 to start running. A DC voltage already exists, so it can effectively reduce the amount of current when the fan F1 is started, so the stress on the fan bearing during start-up is relatively small, so it can extend its working life, and its operation will be more under normal working conditions. For smooth. Also, each driving transistor (1 2) in the driving circuit (10) is connected and driven with a fan, but multiple sets of fans can be connected and driven at the same time. As shown in the sixth figure, multiple fan drives are disclosed. The module drives multiple sets of cooling fans F1 ~ Fn at the same time. In this implementation mode, the terminal PARALLEL of the setting common speed detection circuit of multiple fan drive modules is connected together, so that the external control system can simply use the fan of one of the modules to block the detection terminal FANCLK, and then In order to detect whether there is a fan lock (LOCK) condition in multiple groups of fans. Since the aforementioned drive module is controlled by an external pulse width modulation circuit, both the pulse width modulation circuit is used to control the speed, and it can further consider other parameters as a reference for adjusting the speed of the fan, as shown in the second figure The temperature detection circuit (20) is mainly used to detect the temperature of the power supply system or power supply. When the temperature of the power supply system or power supply is high, the heat dissipation requirement is increased. 556472 High 'pulse width modulation circuit can be driven through The module increases the fan speed to further enhance the cooling effect. When the system temperature is low, it indicates that the heat dissipation requirement is reduced, and the pulse width modulation circuit reduces the fan speed through the drive module, so that the cooling fan works more efficiently. Another reference factor that controls the speed of the fan is the load of the load. When the power system or power supply is overloaded, the heat dissipation needs should be relatively high. Therefore, the pulse width modulation circuit can increase the fan speed through the drive module. To enhance heat dissipation. When the system is lightly loaded, the heat dissipation requirement is relatively low, so the pulse width modulation circuit reduces the fan speed through the drive module to reduce the power consumption. Therefore, it can be known from the above that the present invention is mainly to modularize the cooling fan drive circuit used in the power supply system or power supply. In the modularized design, the heat dissipation requirements of the power supply system or power supply can be easily expanded. For the industry, it can quickly and easily complete the configuration of the cooling system according to different system specifications. It can be seen that the present invention makes the traditional independent cooling fan drive circuit have a significant improvement in efficiency compared with the traditional method. It has both industrial availability, novelty and progress, and meets the requirements of invention patents, and has filed an application according to law. [Brief description of the drawings] (I) Schematic part The first figure is a schematic diagram of the appearance of a preferred embodiment of the present invention. The first figure is a circuit diagram of a preferred embodiment of the present invention. Stomach BIL: It is a schematic diagram of the local circuit and input / output signals of a preferred embodiment of the present invention. Fig. 4 is a schematic diagram of a partial circuit and its working state of a preferred embodiment of the present invention. (Transistor cut-off) Stomach: Figure is a partial circuit and its working state of a preferred embodiment of the present invention. (Transistor conduction) Figure 6: Schematic diagram of a partial circuit of another preferred embodiment of the present invention. (~) Element representative symbol (10) Driving circuit (11) Switching transistor (1 2) (1 3) Driving transistor (1 4) Signal detection circuit (1 5) Transistor (2 0) Temperature detection Circuit (1 0 〇) circuit board (1 0 1) ~ (1 0 8) terminals
1313