201019057 九、發明說明： 【發明所屬之技術領域】 本發明涉及一種風扇控制裝置及其控制方法。 【先前技術】 風扇散熱技術被廣泛地用於各種電子裝置内以保说 子裝置在正常之溫度範圍内工作。一般地，電子裝置： 設有感測器，使電子裝置可對風扇之轉速作適時調整。 請參見圖1，先前技術中，一種風扇控制方法係 設定若干個模式適時控制風扇之轉速，以滿足不同之‘埶 要求。具體地’若該感應之環境溫度在第一模式對應之;盈 度範圍内，電子裝置控制風扇以第—轉速運轉；若此: 扇轉速不能滿足散熱需求M吏電子裝置内部溫度升高，、導 致該感應之環境溫度升高並落人至第二模式對應之溫度範 圍内，此時需要提高風扇之轉速至第二轉速，且該第二模 式對應之溫度範圍之下限為該第—模式對應之溫度範圍之 上限。 © 惟由於提高風扇轉速後會使該錢之環境溫度有短時 Η田度下If #而會使該感應之環境溫度小於該第二模式 對應之溫度範圍之下限，從而使風扇之轉速又降低至該第 -轉速，此時由於該第-轉速無法从散熱需求，該感應 之環境溫度又很快突破該第—模式對應之溫度範圍之上 限’重新落入第二模式對應之溫度範圍内，風扇之轉速又 要提高至第二轉速，如此經過反復提高轉速—降低轉速— 提高轉速之過程後，直到提高風扇轉速所導致之該感應之 環境溫度下降仍大於該第二模式對應之溫度範圍之下限為 7 201019057 止，風扇方可穩定地保持該第二轉速轉動從而完成提高轉 速之過程。因此先前技術之風扇提高轉速之過程中會出現 •頻繁之轉速切換，給使用者帶來難以接受之雜訊。 【發明内容】 有鑒於此，有必要提供一種控制風扇穩定切換轉速之 風扇控制裝置及其控制方法。 一種用於控制電子裝置内之風扇轉速之風扇控制裝 置，其包括·預設有複數個模式並可在該複數個模式間相 ⑩互切換之處理器，記憶體及感測器，該感測器用於感應該 電子裝置内之環境溫度。該複數個模式包括一第一模式及 一第二模式。該第一模式對應第一溫度範圍，用於控制該 風扇以第一轉速運轉。該第二模式對應第二溫度範圍用 於控制該風扇以大於該第一轉速之第二轉速運轉，該第二 溫度範圍與該第一溫度範圍部分重疊且該第二溫度範圍之 上限大於該第一溫度範圍之上限。該記憶體存儲有一個風 扇控制系統，且該處理器能夠執行該風扇控制系統。該風 ❿扇控制系統包括：獲取模組及判斷模組。該獲取模組用於 獲取該感測器感應之環境溫度。該判斷模組用於判斷該感 應之環境溫度是否在當前模式對應之溫度範圍内。若該感 應之環境溫度不在當前模式對應之溫度範圍内，則進一步 =斷，感應之環境溫度是否大於或等於該當前模式對應之 溫度範圍之上限；若該感應之環境溫度大於或等於該當前 模式對應之溫度範圍之上限，則判斷該感應之環境溫度是 否大於該複數個模式對應之溫度範圍之上限之最大值；若 該感應之環境溫度不大於該複數個模式對應之溫度範圍之 8 201019057 上限之最大值，則該處理器切換模式以提高風扇轉速。 一種用於控制電子裝置内之風扇轉速之風扇控制方 法，包括以下步驟： 提供一風扇控制裝置，所述風扇控制裝置包括：預設 有複數個模式並可在該複數個模式間相互切換之處理器， 記憶體及感測器，該感測器用於感應該電子裝置内之環境 溫度；該複數個模式包括一第一模式及一第二模式，該第 一模式對應之第一溫度範圍，用於控制該風扇以第一轉速 ®運轉；該第二模式對應第二溫度範圍，用於控制該風扇以 大於該第一轉速之第二轉速運轉，該第二溫度範圍與該第 一溫度範圍部分重疊且該第二溫度範圍之上限大於該第一 溫度範圍之上限； 獲取該感測器感應之環境溫度； 判斷該感應之環境溫度是否在當前模式對應之溫度範 圍内，當前模式選自該複數個模式中之其中一個，若該感 應之環境溫度不在當前模式對應之溫度範圍内，則進一步 β判斷=感應之環境溫度是否大於或等於該當前模式對應之 /瓜度範圍之上限，若該感應之環境溫度大於或等於該當前 模式對應之溫度範圍之上限，則判斷該感應之環境溫度是 否大於該複數個模式對應之溫度範圍之上 該感應之環境溫度不大於該複數個模式對應之溫度範圍之 上限之最大值，則切換模式以提高風扇轉速。 相對於先前技術，所述風扇控制裝置及其控制方法籍 由設置與該第-溫度範圍部分重疊之第二溫度範圍，從而 使該風扇在#高轉速造成該感應之環境溫度短時下降後仍 9 201019057 能保持以提高後之轉速轉動，避免風扇轉速因該感應之環 境溫度短時下降而導致轉速降低所帶來之轉速頻繁切換之 問題。 【實施方式】 請一併參見圖2至圖4, 一種用於控制電子裝置10内 之風扇轉速之風扇控制裝置100,其包括：預設有第一模 式130及第二模式132之處理器ι2〇，記憶體14〇及感測 器110。該處理器12〇可控制該第一模式13〇及該第二模 ❹式132之間相互切換。該感測器n〇用於感應該電子裝置 10内之環境溫度。該風扇控制裝置100用於控制風扇200 之轉速。電源300給該電子裝置1〇供電。該第一模式13〇 對應第一溫度範圍為[〇 , tl)，在該第一模式13〇下，即， 當該感應之環境溫度Ts落入到該第一溫度範圍時，該處理 器120控制風扇200以第一轉速運轉。該第二模式132對 應第二溫度範圍[t2，t3)，該第二溫度範圍與該第一溫度範 圍部分重疊，且該第二溫度範圍之上限大於該第一溫度範 ©圍之上限^ ’即t2<tl<t3,其中，t2為該第二溫度範圍之 下限，b為該第二溫度範圍之上限，在該第二模式132下， 即，^該感應之環境溫度Ts落入到該第二溫度範圍時，該 處理器120控制該風扇2〇〇以大於該第一轉速之第二轉速 f轉，該第二温度範圍與該第一溫度範圍部分重疊之重疊 範圍根據該電子裝置1〇之散熱需求而確定。較佳地，該處 理器120還預設-個中斷溫度【卿，該中斷溫度％叫大於 u第模< 130及該第二模式132所對應之溫度範圍之上 限之最大值t3 ’即tst0p > t3。下面簡要說明設定該中斷溫 201019057 度tst()p之目的：該中斷溫度tst()p之設定主要參考該電子裝 置10所能承受之發熱量，為了保護該電子裝置10,當風 扇200以最大轉速運轉仍無法使該電子裝置10有效散熱， ' 從而使該感應之環境溫度Ts大於或等於該中斷溫度tstop 時，該處理器120使該電子裝置10停止工作。 所述記憶體140存儲有一個風扇控制系統150，且所 述處理器120能夠執行該風扇控制系統150，該風扇控制 系統150包括：獲取模組152及判斷模組154。該獲取模 〇 組152用於獲取該感測器110感應之環境溫度Ts。該判斷 模組154用於判斷該感應之環境溫度Ts是否在當前模式對 ~ 應之溫度範圍内；若該感應之環境温度几在該當前模式對 • 應之溫度範圍内，則該處理器120保持當前模式；若該感 應之環境溫度Ts小於該當前模式對應之溫度範圍之下 限，則該處理器120切換模式降低該風扇200之轉速；若 該感應之環境溫度Ts大於該當前模式對應之溫度範圍之 上限，則該判斷模組154進一步判斷該感應之環境溫度Ts G 是否大於該第一模式及第二模式對應之溫度範圍之上限之 最大值；若該感應之環境溫度Ts不大於該第一模式及第二 模式對應之溫度範圍之上限之最大值，則該處理器120切 換模式以提高該風扇200之轉速。若該感應之環境溫度Ts 大於該第一模式及第二模式對應之溫度範圍之上限之最大 值，則該判斷模組154再進一步判斷該感應之環境溫度Ts 是否大於或等於該中斷溫度tst()p，若該感應之環境溫度Ts 大於或等於該中斷溫度tstQp，該處理器120使該電子裝置 10停止工作。若該感應之環境溫度Ts小於該中斷溫度 11 201019057 tst°P ’該處理器120控制該風扇200保持當前轉速。 為了更詳細說明本發明實施方式，設當前模式為第一 ^模式13〇，則此時該風扇200以第一轉速進行運轉，當該 ，，之％境溫度T2ti ’該處理器120切換至第二模式132 提南，風扇200之轉速，該風扇2〇〇之轉速之提高使該感 應，之環境溫度ts會出現短時下降t〇，即Ts，= Ts_ t〇，其中 Ts’為提高轉速後之感應之環境溫度，由於該第二溫度範圍 與第一溫度範圍有部分重疊，故使該提高轉速後之感應之 ®環，溫度Ts’仍㈣在該第二溫度範圍内而沒有小於該第 一溫度範圍之下限，使該風扇200仍然保持第二轉速，而 不會因為該感應之環境溫度下降t〇而出現降低轉速之狀 况，從而保證該風扇穩定切換轉速。 若在第二模式132下，該電子裝置1〇之内部溫度繼續 上升，使該感應之環境溫度Ts>t3，則該判斷模組154進 一步判斷是否Ts2tsU)p，若此時該電子裝置1〇之内部溫度 仍然得不到有效散熱致使該感應之環境溫度則該 ©處理器120使該電子裝置10停止工作，一般地，籍由二 處理器120切斷該電源300來實現；若否，該處理^ 保持該第二模式132。 若在第二模式132下，該電子裝置10之内部溫度得到 有效降低，使該感應之環境溫度Ts<t2，則該處理器12〇 切換至該第一模式130以降低該風扇2〇〇之轉速。 參見圖5’本發明提供一種用於控制電子褒置内之風 扇轉速之風扇控制方法。 步驟S100··提供一風扇控制裝置，所述風扇控制裝置 12 201019057 包括：預設有複數個模式並可在該複數個模式間相互切換 之處理器，記憶體及感測器，該感測器用於感應該電子裝 置内之環境温度；該複數個模式包括一第一模式及一第二 模式’該第-模式對應第-溫度範圍，用於控制該風扇以 第一轉速運轉；該第二模式對應第二溫度範圍，該第二溫 度範圍與該第一溫度範圍部分重疊且該第二溫度範圍:: 限大於該第一溫度範圍之上限，該第二模式用於控制該風 扇以大於該第一轉速之第二轉速運轉；201019057 IX. Description of the Invention: [Technical Field] The present invention relates to a fan control device and a control method therefor. [Prior Art] Fan heat dissipation technology is widely used in various electronic devices to ensure that the device operates in a normal temperature range. Generally, the electronic device: is provided with a sensor, so that the electronic device can adjust the rotation speed of the fan in time. Referring to Figure 1, in the prior art, a fan control method sets a number of modes to control the speed of the fan in time to meet different requirements. Specifically, if the ambient temperature of the sensing corresponds to the first mode; within the range of the profit, the electronic device controls the fan to operate at the first speed; if the fan speed cannot meet the heat dissipation requirement, the internal temperature of the electronic device increases, The ambient temperature of the sensing is increased and falls to a temperature range corresponding to the second mode. At this time, the rotation speed of the fan needs to be increased to the second rotation speed, and the lower limit of the temperature range corresponding to the second mode is the first mode corresponding to the first mode. The upper limit of the temperature range. © However, if the ambient temperature of the money is short after the fan speed is increased, the If # will cause the ambient temperature of the induction to be lower than the lower limit of the temperature range corresponding to the second mode, thereby reducing the rotation speed of the fan. Up to the first speed, at this time, because the first speed cannot be removed from the heat dissipation requirement, the induced ambient temperature quickly breaks through the upper limit of the temperature range corresponding to the first mode and falls back into the temperature range corresponding to the second mode. The rotation speed of the fan is further increased to the second rotation speed. After the process of repeatedly increasing the rotation speed-reducing the rotation speed-increasing the rotation speed, the ambient temperature drop caused by the increase of the fan rotation speed is still greater than the temperature range corresponding to the second mode. The lower limit is 7 201019057, and the fan can stably maintain the second rotation speed to complete the process of increasing the rotation speed. Therefore, the prior art fan may have a high speed switching process during the process of increasing the rotational speed, which brings unacceptable noise to the user. SUMMARY OF THE INVENTION In view of the above, it is necessary to provide a fan control device that controls a stable switching speed of a fan and a control method thereof. A fan control device for controlling a fan speed in an electronic device, comprising: a processor, a memory and a sensor, which are pre-configured with a plurality of modes and can be mutually switched between the plurality of modes, the sensing The device is used to sense the ambient temperature within the electronic device. The plurality of modes includes a first mode and a second mode. The first mode corresponds to a first temperature range for controlling the fan to operate at a first rotational speed. The second mode corresponds to the second temperature range for controlling the fan to operate at a second rotational speed greater than the first rotational speed, the second temperature range partially overlapping the first temperature range and the upper limit of the second temperature range is greater than the first The upper limit of a temperature range. The memory stores a fan control system and the processor is capable of executing the fan control system. The wind fan control system comprises: an acquisition module and a determination module. The acquisition module is configured to obtain an ambient temperature sensed by the sensor. The determining module is configured to determine whether the ambient temperature of the sensing is within a temperature range corresponding to the current mode. If the ambient temperature of the sensing is not within the temperature range corresponding to the current mode, further = off, whether the sensed ambient temperature is greater than or equal to an upper limit of the temperature range corresponding to the current mode; if the sensed ambient temperature is greater than or equal to the current mode Corresponding to the upper limit of the temperature range, determining whether the induced ambient temperature is greater than the maximum value of the upper limit of the temperature range corresponding to the plurality of modes; if the induced ambient temperature is not greater than the temperature range corresponding to the plurality of modes, the upper limit of 201019057 The maximum value is then the processor switches modes to increase fan speed. A fan control method for controlling a fan speed in an electronic device, comprising the steps of: providing a fan control device, the fan control device comprising: a process of pre-setting a plurality of modes and mutually switching between the plurality of modes And a sensor for sensing an ambient temperature in the electronic device; the plurality of modes includes a first mode and a second mode, the first mode corresponding to the first temperature range, Controlling the fan to operate at a first speed®; the second mode corresponds to a second temperature range for controlling the fan to operate at a second speed greater than the first speed, the second temperature range and the first temperature range portion Overlap and an upper limit of the second temperature range is greater than an upper limit of the first temperature range; obtaining an ambient temperature sensed by the sensor; determining whether the sensed ambient temperature is within a temperature range corresponding to the current mode, the current mode is selected from the plurality One of the modes, if the ambient temperature of the induction is not within the temperature range corresponding to the current mode, further β judgment = Whether the ambient temperature is greater than or equal to the upper limit of the range corresponding to the current mode, and if the induced ambient temperature is greater than or equal to the upper limit of the temperature range corresponding to the current mode, determining whether the induced ambient temperature is greater than the complex number If the ambient temperature of the sensed temperature range is not greater than the maximum value of the upper limit of the temperature range corresponding to the plurality of modes, the mode is switched to increase the fan speed. In contrast to the prior art, the fan control device and the control method thereof are configured to set a second temperature range partially overlapping the first temperature range, so that the fan is still lowered after the high temperature causes the induced ambient temperature to decrease for a short time. 9 201019057 It can keep rotating at an increased speed, avoiding the problem that the fan speed is frequently switched due to the short-time drop of the induced ambient temperature. [Embodiment] Please refer to FIG. 2 to FIG. 4 together, a fan control device 100 for controlling the fan speed in the electronic device 10, which includes: a processor ι2 pre-configured with the first mode 130 and the second mode 132 〇, memory 14〇 and sensor 110. The processor 12 can control the first mode 13 〇 and the second mode 132 to switch between each other. The sensor n is used to sense an ambient temperature within the electronic device 10. The fan control device 100 is used to control the rotational speed of the fan 200. The power source 300 supplies power to the electronic device 1 . The first mode 13 〇 corresponds to a first temperature range of [〇, tl), and in the first mode 13 ,, that is, when the induced ambient temperature Ts falls within the first temperature range, the processor 120 The control fan 200 is operated at a first rotational speed. The second mode 132 corresponds to a second temperature range [t2, t3), the second temperature range partially overlapping the first temperature range, and the upper limit of the second temperature range is greater than an upper limit of the first temperature range. That is, t2 < tl < t3, where t2 is the lower limit of the second temperature range, b is the upper limit of the second temperature range, and in the second mode 132, that is, the induced ambient temperature Ts falls into the In the second temperature range, the processor 120 controls the fan 2 to rotate at a second speed f greater than the first speed, and the overlapping range of the second temperature range partially overlapping the first temperature range is according to the electronic device 1 Determined by the heat dissipation requirements. Preferably, the processor 120 further presets an interrupt temperature, which is greater than the maximum value t3 of the upper limit of the temperature range corresponding to the uth mode < 130 and the second mode 132, that is, tst0p > t3. The following is a brief description of the purpose of setting the interrupt temperature 201019057 degrees tst()p: the setting of the interruption temperature tst()p mainly refers to the amount of heat that the electronic device 10 can withstand. To protect the electronic device 10, when the fan 200 is maximized The operation of the rotational speed still fails to effectively dissipate the electronic device 10, so that the processor 120 stops the electronic device 10 from operating when the induced ambient temperature Ts is greater than or equal to the interrupted temperature tstop. The memory 140 stores a fan control system 150, and the processor 120 can execute the fan control system 150. The fan control system 150 includes an acquisition module 152 and a determination module 154. The acquisition module group 152 is configured to acquire an ambient temperature Ts sensed by the sensor 110. The determining module 154 is configured to determine whether the sensed ambient temperature Ts is within a temperature range of the current mode pair; if the sensed ambient temperature is within a temperature range of the current mode pair, the processor 120 Maintaining the current mode; if the sensed ambient temperature Ts is less than the lower limit of the temperature range corresponding to the current mode, the processor 120 switching mode reduces the rotational speed of the fan 200; if the induced ambient temperature Ts is greater than the temperature corresponding to the current mode The upper limit of the range, the determining module 154 further determines whether the induced ambient temperature Ts G is greater than a maximum value of an upper limit of the temperature range corresponding to the first mode and the second mode; if the induced ambient temperature Ts is not greater than the first The maximum value of the upper limit of the temperature range corresponding to the mode and the second mode is that the processor 120 switches the mode to increase the rotational speed of the fan 200. If the sensing ambient temperature Ts is greater than the maximum value of the upper limit of the temperature range corresponding to the first mode and the second mode, the determining module 154 further determines whether the induced ambient temperature Ts is greater than or equal to the interrupt temperature tst ( And, if the induced ambient temperature Ts is greater than or equal to the interruption temperature tstQp, the processor 120 stops the electronic device 10. If the sensed ambient temperature Ts is less than the interrupted temperature, the processor 120 controls the fan 200 to maintain the current rotational speed. In order to explain the embodiment of the present invention in more detail, if the current mode is the first mode 13 〇, then the fan 200 is operated at the first rotational speed, and when the temperature is reached, the processor 120 switches to the first The second mode 132, the speed of the fan 200, the increase of the speed of the fan 2使 causes the induction, the ambient temperature ts will appear short-term d〇, ie Ts, = Ts_ t〇, where Ts' is the increased speed After the ambient temperature of the sensing, the second temperature range partially overlaps with the first temperature range, so that the sensing ring after the increasing speed, the temperature Ts' is still (4) in the second temperature range and not less than the The lower limit of the first temperature range causes the fan 200 to maintain the second rotation speed without a situation of lowering the rotation speed due to the induced ambient temperature drop t〇, thereby ensuring that the fan stably switches the rotation speed. If the internal temperature of the electronic device 1 continues to rise in the second mode 132, and the induced ambient temperature Ts > t3, the determining module 154 further determines whether Ts2tsU)p, if the electronic device is at this time The internal temperature is still not effectively dissipated, so that the ambient temperature of the sensing causes the electronic processor 10 to stop working. Generally, the second processor 120 cuts off the power supply 300; if not, the Processing ^ maintains the second mode 132. If the internal temperature of the electronic device 10 is effectively reduced in the second mode 132, and the induced ambient temperature Ts < t2, the processor 12 switches to the first mode 130 to reduce the fan 2 Rotating speed. Referring to Figure 5', the present invention provides a fan control method for controlling the speed of a fan within an electronic unit. Step S100··providing a fan control device, the fan control device 12 201019057 includes: a processor, a memory and a sensor, which are preset with a plurality of modes and can switch between the plurality of modes, the sensor is used for the sensor Sensing an ambient temperature in the electronic device; the plurality of modes includes a first mode and a second mode, the first mode corresponding to a first temperature range, configured to control the fan to operate at a first rotational speed; the second mode Corresponding to the second temperature range, the second temperature range partially overlapping the first temperature range and the second temperature range: the limit is greater than an upper limit of the first temperature range, the second mode is for controlling the fan to be greater than the first Running at a second speed of one speed;
步驟S200 獲取孩厫測器感應之環境溫度； 步驟S300:判斷該感應之環境溫度是否在當前模式對 f之溫度範圍内’當前模式選自預設之複數個模式中之盆 :一個，若該感應之環境溫心在#前模式對應之溫度範 =’則執打步驟剛：判斷該感應之環境溫度是否大於 該當前模式對應之溫度範圍之上限；若該感應之環 大於或等於該當前模式對應之溫度範圍之上限，則 ==测：判斷該感應之環境溫度是否大於該複數個 複數個模式對應之溫度範圍之上 則執仃步驟S501:切換模式以提高風扇轉速。 圍之？=之環境溫度大於該複數個模式對應之溫度範 於或大於預設之中斷溫度二== 數=式所對應之溫度範圍之上限之最大值·若是，則 、、二=Γ:使該電子裝置停止工作;若該感應之環境 ，皿度小於該中斷溫度，則執行步驟〇:保持該當前模式。 13 201019057 若該感應之環境溫度小於該當前模式對應之溫度範圍 -之下限’則執行步驟切換模式以降低風扇轉速。 , 乡該感應之環境溫度在當前模式對應之溫度範圍内， 則執行步驟S301 ··保持該當前模式。 相對於先前技術，所述風扇控制裝置及其控制方法籍 由設置與該第-溫度範圍部分重叠之第二温度範圍，從而 使該風扇在提馬轉速造成該感應之環境溫度短時下降後仍 ❹ 能保持以提高後之轉速轉動，避免風扇轉速因該感應之環 境溫度短時下降而導致轉速降低所帶來之轉速頻繁切換之 問題。 综上所述，本發明符合發明專利要件，爰依法提出專 利申4。惟，以上所述者僅為本發明之較佳實施方式，本 發月之範圍並不以上述實施方式為限，舉凡熟悉本案技藝 之人士援依本發明之精神所作之等效修飾或變化，皆應涵 蓋於以下申請專利範圍内。 Ο 【圖式簡單說明】 圖1為先前技術中風扇模式之設置示意圖。 圖2為本發明提供之風扇控制裝置之硬體圖。 圖3為圖2中之風扇控制裝置之模式之設置示意圖。 圖4為圖2中之風扇控制裝置之風扇控制系統之功能 模組圖。 圖5為本發明提供之風扇控制方法之流程圖。 【主要元件符號說明】 子装置 10 風扇控制裝置 100 201019057 感測器 110 處理器 120 第一模式 130 第二模式 132 記憶體 140 風扇控制系統 150 風扇 200 電源 300 獲取模塊 152 判斷模塊 154 15Step S200: obtaining the ambient temperature sensed by the child detector; Step S300: determining whether the sensed ambient temperature is within a temperature range of the current mode pair f. The current mode is selected from the preset plurality of modes: one, if The ambient temperature of the sensing is in the temperature mode of the #前模式=' then the step of the step is: determining whether the ambient temperature of the sensing is greater than the upper limit of the temperature range corresponding to the current mode; if the ring of the sensing is greater than or equal to the current mode The upper limit of the corresponding temperature range is == measured: determining whether the induced ambient temperature is greater than the temperature range corresponding to the plurality of modes, then performing step S501: switching the mode to increase the fan speed. Surrounded by? The ambient temperature is greater than the temperature range corresponding to the plurality of modes, or greater than the preset interruption temperature. The number of the upper limit of the temperature range corresponding to the formula ============================ The device stops working; if the sensing environment is less than the interruption temperature, then step 〇 is performed: maintaining the current mode. 13 201019057 If the ambient temperature of the induction is less than the lower temperature range of the current mode - then perform the step switching mode to reduce the fan speed. If the ambient temperature of the sense is within the temperature range corresponding to the current mode, step S301 is performed. · The current mode is maintained. In contrast to the prior art, the fan control device and the control method thereof are configured to set a second temperature range partially overlapping the first temperature range, so that the fan is still lowered after the Tuma rotation speed causes the induced ambient temperature to decrease for a short time. ❹ It can keep rotating at the increased speed, avoiding the problem that the fan speed is frequently switched due to the short-time drop of the induced ambient temperature. In summary, the present invention complies with the requirements of the invention patent, and the patent application is filed according to law. However, the above description is only a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiments, and those skilled in the art will be able to make equivalent modifications or variations in accordance with the spirit of the present invention. All should be covered by the following patent application. Ο [Simple description of the drawing] Fig. 1 is a schematic diagram showing the setting of the fan mode in the prior art. 2 is a hardware diagram of a fan control device provided by the present invention. 3 is a schematic view showing the arrangement of the mode of the fan control device of FIG. 2. 4 is a functional block diagram of a fan control system of the fan control device of FIG. 2. FIG. 5 is a flowchart of a fan control method provided by the present invention. [Main component symbol description] Sub-device 10 Fan control device 100 201019057 Sensor 110 Processor 120 First mode 130 Second mode 132 Memory 140 Fan control system 150 Fan 200 Power supply 300 Acquisition module 152 Judgment module 154 15