M391791 099年07月28日梭正替換頁 五、新型說明： 【新型所屬之技術領域】 [0001] 本新型主要涉及一種過熱保護電路及使用其的電子設備 〇 【先前技術】 [0002] 隨著電子設備功能的曰益豐富，所需的電路模組或晶片 的數量增加，因此消耗的功率也相應增加。同時，為適 應電子設備小型化、便攜化的趨勢，需要將該等電路模 組或晶片置於儘量小的空間。因此，當該等電路模組或 晶片工作異常時，容易造成電子設備内部溫度過高，對 電子設備造成不可逆轉的過熱損害。 【新型内容】 [0003] 有鑑於此，需提供一種過熱保護電路，為電子設備提供 過熱保護。 ' V ： -* -V - [0004] 同時，還需提供一種使用該過熱保護電路的電子設備。 [0005] 本新型實施方式中的過熱保護電路，用於為電子設備提 供過熱保護，包括溫度感測電路、磁滯比較器及開關電 路。其中，溫度感測電路用於感測該電子設備的内部溫 度並輸出相應的電壓訊號。磁滯比較器通過比較該電壓 訊號與過熱電壓及重啟電壓，從而將該電子設備的内部 溫度與過熱溫度及重啟溫度進行比較，並當該電子設備 的内部溫度高於過熱溫度時輸出斷電訊號，當該電子設 備的内部溫度低於重啟溫度時輸出上電訊號。開關電路 用於根據該上電訊號或斷電訊號相應導通或截止該電子 表單编號A0101 第3頁/共17頁 099年07月28日 設備的電源訊號供應。 本新型實施方式巾的電子設備，包括卫作電路電源電 路及過熱簡祕。其巾，電讀出電源訊號 為工作電路供電。祕保護電路包括溫度感測電路、磁 滞比較器及開關電路。其中，溫度感測電路用於感測該 電子設備的内部溫度並輸出相應的電壓訊號。磁滯比較 器通過比較該電壓訊號與過熱電壓及重啟轉，從而將 該電子設備的内冑溫度與過熱溫度及重啟溫度進行比較 ，並當該電子設備的内部溫度高於過熱溫度時輪出斷電 訊號，當該電子設備的内部溫度低於重啟溫度時輸出上 電訊號。開關電路用於根據擎上電訊赫斷零訊號相應 導通或截止該電子設備的電漆訊號供應。 本新型提出的過熱保護電路及使用其的電子設備，可根 據電子設備内部溫度變化相應關閉或重啟工作電路，為 電子設備提供過熱保護從而避免過熱損害。 -... .- . 【實施方式】 圖1為本新型提出的電子設備10的一種實施方式的示意圖 。如圖1所示，電子設備1〇包括電源電路U〇、工作電路 120及過熱保護電路13〇。其中，電源電路11〇用於輸出 電源訊號為工作電路12〇供電。工作電路12〇為電子設備 10中實現特疋功能的電路模組或晶片，如顯示電路、存 儲電路或處理器等。過熱保護電路130連接於電源電路 110與工作電路120之間，用於為電子設備1〇提供過熱保 護。當電子設備10内部溫度高於過熱溫度時，過熱保護 第4頁/共17頁 電路130截止電子設備10的電源訊號供應。當電子設備10 A0101 I 099年07月28日修正替换 冷卻至内部溫度低於重啟溫度時，過熱保護電路⑽重新 導通電子設備1G的電源訊號供應。在本實施方式中，過 熱溫度根據電子設備10正常運行的上限溫度設定，例如 上限溫度為9GT：時，過熱溫度可設定細t。重啟溫度 根據電子設備10的環境溫度設定，例如環境溫度為25<t 時’重啟溫度可設定為45t：。顯然，過熱溫度高於重啟溫 度。 [0009] 在本實施方式中，過熱保護電路13〇包括溫度感測電路 131、磁滯比較器132及開關電路133。溫度感測電路131 用於感測電子設偫1〇的内部溫度，並輸出相應的電壓訊 號表示電子設備10的内部溫磁滯比較器132用於比較 該電壓訊號與過熱電壓或重_電^擊(，從吊將電子設備1〇 的内部溫度與過熱溫度或重啟溫度進行比較。其中，過 熱電壓為磁滯比較器132的下限閾值，用於表示電子設備 10的過熱溫度6重啟電壓為磁滯.比較器132的上限閾值， ί W:. 用於表示電子設備10的重啟溫友。當該電子設備的内部 溫度高於過熱溫度時，磁幕比較5器132輸出斷電訊號。當 ... ' 該電子設備的内部溫度低於重啟溫度時，磁滯比較器132 輸出上電訊號。 [0010] 開關電路133用於根據磁滯比較器132輸出的斷電訊號或 上電訊號相應截止或導通電子設備1〇電源訊號的供應。 在本實施方式中’開關電路133連接於電子設備10的電源 電路110與工作電路120之間，並根據磁滯比較器132輸 出的斷電訊號斷開電源電路110與工作電路120之間的連 接。電源電路110與工作電路120之間的連接中斷後，工 表單編號Α0101 第5頁/共17頁 M391791 093年07月28日修正替換頁 作電路120停止工作，電子設備1〇開始冷卻，使得内部溫 度降低從而避免過熱損害。當電子設備1〇冷卻至内部溫 度低於重啟溫度時，磁滯比較器j 3 2輸出上電訊號。開關 電路133根據磁滯比較器132輸出的上電訊號重新導通電 源電路110與工作電路120間的連接，工作電路12〇重新 開機。 [0011] 圖2為本新型提出的電子設備中過熱保護電路13〇的一 種實施方式的具體電路圖。如圖2所示，溫度感測電路 131包括第一分壓電路。其中，第一分壓電路連接於第一 參考電壓VI與地之間，包括依次_聯的電阻以及熱敏電 阻R2。電阻R1及熱敏電阻R2_公共節點作為溫度感測電 路131的輸出端。溫度感測棄路131的輪出電壓u用於表 示電子設備10的内部溫度》在本實施方式中，熱敏電阻 R2為負溫度係數（Negative Temperature Coefficient， NTC) 型電阻 ’其電阻值將隨溫度增加而減小， 故溫度感測電路131的輸出電壓U丨隨溫度增加而減小◊在 其他實施方式中，熱敏電阻R2也可為正溫度係數（positive Temperature Coefficient, PTC) 型電阻， 電阻值將隨溫度增加而增大，其與電阻r 1依次串聯於第 一參考電壓VI與地之間。因此，溫度感測電路131的輸出 電壓U丨同樣隨溫度增加而減小。 [0012] 磁滯比較器132包括運算放大器A1、穩壓二極體D1及第二 分壓電路。其中，第二分壓電路一端與第二參考電壓V2 相連’另一端與穩壓二極體D1陰極相連。第二分壓電路 包括依次串聯的電阻R3及R4。電阻R3及R4的公共節點作 表單編號A0101 第6頁/共17頁 M391.791 099年07月28日修正替换頁 為第二分壓電路的分壓節點。運算放大器A1反相輸入端 與第一分壓電路中電阻R1及熱敏電阻R2的公共節點相連 ，同相輸入端與第二分壓電路中電阻R3及電阻R4的公共 節點相連，輸出端經電阻R5輸出上電訊號或斷電訊號。 穩壓二極體D1的陽極接地，陰極經電阻R5與運算放大器 A1輸出端相連。在本實施方式中，穩壓二極體D1的穩定 電壓為U。其中，U大於電源電路110輸出的電源訊號的 L· L· 電壓。 [0013] 同時參閱圖3，其為本新型提出的過熱保護電路130中磁 滯比較器132特性的示意圖。其中，Upi&Up2分別為磁滯 比較器132的上限閾值及下_閾斧。上值Upi及下限 閾值uD()可由以下公式得出。11' ,' P 2 :广 ' , [0014] Upl=U2xR3/ (R3 + R4) +U_xR4/ (R3 + R4)M391791 July 28th, 2008, the replacement of the shuttle page, the new description: [New technical field] [0001] The present invention mainly relates to an overheat protection circuit and an electronic device using the same [Prior Art] [0002] The power of electronic devices is so rich that the number of circuit modules or chips required increases, so the power consumed increases accordingly. At the same time, in order to adapt to the trend of miniaturization and portability of electronic devices, it is necessary to place such circuit modules or wafers in as small a space as possible. Therefore, when the circuit modules or the chips work abnormally, the internal temperature of the electronic device is too high, causing irreversible overheating damage to the electronic device. [New content] [0003] In view of this, it is necessary to provide an overheat protection circuit to provide overheat protection for electronic equipment. ' V : -* -V - [0004] At the same time, it is necessary to provide an electronic device using the overheat protection circuit. The overheat protection circuit of the present embodiment is for providing overheat protection for an electronic device, including a temperature sensing circuit, a hysteresis comparator, and a switching circuit. The temperature sensing circuit is configured to sense an internal temperature of the electronic device and output a corresponding voltage signal. The hysteresis comparator compares the voltage signal with the superheat voltage and the restart voltage to compare the internal temperature of the electronic device with the superheat temperature and the restart temperature, and outputs a power-off signal when the internal temperature of the electronic device is higher than the superheat temperature. When the internal temperature of the electronic device is lower than the restart temperature, the power-on signal is output. The switch circuit is configured to turn on or off the electronic form number A0101 according to the power-on signal or the power-off signal. A0101 Page 3 of 17 The power signal supply of the device is July 28, 2008. The electronic device of the novel embodiment includes a power circuit of the circadian circuit and a superheating function. Its towel, the electrical read power signal supplies power to the working circuit. The secret protection circuit includes a temperature sensing circuit, a hysteresis comparator, and a switching circuit. The temperature sensing circuit is configured to sense an internal temperature of the electronic device and output a corresponding voltage signal. The hysteresis comparator compares the voltage signal with the superheat voltage and restarts, thereby comparing the internal temperature of the electronic device with the superheat temperature and the restart temperature, and when the internal temperature of the electronic device is higher than the superheat temperature, the wheel is broken. The electric signal outputs an electric signal when the internal temperature of the electronic device is lower than the restart temperature. The switch circuit is configured to turn on or off the electrocoat signal supply of the electronic device according to the on-off telecommunications signal. The overheat protection circuit and the electronic device using the same according to the present invention can shut down or restart the working circuit according to the internal temperature change of the electronic device to provide overheat protection for the electronic device to avoid overheating damage. [Embodiment] FIG. 1 is a schematic diagram of an embodiment of an electronic device 10 proposed in the present invention. As shown in FIG. 1, the electronic device 1A includes a power supply circuit U, a working circuit 120, and an overheat protection circuit 13A. The power circuit 11 is used for outputting a power signal to supply power to the working circuit 12 . The working circuit 12 is a circuit module or a wafer, such as a display circuit, a storage circuit or a processor, which implements a special function in the electronic device 10. The overheat protection circuit 130 is connected between the power supply circuit 110 and the working circuit 120 for providing overheat protection for the electronic device 1A. When the internal temperature of the electronic device 10 is higher than the overheating temperature, the overheat protection is turned off. The circuit 130 turns off the power supply of the electronic device 10. When the electronic device 10 A0101 I corrects the replacement on July 28, 2008, and the internal temperature is lower than the restart temperature, the overheat protection circuit (10) re-energizes the power supply of the electronic device 1G. In the present embodiment, the overheating temperature is set according to the upper limit temperature of the normal operation of the electronic device 10. For example, when the upper limit temperature is 9GT:, the superheat temperature can be set to a fine t. Restart temperature According to the ambient temperature setting of the electronic device 10, for example, when the ambient temperature is 25 < t, the restart temperature can be set to 45t:. Obviously, the overheating temperature is higher than the restart temperature. In the present embodiment, the overheat protection circuit 13A includes a temperature sensing circuit 131, a hysteresis comparator 132, and a switching circuit 133. The temperature sensing circuit 131 is configured to sense an internal temperature of the electronic device and output a corresponding voltage signal to indicate that the internal temperature hysteresis comparator 132 of the electronic device 10 compares the voltage signal with the superheat voltage or the weight of the electric device. The internal temperature of the electronic device 1 is compared with the superheat temperature or the restart temperature. The superheat voltage is the lower limit threshold of the hysteresis comparator 132, and is used to indicate that the electronic device 10 is overheated and the restart voltage is magnetic. The upper threshold of the comparator 132, ί W: is used to indicate the restarting temperature of the electronic device 10. When the internal temperature of the electronic device is higher than the superheat temperature, the magnetic screen comparison device 132 outputs a power-off signal. When the internal temperature of the electronic device is lower than the restart temperature, the hysteresis comparator 132 outputs an electric signal. [0010] The switch circuit 133 is configured to be turned off according to the power-off signal or the power-on signal output by the hysteresis comparator 132. Or turning on the supply of the power supply signal of the electronic device 1. In the present embodiment, the 'switching circuit 133 is connected between the power supply circuit 110 of the electronic device 10 and the working circuit 120, and is input according to the hysteresis comparator 132. The power-off signal disconnects the connection between the power supply circuit 110 and the working circuit 120. After the connection between the power supply circuit 110 and the working circuit 120 is interrupted, the work form number is Α0101, page 5 of 17 M391791, July 28, 093 The correction replacement page circuit 120 stops working, and the electronic device 1 starts to cool, so that the internal temperature is lowered to avoid overheating damage. When the electronic device 1 is cooled to an internal temperature lower than the restart temperature, the hysteresis comparator j 3 2 outputs the telecommunication. The switch circuit 133 re-energizes the connection between the power supply circuit 110 and the working circuit 120 according to the power-on signal outputted by the hysteresis comparator 132, and the working circuit 12 is turned back on. [0011] FIG. 2 is a superheat in the electronic device proposed by the present invention. A specific circuit diagram of an embodiment of the protection circuit 13A. As shown in Fig. 2, the temperature sensing circuit 131 includes a first voltage dividing circuit, wherein the first voltage dividing circuit is connected between the first reference voltage VI and the ground. The resistor includes a resistor and a thermistor R2. The resistor R1 and the thermistor R2_ are connected to the output of the temperature sensing circuit 131. The temperature sensing abandonment of the abandonment 131 u is used to indicate the internal temperature of the electronic device 10. In the present embodiment, the thermistor R2 is a negative temperature coefficient (NTC) type resistor, and its resistance value will decrease as the temperature increases, so the temperature sensing is performed. The output voltage U丨 of the circuit 131 decreases as the temperature increases. In other embodiments, the thermistor R2 may also be a positive temperature coefficient (PTC) type resistor, and the resistance value will increase as the temperature increases. It is connected in series with the resistor r 1 between the first reference voltage VI and ground. Therefore, the output voltage U丨 of the temperature sensing circuit 131 also decreases as the temperature increases. [0012] The hysteresis comparator 132 includes an operational amplifier A1, a voltage stabilizing diode D1, and a second voltage dividing circuit. Wherein, one end of the second voltage dividing circuit is connected to the second reference voltage V2, and the other end is connected to the cathode of the voltage stabilizing diode D1. The second voltage dividing circuit includes resistors R3 and R4 connected in series. Common node of resistors R3 and R4 Form No. A0101 Page 6 of 17 M391.791 Revised replacement page on July 28, 099 is the voltage dividing node of the second voltage divider circuit. The inverting input terminal of the operational amplifier A1 is connected to the common node of the resistor R1 and the thermistor R2 in the first voltage dividing circuit, and the non-inverting input terminal is connected to the common node of the resistor R3 and the resistor R4 in the second voltage dividing circuit, and the output end The power signal or power-off signal is output via the resistor R5. The anode of the voltage stabilizing diode D1 is grounded, and the cathode is connected to the output terminal of the operational amplifier A1 via a resistor R5. In the present embodiment, the stable voltage of the voltage stabilizing diode D1 is U. Where U is greater than the L·L· voltage of the power signal output by the power circuit 110. Referring to FIG. 3, it is a schematic diagram showing the characteristics of the hysteresis comparator 132 in the overheat protection circuit 130 of the present invention. Among them, Upi&Up2 is the upper limit threshold and the lower_threshold axe of the hysteresis comparator 132, respectively. Upper value Upi and lower limit The threshold uD() can be derived from the following formula. 11' , ' P 2 : wide ' , [0014] Upl=U2xR3/ (R3 + R4) +U_xR4/ (R3 + R4)
r 1 Lr 1 L
[0015] Up2 = U2xR3/ (R3 + R4) . « [0016] 其中，U2表示第二參考電壓V2的電壓，R3及R4分別表示 電阻R3及R4的電阻值。在本實施方式中，磁滞比較器132 的上限閾值υρι及下限閾值up2分別對應於該過熱電壓及重 啟電壓。上限閾值υρι及下限閾值up2間的電壓差為磁滯比 較器132的滯回電壓。 [0017] 根據磁滯比較器132的特性，當運算放大器A1的反相輸入 端電壓\大於上限閾值11151時，磁滯比較器132輸出電壓 U〇為0伏。當運算放大器A1的反相輸入端電壓U/、於下限 閾值Up2時，磁滯比較器132輸出電壓為Uz。 [0018] 在本實施方式中，當電子設備10内部溫度高於過熱溫度 表單編號A0101 第7頁/共17頁 099年07月28日梭正替換頁 時/m度感測電路131的輸出電Μ u丨小於下限閾值u 。 此時，運异放大器Ai的反相輸入端電壓、小於下限閾值 Up2，磁滯比較器j32輸出電壓、為1^，即斷電訊號。當 電子設備ίο内部溫度低於重啟溫度時，溫度感測電路131 的輸出電壓U!大於上限閾值此時，運算放大器“的 反相輸入端電壓1^大於上限閾值Up〗，磁滯比較器132輸 出電壓U〇為〇伏，即上電訊號。由於磁滯比較器132的滯 回特性，上限閾值UP1及下限閾值Up2之間具有電壓差，因 此重啟溫度及過熱溫度之具有溫度差，這樣電子設備10 - 可以充分冷卻後再重新啟動，從而避免過熱保護時電子 Φ 設備10頻繁關閉及重啟。 [0019]在其他實施方式中，通過調整第二分壓電路中電阻尺3及 R4的電阻值，即可改變下限閾值，從而設定電子設備 10需關閉時的過熱溫度。同時，通過選擇穩壓二極體〇1 的穩定電壓Uz，即可改變上限閾值，從而設定電子設 備10重新開機時的重啟溫度。 圃關電路I33包括金屬氧化氣半導體場效應電晶體（Met_ 書 al Oxide Semiconductor Field Effect Tran- ' sistor，M0SFET)Q1»M0SFET Q1 的源極用於接收電 源電路110輸出的電源訊號’汲極用於輸出電源訊號至工 作電路120，閘極用於接收溫度感測電路131輸出的上電 訊號或斷電訊號，從而相應控制電源電路11〇及工作電路 120之間連接的導通或截止。在本實施方式中，M〇SFET Q1為P通道型。 [0021]在本實施方式中，當電子設備1〇内部溫度正常時，即内 第8頁/共17頁 表單編號A0101 1^99 年 日接頁][0015] Up2 = U2xR3/(R3 + R4) . [0016] wherein U2 represents the voltage of the second reference voltage V2, and R3 and R4 represent the resistance values of the resistors R3 and R4, respectively. In the present embodiment, the upper limit threshold υρι and the lower limit threshold up2 of the hysteresis comparator 132 correspond to the superheat voltage and the restart voltage, respectively. The voltage difference between the upper threshold υρι and the lower threshold threshold up2 is the hysteresis voltage of the hysteresis comparator 132. [0017] According to the characteristics of the hysteresis comparator 132, when the inverting input terminal voltage \ of the operational amplifier A1 is greater than the upper limit threshold 11151, the hysteresis comparator 132 outputs a voltage U 〇 of 0 volts. When the inverting input terminal voltage U/ of the operational amplifier A1 is at the lower limit threshold Up2, the hysteresis comparator 132 outputs a voltage of Uz. [0018] In the present embodiment, when the internal temperature of the electronic device 10 is higher than the overheating temperature form number A0101, page 7 of 17 pages, and the page is replacing the page, the output of the m-degree sensing circuit 131 is output. Μ u丨 is less than the lower threshold u. At this time, the voltage of the inverting input terminal of the operational amplifier Ai is lower than the lower limit threshold Up2, and the output voltage of the hysteresis comparator j32 is 1^, that is, the power-off signal. When the internal temperature of the electronic device ίο is lower than the restart temperature, the output voltage U! of the temperature sensing circuit 131 is greater than the upper limit threshold. At this time, the inverting input terminal voltage 1^ of the operational amplifier is greater than the upper limit threshold Up, and the hysteresis comparator 132 The output voltage U〇 is a sag, that is, a power-on signal. Due to the hysteresis characteristic of the hysteresis comparator 132, there is a voltage difference between the upper threshold UP1 and the lower threshold Up2, so the temperature difference between the restart temperature and the overheat temperature is such that the electron Device 10 - can be fully cooled and then restarted to avoid frequent shutdown and restart of electronic Φ device 10 during overheat protection. [0019] In other embodiments, by adjusting the resistance of resistors 3 and R4 in the second voltage divider circuit The lower limit threshold can be changed to set the overheat temperature when the electronic device 10 needs to be turned off. At the same time, by selecting the stable voltage Uz of the voltage regulator diode ,1, the upper limit threshold can be changed, thereby setting the electronic device 10 to be restarted. The restart temperature of the circuit I33 includes a metal oxide gas semiconductor field effect transistor (Met_ book al Oxide Semiconductor Field Effect Tran- ' sistor The source of the Q1»M0SFET Q1 is used to receive the power signal output from the power circuit 110. The drain is used to output the power signal to the working circuit 120, and the gate is used to receive the power-on signal or the output of the temperature sensing circuit 131. The electrical signal is correspondingly controlled to turn on or off the connection between the power supply circuit 11A and the working circuit 120. In the present embodiment, the M〇SFET Q1 is of the P channel type. [0021] In the present embodiment, when the electronic device 1 〇When the internal temperature is normal, ie, page 8/total 17 pages, form number A0101 1^99, date of the year]
部溫度低於過熱溫度時，溫度感測電路1 31的輸出電壓U 大於U ’即運算放大器A1反相輸入端電壓1|大於^ 。 I P2 根據磁滯比較器132的特性，其輸出電壓U〇為〇伏，即上 電訊號。相應地，開關電路133中MOSFET Q1的閘極與源 極間的電壓差大於導通電壓，故MOSFET Q1導通《開關 電路133導通電源電路11〇及工作電路120間的連接，工 作電路120工作。 [0022] 當電子設備10内部溫度升高時，熱敏電阻R2電阻值降低 ’故溫度感測電路1 31的輸出電壓υ丨相應降低。當電子設 備10内部溫度高於過熱溫度時，溫度感測電路131的輸出 電壓U〗小於UP2，運算放大器A1反相备入端電壓u小於When the temperature of the portion is lower than the temperature of the superheat, the output voltage U of the temperature sensing circuit 1 31 is greater than U ′, that is, the voltage of the inverting input terminal of the operational amplifier A1 is greater than ^. I P2 according to the characteristics of the hysteresis comparator 132, its output voltage U 〇 is 〇, that is, the power-on signal. Correspondingly, the voltage difference between the gate and the source of the MOSFET Q1 in the switch circuit 133 is greater than the turn-on voltage, so that the MOSFET Q1 turns on the connection between the switching circuit 133 and the power supply circuit 11 and the working circuit 120, and the working circuit 120 operates. [0022] When the internal temperature of the electronic device 10 rises, the resistance value of the thermistor R2 decreases, so that the output voltage 温度 of the temperature sensing circuit 1 31 is correspondingly lowered. When the internal temperature of the electronic device 10 is higher than the superheat temperature, the output voltage U of the temperature sensing circuit 131 is smaller than UP2, and the voltage of the inverting terminal of the operational amplifier A1 is less than
,I, I
Up2。根據磁滯比較器132的特性，其’輪出電jfu為U，Up2. According to the characteristics of the hysteresis comparator 132, its 'round-output jfu is U,
〇 Z 即斷電訊號》相應地，開關電路133中MOSFET Q1的閘極 與源極間的電壓差小於導通電壓，故MOSFET Q1截止。 開關電路13 3截止電源電路11 〇及工作電路12〇間的連接 ，工作電路120停止工作，電子設備1〇開始冷卻。 [0023] 隨著電子設備10的冷卻，其内部溫度降低，熱敏電阻R2 電阻值相應增加，故溫度感測電路131的輸出電壓\相應 增加。當電子設備10充分冷卻後，其内部溫度低於重啟 溫度，溫度感測電路131的輸出電壓大於Up〗，即運算 放大器A1反相輸入端電壓11丨大於υρι。根據磁滯比較器 132的特性，其輸出電壓u〇為〇伏，即上電訊號。相應地 ’開關電路133中MOSFET Q1的閘極與源極間的電壓差大 於導通電壓，故MOSFET Q1導通◊開關電路133導通電源 電路110及工作電路120間的連接，工作電路12〇工作。 表單编號A0101 第9頁/共17頁 M391791 __ 099年07月28日核正替换頁 [0024] 本新型提出的過熱保護電路及使用其的電子設備，可根 據電子設備内部溫度變化相應關閉或重啟工作電路，為 電子設備提供過熱保護從而避免過熱損害。 [0025] 綜上所述，本新型符合新型專利要件，爰依法提出專利 申請。惟，以上所述者僅為本新型之較佳實施例，舉凡 熟悉本案技藝之人士，在援依本案新型精神所作之等效 修飾或變化，皆應包含於以下之申請專利範圍内。 【圖式簡單說明】〇 Z is the power-off signal. Accordingly, the voltage difference between the gate and the source of the MOSFET Q1 in the switch circuit 133 is smaller than the turn-on voltage, so the MOSFET Q1 is turned off. The switch circuit 13 3 cuts off the connection between the power supply circuit 11 and the working circuit 12, the working circuit 120 stops operating, and the electronic device 1 starts cooling. [0023] As the electronic device 10 cools, its internal temperature decreases, and the resistance value of the thermistor R2 increases accordingly, so the output voltage of the temperature sensing circuit 131 increases accordingly. When the electronic device 10 is sufficiently cooled, its internal temperature is lower than the restart temperature, and the output voltage of the temperature sensing circuit 131 is greater than Up, that is, the voltage 11丨 of the inverting input terminal of the operational amplifier A1 is greater than υρι. According to the characteristics of the hysteresis comparator 132, its output voltage u 〇 is 〇, that is, the power-on signal. Accordingly, the voltage difference between the gate and the source of the MOSFET Q1 in the switching circuit 133 is larger than the on-voltage, so that the MOSFET Q1 is turned on, the switching circuit 133 is turned on to connect the power supply circuit 110 and the working circuit 120, and the operating circuit 12 is operated. Form No. A0101 Page 9 of 17 M391791 __ July 28, 2008, the replacement of the page [0024] The overheat protection circuit and the electronic device using the same can be turned off according to the internal temperature change of the electronic device or Restart the working circuit to provide overheat protection for the electronic equipment to avoid overheating damage. [0025] In summary, the new type meets the requirements of the new patent, and the patent application is filed according to law. However, the above-mentioned ones are only preferred embodiments of the present invention, and those skilled in the art will be able to include the equivalent modifications or variations in the novel spirit of the present invention. [Simple description of the map]
[0026] 圖1描述了本新型提出的電子設備的一種實施方式； [0027] 圖2描述了本新型提出的過熱保護電路的一種實施方式的 具體電路圖；及 [0028] 圖3描述了本新型提出的過熱保護電路中磁滯比較器的特 性0 【主要元件符號說明】 [0029] 電子設備 10 [0030] /- · 電源電路 110 [0031] 工作電路 120 [0032] 過熱保護電路 130 [0033] 溫度感測電路 131 [0034] 磁滯比較器 132 [0035] 開關電路 133 [0036] 金屬氧化物半導體場效應電晶體 Q1 表單編號A0101 第10頁/共17頁 M391791 099年07月28日修正替换頁 [0037] 運算放大器 A1 [0038] 穩壓二極體 D1 [0039] 電阻 Rl、R3 、R4、R5 [0040] 熱敏電阻 R2 [0041] 參考電壓 VI > V2 表單编號AOIOl 第II頁/共17頁1 illustrates an embodiment of an electronic device proposed by the present invention; [0027] FIG. 2 depicts a specific circuit diagram of an embodiment of the overheat protection circuit proposed by the present invention; and [0028] FIG. 3 depicts the present invention Characteristic 0 of hysteresis comparator in the proposed overheat protection circuit [Description of main component symbols] [0030] Electronic device 10 [0030] /- Power supply circuit 110 [0031] Working circuit 120 [0032] Overheat protection circuit 130 [0033] Temperature sensing circuit 131 [0034] Hysteresis comparator 132 [0035] Metal oxide semiconductor field effect transistor Q1 Form No. A0101 Page 10 of 17 M391791 Correction replacement Page [0037] Operational Amplifier A1 [0038] Regulator Diode D1 [0039] Resistor Rl, R3, R4, R5 [0040] Thermistor R2 [0041] Reference Voltage VI > V2 Form Number AOIOl Page II / Total 17 pages