200838088 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種電源保護電路，特別是關於 一種電源保護電路可適用於一車用充電器。 【先前技術】 人們外出辦公時或外出旅遊所攜帶如PDA或 是手機等此類的電子產品常因為配置電池的電量有 限，而讓使用者無法繼續使用此類的產品，於是業 者遂開發出一種車充型充電器來解決上述之電量不 足的問題。 然而消費者對於車充型充電器的要求，不僅功 能要多，樣式要吸引人，安全性更是重要。且基於 安全考量’車充型充電器在使用的充電電路上都設 有保護機制，以防止車充型充電器因過負載、過電 流或短路之情形發生。 而習知車充型充電器所使用的電源保護機制大 多採用至少一種以上的電子元件來作為一保護電 路。如在現有車充型充電器之電源電路上採用突波 抑制二極體（TVS Diode)、突波吸收器（varistor) 或熱敏電阻（thermistor)等元件。以突波抑制二極 體之電性而言’突波抑制二極體為粉制電壓抑制 器，當電壓加在其兩端時，突波抑制二極體將經由 電阻之變化而提供一低阻抗之路徑，一旦電壓移 走，突波抑制二極體將回復到其高維持電壓之阻 5 200838088 抗。所以，採用突波抑制二極體則有快速反應時間 及適合低電壓之應用等優點。或選用熱敏電阻作為 一保護電路時，當車充型充電器進行充電，此時， 車充熱敏型充電器的電壓與電蕊溫度會不斷地升 南’因此可利用熱敏電阻檢測電子設備中的過熱現 象，可防止電路吸收過大電流’以停止充電及放電 動作。 雖然前述所提及的電子元件有諸多優點，但不 f 幸的事，車充型充電器之電源電路在進行充電時， 若驅動源存有一異常能量之電壓信號而超過前述所 突波抑制二極體或熱敏電阻所能承載的電氣規格 (如時間過長或電流過大），則會使此類型電子元件 的壽命降低。 【發明内容】 因此本發明的目的在於提供一種電源保護電 C 路，適用於一車用充電器，在此電路包含如金氧半 導體電晶體之一切換開關、如雙載子接面電晶體之 一偵測元件及一保護電路，其中此保護電路係由多 個電阻及所相應串聯及並聯之稽納二極體所組成。 於一實施例中，一直流電源對車用充電器進行充電 的期間（during charging)，偵測元件如果偵測到的 電壓高於一臨界電壓時，會令切換開關呈關閉（of 〇 狀態，藉此使電源保護電路與車用充電器所形成的 200838088 、充包迴路變成斷路，可避免異常的電壓或電流造 成車用充包☆損害。而且，在本發明之電源保護電 路所使用的稽納二極體係可根據所搭配之材料規格 而任意設定保護之啟動電壓值以符合使用設備裝置 之所需保護電壓之方便性且可設定變換。 择據上述之目的，本發明揭露一種電源保護電 路，適用於車用充電器，此車用充電器至少包含一 驅動源’且驅動源係輸出一電源之電壓至電源保護電 路此電路包含··一切換開關、一偵測元件及一保護 電路。切換開關，用以導通（〇n)或關閉所接收之電 =^私壓。偵測元件係連接於切換開關，用於债測 電壓是否高於一臨界電壓而決定是否導通或關閉切 換開關。保護電路係連接於切換開關及偵測元件， 用於提供切換開關及偵測元件之電壓限制保護。當 車用充電器充電的過程期間，偵測元件如果偵測到 的包壓鬲於一臨界電壓時，會關閉切換開關，以令 切換開關呈一關閉狀態，藉此使電源保護電路與車 用充電器所形成的一充電迴路形成斷路。 【實施方式】 以下詳細地討論目前較佳的實施例。然而應被 理解的是，本發明提供許多可適用的發明觀念，而 這些觀念能被體現於很寬廣多樣的特定具體背景 中。所討論的特定具體的實施例僅是說明使用本發 200838088 明的^定結f，而且不會限制本發明的範圍。 ^明苓考第1圖所示，此圖為本發明之電源保護 %路之方塊示意圖，且此電源保護電路1適用於一 車^充電器。其中此車用充電器至少包含一具一輸 泰鳊111及輸出端112之驅動源11。而電源保護 f路1包含：一切換開關12、一偵測器13及一保護 =路14(pr〇tecti〇n circuit)。於本實施例中，驅 2源11係採用一直流電源(DC)，以便提供直流功率 II入至電源保護電路丨。而切換開關12係接收由驅 _源11之輪入端Hi所輸入之一電壓，用以導通（〇n) 或關閉（off)所接收之電源之電壓。偵測器13係連 接於=換開關12，且於偵測前述電壓是否高於一臨 界私壓，用以控制切換開關12導通或關閉。保護電 路14係連接於切換開關12及偵測器13，用以提供 切择開關12及偵測器13之電壓限制保護，可避免 /、苇的笔壓或電流而造成電源保護電路1損害。 請參閱第2圖所示，此圖為本發明之電 電路之電路示意圖。由圖中可知，此電 1更包含一電源線15及一接地線16。而前述保 路14係由一第一二極體141與—第一電阻142所組 成，且第一二極體141之一陰極端14n(cath〇de) 連接至電源線15及第一二極體141之一陽極端 1412 (anode )係連接至接地線16。而第一電阻142 係設置在電源線15上，且第一電阻142之二第一端 200838088 1421與第一二極體141之陰極端1411連接至電源 線15之一端點。於第1圖中所提及的偵測器13與 切換開關12,在本圖中係分別使用雙載子接面電晶 體 13 (bipolar junction transistor)及金氧半導 體電晶體 12 (Metal-Oxide-Semiconductor Field-Effect Transistor，MOSFET)，在本實施例 中雙載子接面電晶體13亦為PNP電晶體或NPN電晶 體兩者一，以本實施例，以PNP電晶體13為代表例， 以及金氧半導體電晶體12亦是η-型的MOSFET，簡 稱NM0S。且在此電源保護電路1之電路尚包含有一 具一第三端1431及一第四端1432之第二電阻 143、一具一第五端1441及一第六端1442之第三電 阻144、一具一第七端1451及一第八端1452之第 四電阻145、一具一第九端1461及一第十端1462 之第五電阻146、一具一第一端1471及一第二端 1472之電容147以及用於設定前述臨界電壓之一第 二二極體148，以下為本電路之各電子元件之較詳 細說明。在第二電阻143、第三電阻144、第四電阻 145及第五電阻146之各端點中，第二電阻143之 第三端1431連接於雙載子接面電晶體13之基極端 132及第二電阻143之第四端1432連接第三電阻 144之第六端1442。而第三電阻144之第五端1441 與第一電阻142之第二端1422連結於電源線15之 一端點。第四電阻145之第七端1451及第八端1452 200838088 係分別連接於第一二極體141之陽極端1412及接地 線16。第五電阻146之第九端1461及第十端1462 係分別連接於第三電阻144之第六端1442及第二二 極體148之一陰極端1481及第二二極體148之一陽 極端1482係連接至接地線16。電容147之第一端 1471及一第二端1472係分別連接於雙載子接面電 晶體13之射極端131與基極端132。而金氧半導體 電晶體12之源極端121 (source)、閘極端122(gate) 及汲極端123(drain)係分別連接雙載子接面電晶 體13之集極端133、第一電阻142之第二端1422 及驅動源11之輸出端112。其中前述第一二極體141 及第二二極體148分別為一第一稽納二極體141及 一第二稽納二極體 148 (zener diode)。 請參閱第3圖所示，此圖係根據第2圖之電源 保護電路於充電過程之示意圖。於車用充電器充電 時，直流電源之電流（以下簡稱直流電流I)流向係 流經電源保護電路1而至驅動源11之輸出端112。 且在車用充電器充電前，先由第二稽納二極體148 設定一臨界電壓，並由雙載子接面電晶體13偵測所 輸入的電壓是否高於臨界電壓而決定是否導通或關 閉切換開關12，如習知技術所知悉，雙載子接面電 晶體13可由基極端132的電流控制其集極端133 與射極端131間的電流導通程度。而在正常情況下 (也就是直流電源提供的直流功率其電壓值不超過 200838088 前述設定臨界電壓時），所輸出電壓不會超過第一稽 納二極體141的崩饋電壓（breakdown voltage)，故 第一稽納二極體141會在逆偏但不導通的工作區。 請注意，為能將金氧半導體電晶體12導通，閘極端 122與源極端121必須要傳遞足夠的電流，因第一 稽納二極體141處在不導通的工作區’所以，流經 雙載子接面電晶體13之射極端131之電流h有較 大電流，使得雙載子接面電晶體13之集極端133 之電流Ic也有較大電流，換言之，此種射極端131 之電流Ie與集極端133之電流Ic關係係滿足金氧半 導體電晶體12導通之閘極端122與源極端121傳遞 足夠的電流的要求。此時金氧半導體電晶體12之閘 極端122亦透過電源線15、第一電阻142 —直電連 到的直流電源之輸入端111，而金氧半導體電晶體 12之源極端121亦透過雙載子接面電晶體13之集 極端133、第四電阻145 —直電連到接地線16，使 得金氧半導體電晶體12之閘極端122與源極端121 間的電壓大於金氧半導體電晶體12之啟始電壓而 導通。 由上述討論可知，在車用電充器於正常充電情 況下，因為本發明之電源保護電路1係以雙載子接 面電晶體13控制金氧半導體電晶體12，進而控制 整個電源保護電路1的功率傳輸功能。而如習知技 術所熟知，金氧半導體電晶體12為電壓控制型元件 11 200838088 (voltage-controlled)，其閘極端122的阻抗非常 大，尤其在直流操作下，其閘極端12 2漏電流幾乎 等於零。所以本發明之電源保護電路1，於正常充 電情況下，係提供足夠的電流至金氧半導體電晶體 12之閘極端122與源極端121，以致導通金氧半導 體電晶體12。請注意，本發明之電源保護電路1在 正常充電情況下，因第一稽納二極體141不導通， 使得第四電阻145沒有電流流過，減少電源保護電 路1的功率消耗。 再者，本發明之電源保護電路1可防止錯誤的 過電壓（即超過由第二稽納二極體148設定的臨界 電壓）。此直流電源之直流功率其輪入電壓大於臨界 電壓，會使第一稽納二極體141逆偏超過崩饋電 壓，而使第一稽納二極體141導通。第一稽納二極 體141導通後，直流電流I會在第一電阻142之第 一端1421分流，換言之，會有部分電流會流經第一 稽納二極體141及第四電阻145。而為能將金氧半 導體電晶體12呈關閉狀態，只須將閘極端122與源 極端121間的電壓移去即可。此外，流經雙載子接 面電晶體13之射極端131之電流Ie有較小電流， 使得雙載子接面電晶體13之集極端133之電流Ic 也有較小電流，此種射極端131之電流Ie電流與集 極端133之電流Ic的關係，遂使得金氧半導體電晶 體12之閘極端122與源極端121無法要傳遞足夠的 12 200838088 電流，進而無法導通金氧半導體電晶體12，因而金 氧半導體電晶體12呈關閉關閉狀態。 相較於習知技術，本發明所提供的電源保護電 路至少具有一保護電路及一切換開關，可保護車用 充電器避免受到異常的電壓或電流的損害。其中當 一反向直流電壓或是一超過一臨界電壓之正向直流 電壓經由電源插座之正輸入端及接地端輸入時，此 電源保護電路會關閉金氧半導體電晶體，藉此使電 源保護電路與車用充電器所形成的一充電迴路變成 斷路。而當一低於臨界電壓之正向直流電壓經由電 源插座之正輸入端及接地端輸入時，雙載子接面電 晶體所提供的電流則會導通金氧半導體電晶體之閘 極端與源極端，並進而使以使正向直流電壓得已經 由雙載子接面電晶體而輸入至車用充電器之内部電 路。 請注意，當車用充電器過度充電時，在第2圖 中之電源保護電路之第一電阻142亦能提供過電流 之保護機制，及第一稽納二極體141亦能提供雙載 子接面電晶體13之射極端131與集極端133 (V^) 的電壓限制保護與金氧半導體電晶體12之閘極端 122與源極端121 (U的電壓限制保護。再者，因 PNP雙載子接面電晶體13為了能使電流更大，通常 在基極端132做得較薄，故電源保護電路亦在雙載 子接面電晶體13之基極端132連接一第二電阻143 13 200838088 一端U3卜使得第二電阻143亦能保護pNp雙 ΡΝΡ ίΠί曰體13之基極端132與射極端⑶或 避免:擊穿電晶體之基極端132與集極端133 雖然本發明已以較佳實施例揭露如上，然其並 II以限定本發明’任何熟習此技藝者，在不脫離 ★明之精神和範圍内，當可作各種之更動與潤200838088 IX. Description of the Invention: [Technical Field] The present invention relates to a power supply protection circuit, and more particularly to a power supply protection circuit that can be applied to a vehicle charger. [Prior Art] People who go out to work or go out to travel with electronic products such as PDAs or mobile phones often have difficulty in using such products because of the limited power of the configured batteries, so the industry has developed a kind of Car charger type charger to solve the above problem of insufficient power. However, consumers' requirements for car chargers are not only more important, but also attractive in style. Safety is even more important. And based on safety considerations, the car charger type charger has a protection mechanism on the charging circuit to prevent the car charger type charger from being overloaded, overcurrent or short circuited. The power protection mechanism used by conventional car chargers mostly uses at least one electronic component as a protection circuit. For example, a surge suppression diode (TVS Diode), a surge absorber (therstor) or a thermistor (thermistor) is used in the power supply circuit of the existing car charger. In terms of the electrical properties of the surge suppressing diode, the surge suppressor diode is a powder voltage suppressor. When a voltage is applied across the two ends, the surge suppression diode will provide a low resistance through the change in resistance. The impedance path, once the voltage is removed, the surge suppression diode will return to its high sustain voltage resistance. Therefore, the use of surge suppression diodes has the advantages of fast response time and suitable for low voltage applications. Or when the thermistor is used as a protection circuit, when the car charger is charged, at this time, the voltage of the car charger and the temperature of the battery will continue to rise. Therefore, the thermistor can be used to detect the electron. Overheating in the device prevents the circuit from absorbing excessive current' to stop charging and discharging. Although the electronic components mentioned above have many advantages, it is not fortunate that when the power supply circuit of the charger type charger is charged, if the driving source stores an abnormal energy voltage signal, it exceeds the aforementioned surge suppression two. Electrical specifications (such as excessive time or excessive current) that can be carried by a polar body or thermistor can reduce the life of this type of electronic component. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a power protection circuit C, which is suitable for a vehicle charger, and the circuit includes a switch such as a MOS transistor, such as a bipolar junction transistor. A detecting component and a protection circuit, wherein the protection circuit is composed of a plurality of resistors and corresponding series and parallel senser diodes. In an embodiment, when the DC power source charges the vehicle charger, the detecting component detects that the voltage is higher than a threshold voltage, so that the switch is turned off (of 〇 state, Thereby, the 200838088 and the charging circuit formed by the power protection circuit and the vehicle charger are turned off, and the abnormal voltage or current can be prevented from causing damage to the vehicle charging package. Moreover, the power supply protection circuit of the present invention is used. The nano-polar system can arbitrarily set the protection starting voltage value according to the material specifications to match the convenience of using the required protection voltage of the device device and can be set and changed. According to the above purpose, the present invention discloses a power protection circuit. It is suitable for a vehicle charger. The vehicle charger includes at least one driving source' and the driving source outputs a voltage of the power source to the power protection circuit. The circuit includes a switching switch, a detecting component and a protection circuit. A switch for turning on (〇n) or turning off the received power = ^ private voltage. The detecting component is connected to the switch for debt testing Whether the voltage is higher than a threshold voltage determines whether to turn on or off the switch. The protection circuit is connected to the switch and the detecting component, and is used for providing voltage limit protection of the switch and the detecting component. During the detection, if the detected component is clamped to a threshold voltage, the switch is turned off to cause the switch to be in a closed state, thereby causing a charging circuit formed by the power protection circuit and the vehicle charger. [Embodiment] The presently preferred embodiments are discussed in detail below, but it should be understood that the present invention provides many applicable inventive concepts which can be embodied in a wide variety of specific specific contexts. The specific embodiment discussed is merely illustrative of the use of the present invention, and does not limit the scope of the invention. As shown in Figure 1, the figure is a power protection of the present invention. A block diagram of the % road, and the power protection circuit 1 is suitable for a car charger. The car charger includes at least one transmission baht 111 and The drive source 11 of the output terminal 112. The power supply protection path 1 includes: a switch 12, a detector 13 and a protection circuit 14 . In this embodiment, the source 2 The 11 Series uses a DC power supply (DC) to provide DC power II into the power protection circuit. The switch 12 receives a voltage input from the wheel input terminal Hi of the drive source 11 for conduction (〇n Or off (off) the voltage of the received power source. The detector 13 is connected to the = change switch 12, and detects whether the voltage is higher than a critical private voltage to control the switch 12 to be turned on or off. The circuit 14 is connected to the switch 12 and the detector 13 for providing voltage limiting protection of the switch 12 and the detector 13. The power protection circuit 1 can be damaged by avoiding the pen pressure or current. Please refer to FIG. 2, which is a circuit diagram of the electrical circuit of the present invention. As can be seen from the figure, the power 1 further includes a power line 15 and a ground line 16. The protection circuit 14 is composed of a first diode 141 and a first resistor 142, and a cathode end 14n (cath〇de) of the first diode 141 is connected to the power line 15 and the first diode. One of the anode ends 1412 (anode) of the body 141 is connected to the ground line 16. The first resistor 142 is disposed on the power line 15, and the first end of the first resistor 142, 200838088 1421, and the cathode end 1411 of the first diode 141 are connected to one end of the power line 15. The detector 13 and the changeover switch 12 mentioned in FIG. 1 respectively use a bipolar junction transistor and a metal oxide semiconductor transistor 12 (Metal-Oxide- in the figure). In the present embodiment, the bipolar junction transistor 13 is also a PNP transistor or an NPN transistor. In this embodiment, the PNP transistor 13 is taken as a representative example, and The MOS transistor 12 is also an η-type MOSFET, abbreviated as NM0S. The circuit of the power protection circuit 1 further includes a second resistor 143 having a third terminal 1431 and a fourth terminal 1432, a third resistor 144 having a fifth terminal 1441 and a sixth terminal 1442, and a third resistor 144. a fourth resistor 145 having a seventh end 1451 and an eighth end 1452, a fifth resistor 146 having a ninth end 1461 and a tenth end 1462, a first end 1471 and a second end 1472 The capacitor 147 and the second diode 148 for setting the threshold voltage are described in more detail below for each electronic component of the circuit. In each of the end points of the second resistor 143, the third resistor 144, the fourth resistor 145, and the fifth resistor 146, the third end 1431 of the second resistor 143 is coupled to the base terminal 132 of the bipolar junction transistor 13 and The fourth end 1432 of the second resistor 143 is coupled to the sixth end 1442 of the third resistor 144. The fifth end 1441 of the third resistor 144 and the second end 1422 of the first resistor 142 are coupled to one end of the power line 15. The seventh end 1451 and the eighth end 1452 200838088 of the fourth resistor 145 are respectively connected to the anode terminal 1412 of the first diode 141 and the ground line 16. The ninth end 1461 and the tenth end 1462 of the fifth resistor 146 are respectively connected to the sixth end 1442 of the third resistor 144 and one of the cathode end 1481 of the second diode 148 and the anode end 1482 of the second diode 148. Connect to ground wire 16. The first end 1471 and the second end 1472 of the capacitor 147 are respectively connected to the emitter end 131 and the base end 132 of the bipolar junction transistor 13. The source terminal 121 (gate), the gate terminal 122 (gate) and the drain terminal 123 (drain) of the MOS transistor 12 are respectively connected to the collector terminal 133 of the bipolar junction transistor 13 and the first resistor 142. The second end 1422 and the output end 112 of the driving source 11. The first diode 141 and the second diode 148 are a first gate diode 141 and a second Zener diode 148, respectively. Please refer to Figure 3, which is a schematic diagram of the power protection circuit according to Figure 2 during the charging process. When the vehicle charger is charged, the current of the DC power source (hereinafter referred to as DC current I) flows through the power source protection circuit 1 to the output terminal 112 of the drive source 11. Before the charging of the vehicle charger, a threshold voltage is set by the second sigma diode 148, and the bipolar junction transistor 13 detects whether the input voltage is higher than the threshold voltage to determine whether to conduct or The diverter switch 12 is turned off. As is known in the art, the bi-carrier junction transistor 13 can control the degree of current conduction between the collector terminal 133 and the emitter terminal 131 from the current of the base terminal 132. Under normal conditions (that is, when the DC power supplied by the DC power source does not exceed the threshold voltage set forth in 200838088), the output voltage does not exceed the breakdown voltage of the first sigma diode 141. Therefore, the first sigma diode 141 will be in the reverse but not conductive work area. Please note that in order to turn on the MOS transistor 12, the gate terminal 122 and the source terminal 121 must transmit sufficient current because the first gate diode 141 is in a non-conducting working area. The current h of the emitter terminal 131 of the carrier junction transistor 13 has a large current, so that the current Ic of the collector terminal 133 of the bipolar junction transistor 13 also has a large current, in other words, the current Ie of the emitter terminal 131. The current Ic relationship with the collector terminal 133 satisfies the requirement that the gate terminal 122 of the MOS transistor 12 is turned on and the source terminal 121 delivers sufficient current. At this time, the gate terminal 122 of the MOS transistor 12 is also transmitted through the power line 15, the first resistor 142, the input terminal 111 of the DC power source directly connected to the DC power source, and the source terminal 121 of the MOS transistor 12 is also transmitted through the dual load. The collector terminal 133 and the fourth resistor 145 of the sub-junction transistor 13 are directly connected to the ground line 16 such that the voltage between the gate terminal 122 and the source terminal 121 of the MOS transistor 12 is greater than that of the MOS transistor 12. Start voltage and turn on. It can be seen from the above discussion that in the case of normal charging of the vehicle, since the power protection circuit 1 of the present invention controls the MOS transistor 12 with the bipolar junction transistor 13, the entire power protection circuit 1 is controlled. Power transfer function. As is well known in the art, the MOS transistor 12 is a voltage-controlled component 11 200838088 (voltage-controlled), and its gate terminal 122 has a very high impedance, especially under DC operation, its gate terminal 12 2 leakage current is almost Equal to zero. Therefore, the power protection circuit 1 of the present invention supplies sufficient current to the gate terminal 122 and the source terminal 121 of the MOS transistor 12 under normal charging conditions to turn on the MOS transistor 12. Please note that in the case of normal charging, the power protection circuit 1 of the present invention reduces the power consumption of the power protection circuit 1 because the first resistor 141 is not turned on, so that no current flows through the fourth resistor 145. Furthermore, the power supply protection circuit 1 of the present invention can prevent erroneous overvoltages (i.e., exceed the threshold voltage set by the second arrester diode 148). The DC power of the DC power source has a wheel-in voltage greater than a threshold voltage, which causes the first-signal diode 141 to reversely exceed the collapse voltage, and the first-signal diode 141 is turned on. After the first gated diode 141 is turned on, the direct current I is shunted at the first end 1421 of the first resistor 142. In other words, a portion of the current flows through the first arrester diode 141 and the fourth resistor 145. In order to turn off the MOS transistor 12, it is only necessary to remove the voltage between the gate terminal 122 and the source terminal 121. In addition, the current Ie flowing through the emitter terminal 131 of the bipolar junction transistor 13 has a small current, so that the current Ic of the collector terminal 133 of the bipolar junction transistor 13 also has a small current, and the emitter terminal 131 The relationship between the current Ie current and the current Ic of the collector terminal 133 causes the gate terminal 122 and the source terminal 121 of the MOS transistor 12 to fail to pass sufficient current of 12, 2008, 380, 88, thereby failing to conduct the MOS transistor 12, thereby The MOS transistor 12 is turned off. Compared with the prior art, the power protection circuit provided by the present invention has at least one protection circuit and a switch to protect the vehicle charger from abnormal voltage or current. When a reverse DC voltage or a forward DC voltage exceeding a threshold voltage is input through the positive input terminal and the ground terminal of the power socket, the power protection circuit turns off the MOS transistor, thereby making the power protection circuit A charging circuit formed with the vehicle charger becomes an open circuit. When a forward DC voltage lower than the threshold voltage is input through the positive input terminal and the ground terminal of the power socket, the current supplied by the bipolar junction transistor turns on the gate terminal and the source terminal of the MOS transistor. And further, so that the forward DC voltage is input to the internal circuit of the vehicle charger by the dual carrier junction transistor. Please note that when the vehicle charger is overcharged, the first resistor 142 of the power protection circuit in FIG. 2 can also provide an overcurrent protection mechanism, and the first sigma diode 141 can also provide a dual carrier. The voltage limit protection of the emitter terminal 131 and the collector terminal 133 (V^) of the junction transistor 13 and the gate terminal 122 and the source terminal 121 of the MOS transistor 12 (U voltage limiting protection. Furthermore, due to the PNP dual load The sub-junction transistor 13 is usually made thinner at the base end 132 in order to make the current larger, so the power supply protection circuit is also connected to the second resistor 143 13 at the base end 132 of the bi-carrier junction transistor 13 . U3 enables the second resistor 143 to also protect the base terminal 132 and the emitter terminal (3) of the pNp 或 Π 或 13 or avoid: breakdown of the base electrode 132 and collector terminal 133 of the transistor. Although the invention has been disclosed in the preferred embodiment As above, and II, in order to define the present invention, anyone skilled in the art can make various changes and changes without departing from the spirit and scope of the invention.
，因此本發明之保護範圍當視後附之申請專利範 圍所界定者為準。 【圖式簡單說明】 每為讓本發明之上述和其他目的、特徵、優點鱼 二施例能更明顯易懂，所附圖式之詳細說明如下··、 f1圖係為本發明之電源保護電路之一方塊示意圖； 第2圖係為本發明之電源保護電路之一電路示音、 圖；以及 心 第3圖係為一直流電源應用於第2圖之電路示意圖。 【主要元件符號說明】 1 ·電源保護電路； 11:驅動源， 111:輸入端； 112:輸出端； 12:切換開關、金氧半導體電晶體； 14 200838088 1 2 1 :源極端； 122:閘極端； 123:汲極端； 13:偵測器、雙載子接面電晶體； 131:射極端； 13 2 :基極端； 133 :集極端； 14:保護電路； 141:第一二極體、第一稽納二極體； 1411:陰極端； 1412:陽極端； 142:第一電阻； 1421:第一端； 1422:第二端； 143:第二電阻； 1431:第三端； 1432:第四端； 144:第三電阻； 1441:第五端； 1442:第六端； 145:第四電阻； 1451:第七端； 1452:第八端； 146:第五電阻； 15 200838088 1461:第九端； 1462:第十端； 147:電容； 1471:第一端； 1472:第二端； 148:第二二極體、第二稽納二極體 1481:陰極端； 14 8 2 :陽極端； 15:電源線； 16:接地線； I:直流電流；Therefore, the scope of protection of the present invention is defined by the scope of the appended patent application. BRIEF DESCRIPTION OF THE DRAWINGS Each of the above and other objects, features and advantages of the present invention can be more clearly understood. The detailed description of the drawings is as follows: · f1 is the power protection of the present invention. A block diagram of a circuit; Fig. 2 is a circuit diagram, diagram of a power protection circuit of the present invention; and FIG. 3 is a schematic diagram of a circuit in which a DC power source is applied to FIG. [Main component symbol description] 1 · Power supply protection circuit; 11: Drive source, 111: Input terminal; 112: Output terminal; 12: Diverter switch, MOS transistor; 14 200838088 1 2 1 : Source terminal; 122: Gate Extreme; 123: 汲 extreme; 13: detector, bi-carrier junction transistor; 131: emitter extreme; 13 2: base extreme; 133: set extreme; 14: protection circuit; 141: first diode, First genus diode; 1411: cathode end; 1412: anode end; 142: first resistor; 1421: first end; 1422: second end; 143: second resistor; 1431: third end; Fourth end; 144: third resistor; 1441: fifth end; 1442: sixth end; 145: fourth resistor; 1451: seventh end; 1452: eighth end; 146: fifth resistor; 15 200838088 1461: Ninth end; 1462: Tenth end; 147: Capacitance; 1471: First end; 1472: Second end; 148: Second diode, Second Jen diode 2481: Cathode end; 14 8 2 : Anode terminal; 15: power line; 16: ground line; I: DC current;
Ie:電流；以及 I c:電流。 \ 16Ie: current; and I c: current. \ 16