200840168 九、發明說明： 【發明所屬之技術領域】 本發明係與電源供應裝置有關，特別是指一種電源供 應輸出之電路保護裝置。 5【先前技術】 一般電子、通訊等檢測設備或控制設備等，大多廣泛 以直流開關電源作為電源供應裝置，其中更以複雜的積體 電路兀件作為控制直流電源輸出的開關電路，而為考量元 件有限定之耐壓或耐熱能力，以保護開關電源自身和負載 10的安全，電源供應裝置中多設有過熱、過電壓或過電流等 保濩包路，如第一圖所示為習用防止開關電源過電壓輸入 的一保護電路1，係以一基納二極體ZD1並聯於負載元件 RL，依據基納二極體ZD1的操作特 於電路系統令的電壓上限，以避免因電路不A而發生 ϊ b流開關電源過電壓輸入或後級負載元件RL過電壓輸出的 現象，至於一旦負載元件RL端發生短路現象，基納二極體 ZD1及其前端的分壓電阻R1可負荷大部分的電源功率而 不至危及其他電路元件，然在短路現象排除前則持續消耗 電源功率’甚至發生因功率過度消耗造成電路過熱而終至 2〇危害電路系統中其他電子元件。 +縱使jr以如第二圖所示為另一習用開關電源的一保護 電路2，當負载元件Rpass之負載電流過大或短路時，開關 電晶體Q12則會切斷直流電源VDD的供電， 不會因輸出異常而消耗電源功率，其中電位節點vu為電 4 200840168 路運作正常與否的判斷準位，由軟體偵測後決定是否輸出 啟動電壓以控制開關電晶體Q11之導通或截止；然而當偵 測迴路處於正常運作時，一旦負載元件Rpass之負載電壓 降低以致使前級電晶體Q13、Q14轉態導通，則透過迴授 5電阻R16間接促使開關電晶體qii、Q12截止，反而又使 前級電晶體Q13、Q14轉態截止並再使開關電晶體Qn、 Q12回復導通，若負載元件Rpass上述之負載電壓降低的 問題未移除，則前級電晶體Q13又轉態成導通一直循環下 去，因此造成電路迴授振盪週而復始的出現，同樣無法使 10電路系統正常運作且又因各電晶體不斷的轉態運作而消耗 電路功率。 故設計電源開關的保護電路時除了需考量過熱、過電 壓或過電流等電路保護功能外，往往仍面臨如上述電路功 率消耗及電路迴授振盪等額外產生的電路系統問題，因而 15更增加了電路設計的複雜與困難度。 【發明内容】 因此，本發明之主要目的乃在於提供一 護裝置，^透過軟體控制即能對電源電=22 負載麵：供有效的咼壓及短路保護。 ； 為達成前揭目的，本發明所提供之一電路 可提供-供應電源輸出電源電壓 1衣置係 、冑以輸人端組及—電源輸出端組，該電源輸 5 20 200840168 入端組用以連接該供應·;該味電路具有 端組及-控制端組，該感應端組電性連接該電源輸出端: 及該負載7G件’該控制端組係感應該感應端組達到特 電壓準位而輸出所對應之一第一或一第二控制信號;， 5關電路具有-切換端組及一開關電晶體，該切換端址電性 連接該控制端組，該開關電晶體電性連接該電源輸入端 組’該切換端組接收該第—控制信號即可使該開關電晶體 $通運作，接收$第二控制信號即可使該開關電晶體截止 運作，該穩壓電路具有一限流端組及一箝制元件，該限流 10端組電性連接該箝制元件、該感應端組及上述負載元件， 該開關電晶體導通後上述電源電壓即通過該穩壓電路與該 負載元件電性導通，該箝制元件係維持上述負載元件之跨 電壓低於一高限壓準位，當該限流端組之電壓準位達到一 低限壓準位時，該比較電路即輸出該第二控制信號。 15 【實施方式】 以下，茲配合若干圖式列舉一較佳實施例，用以對本 發明之組成構件及功效作進一步說明，其中所用各圖式之 簡要說明如下： 2〇 第三圖係本發明第一較佳實施例所提供電路保護裝置 之電路方塊示意圖； 第四圖係上述較佳實施例所提供之電路設置示意圖； 第五圖係本發明第二較佳實施例所提供保護電路之電 路不意圖。 200840168 請參閱第三及第四圖所示，為本發明第一較佳實施例 所提供一電路保護裝置3，可提供一供應電源1〇輸出電源 電壓至一負載元件20，係具有一啟動電路3〇、一比較電路 5 40、一開關電路50及一穩壓電路6〇，其中： 該啟動電路30具有一電源輸入端組301、一電源輸出 端組302以及相互並聯之一電容器31及一輸入分壓電阻 32，該電源輸入端組301電性連接該供應電源1〇，該電源 輸出端組302電性連接該比較電路4〇、穩壓電路6〇及負載 ίο元件20,該電容器31之電容板兩側分別電性連接該電源輸 入及輸出端組301、302，本實施例所提供該電容器31具有 特定足夠之電容值且該輸入分壓電阻32具有特定之高阻 值，故當該供應電源10輸入電源電壓的瞬間，該電容器31 可提供為電流短路流通路徑，使電路啟動時即將該供應電 is源10所提供之電源電壓直接自該電源輸出端組3〇2輸出。 該比較電路40具有一感應端組40卜一控制端組4〇2、 一電晶體41以及數個分壓電阻42,該感應端組4〇1電性連 接该電源輸出端組302及負載元件20，該控制端組402電 性連接該開關電路50,該電晶體41之輸入控制端41〇電性 2〇連接該些分壓電阻42;當該感應端組401之電位經各該分 壓電阻42轉換而於該電晶體41之輸入控制端41〇達=二 定之一臨界電位後，即可使該電晶體41之輸出運作於飽和 穩定的狀態，並於該控制端組402產生有穩定電壓準位之 一第一控制信號，當該感應端組401之電位達到特定之一 7 200840168 低限壓準位後，即改變該電晶體41之輸出電位，並於該控 制端組402形成另一電壓準位之一第二控制信號。 5 15 該開關電路50具有一切換端組5(Π、一輸入端組502、 一輸出端組503、一開關電晶體51以及數個分愿電阻52， 該切換端組501電性連接該控制端組402，該輸入端組502 電性連接該供應電源10，該輸出端組503電性連接該穩壓 電路60,該開關電晶體51之輸入控制端μ〇電性連接該些 勿壓電阻52 ,當該切換端組501接收該控制端組4〇2之第 一控制信號後，該開關電晶體51則導通運作於飽和穩定的 狀悲，使該輸入端組502與輸出端組5〇3電性導通，當該 切換端組5〇1接收該控制端組搬之第二控制信號後y該 開關電晶體51則截止運作。 該穩壓電路6G具有-限流端組6(M、—輸出分壓電阻 =箝制元件62，該限流端組6G1電性連接該 二 及該負載元件2G，該開關電晶體二 微小電=壓經該輸出分壓電_之 壓低^之電位’以限制該負載元件2〇之跨電 路不穩定二免準r元件2°之負載電壓在電 電容器31;7二處二置3接設於該供應電源10後，該 電源^1^自_ k供電錢路徑，使啟 體41於電路啟^輸出端組302輸出，以提供該: 、 一即能立導通運麵條件，進一= 20 200840168 使該開關電晶體51導通運作，以將電源電屢由 5〇3輸出經該輸出分廢電阻61至該負載元件2〇;至兮 =容^1逐錢行充電反應後電源輕即可_限流= 和穩=持使該電晶體41之輸出繼續保持運作於飽 15 =該負載元件20之負载龍下降甚至發生電路短路等 現象¥，只要該限流端組6G1之電位低到上述之低 位’亦即使該電晶體41之輸出於該開關電晶體51_之輸入 控制端510 *足使該開關電晶體51導通之臨界電位 到上述觸發該比較電路40輸出第二控制信號之條件，使咳 供應電源1G之電源電壓不再經由該穩壓電路60輸出，而/ 為由該輸人分壓電阻32高阻值的特性以及該電容器31之 充私以承又瞬間形成於該限流端組6〇1與該電源輸入端組 301之間大的跨電壓；當使用者將該限流端組6〇ι斷 開亦即先移除該負載元件2〇以解決其短路問題，此時該 ，入刀£電阻32及該比較電路4〇之分壓電阻42則形成分 壓迴路，可再次使該感應端、組401目到足以觸發該第一控 制信號之電位，故當再次接上正常的負載元件2〇後又可回 複對該負載元件20供應電源電壓的功用。 清參閱如第五圖所示為本發明第二較佳實施例所提供 之-保4電路4’係為上述實施例所提供等效電路之實際電 路兀件，其中一雙極性接面電晶體Q1、一金屬氧化物半導 體Q2及一基納二極體D1分別具有上述實施例之電晶體 4卜開關電晶體51及箝制元件62之功能特性，當然本發 9 20 200840168 明使用之電晶體種類只要以具有電性開關特性的半導體元 件，配合限流端組601之低限壓準位所對應設計使相關電 路導通或截止，皆可達成本發明所需之功效，故本實施例 所應用之半導體開關元件以任何具有良好開關特性的金屬 5氧化物半導體或雙極性接面電晶體皆可相互取代應用；因 此當該雙極性接面電晶體φ之基極電位達到導通臨界電 位時，則可導通該雙極性接面電晶體Q1，並觸發該金屬氧 化物半導體Q2之閘極達到導通臨界電位，以對負載元件 RL供應電源電麈；由於該基納二極體m用以籍制該負載 1〇元件RL之負载電壓不至超過其積納崩潰電壓，則可對該保 護電路4及負载元件RL達到過電壓保護，而當該負載元件 RL之負載電壓分壓於該雙極性接面電晶體Q1之基極電位 小於其臨界電位時，則可同時截止雙極性接面電晶體W及 金屬氧化物半導體Q2’可對該保護電路4形成有效的短路 15保護。 唯’以上所述者’僅為本發明之較佳可行實施例而已， 故舉凡應用本發明說明書及申請專利範圍所為之等效結構 變化，理應包含在本發明之專利範圍内。 200840168 【圖式簡單說明】 f圖係售用電源過電壓防止的電路示意圖； 圖係習用開關電源的保護電路之電路示意圖； 弟一圖係本發明第—較佳實闕所提供電路保護裝置 之％路方塊示意圖； ^四圖係上述較佳實施例所提供之電路設置示意圖； 一第五圖係本發明第二較佳實施例所提供保護電路之電 路示意圖。 10【主要元件符號說明】 15 20 3電路保護裝置 10供應電源 30啟動電路 302電源輸出端組 32輸入分壓電阻 401感應端組 41電晶體 42、52分壓電阻 501切換端組 503輸出端組 60穩壓電路 61輸出分壓電阻 Q1雙極性接面電晶體 D1基納二極體 4保護電路 20負載元件 3 01電源輸入端組 31電容器 40比較電路 402控制端組 410、510輸入控制端 50開關電路 502輸入端組 51開關電晶體 601限流端組 62箝制元件 Q2金屬氧化物半導體 RL負載元件 11200840168 IX. Description of the Invention: [Technical Field of the Invention] The present invention relates to a power supply device, and more particularly to a circuit protection device for power supply output. 5 [Prior Art] Generally, electronic and communication testing equipment or control equipment, etc., mostly use DC switching power supply as the power supply device, and more complicated integrated circuit components are used as the switching circuit for controlling the output of the DC power supply. The component has limited voltage or heat resistance to protect the safety of the switching power supply itself and the load 10. The power supply device is often provided with a protection package such as overheating, overvoltage or overcurrent, as shown in the first figure. A protection circuit 1 for the power over-voltage input is connected to the load element RL by a Zener diode ZD1, and the voltage upper limit of the circuit system is adapted according to the operation of the Zener diode ZD1 to avoid the circuit being not A. The phenomenon of ϊ b-flow switching power supply over-voltage input or rear-stage load element RL over-voltage output occurs. As soon as the RL terminal of the load element is short-circuited, the voltage divider resistor R1 of the Zener diode ZD1 and its front end can carry most of the load. Power supply does not endanger other circuit components, but continues to consume power before the short-circuit phenomenon is eliminated. The circuit is overheated and eventually jeopardizes other electronic components in the circuit. + Even if jr is a protection circuit 2 of another conventional switching power supply as shown in the second figure, when the load current of the load component Rpass is too large or short-circuited, the switching transistor Q12 will cut off the power supply of the DC power supply VDD, and will not The power supply power is consumed due to the abnormality of the output. The potential node vu is the judgment level of the normal operation of the 20084168 road. After the software detects, it determines whether to output the startup voltage to control the on or off of the switching transistor Q11; When the measuring circuit is in normal operation, once the load voltage of the load component Rpass is lowered to cause the front-end transistors Q13 and Q14 to be turned on, the switching transistors qii and Q12 are indirectly turned off by the feedback 5 resistor R16, and the front stage is turned off. The transistors Q13 and Q14 are turned off and the switching transistors Qn and Q12 are turned back on. If the problem of the load voltage reduction of the load component Rpass is not removed, the front transistor Q13 is turned into conduction and continues to circulate. Therefore, the circuit returns to the oscillation cycle and the recurrence occurs. It also fails to make the 10 circuit system operate normally and consumes due to the continuous operation of the transistors. Circuit power. Therefore, in designing the protection circuit of the power switch, in addition to the circuit protection functions such as overheating, overvoltage or overcurrent, it is still faced with additional circuit system problems such as the above-mentioned circuit power consumption and circuit feedback oscillation, so 15 is added. The complexity and difficulty of circuit design. SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide a protective device that can be electrically controlled to a power supply voltage = 22 load surface for effective compression and short circuit protection. For the purpose of achieving the foregoing disclosure, the circuit provided by the present invention can provide - supply power supply output voltage voltage 1 clothing system, 胄 to input terminal group and - power output group, the power input 5 20 200840168 To connect the supply; the taste circuit has an end group and a control end group, the sensing end group is electrically connected to the power output end: and the load 7G piece 'the control end group senses the sensing end group to reach a special voltage level And outputting a corresponding one of the first or a second control signal; the 5 off circuit has a switching end group and a switching transistor, the switching end address is electrically connected to the control end group, and the switching transistor is electrically connected The power input terminal group 'the switching terminal group receives the first control signal to enable the switching transistor to operate, and receives the second control signal to turn off the switching transistor, and the voltage limiting circuit has a limit a current end group and a clamping component, the current limiting 10 end group is electrically connected to the clamping component, the sensing end group and the load component, and the power supply voltage is electrically connected to the load component after the switching transistor is turned on Sexual guidance The clamping component maintains the voltage across the load component below a high voltage limit. When the voltage level of the current limiting group reaches a low voltage limit, the comparison circuit outputs the second control signal. . [Embodiment] Hereinafter, a preferred embodiment will be described with reference to a plurality of drawings for further explaining the components and functions of the present invention, wherein the brief description of each drawing is as follows: 2. The third drawing is the present invention. The circuit block diagram of the circuit protection device provided by the first preferred embodiment; the fourth circuit is a schematic diagram of the circuit arrangement provided by the above preferred embodiment; and the fifth figure is the circuit of the protection circuit provided by the second preferred embodiment of the present invention. Not intended. 200840168 Please refer to the third and fourth figures, which are provided with a circuit protection device 3 according to a first preferred embodiment of the present invention, which can provide a power supply 1 〇 output power supply voltage to a load component 20, and has a startup circuit. 3〇, a comparison circuit 5 40, a switching circuit 50 and a voltage stabilizing circuit 6〇, wherein: the starting circuit 30 has a power input terminal group 301, a power output terminal group 302, and a capacitor 31 and one in parallel with each other. The power supply input terminal group 301 is electrically connected to the power supply terminal group 301. The power supply output terminal group 302 is electrically connected to the comparison circuit 4〇, the voltage stabilization circuit 6〇, and the load device 20, and the capacitor 31 The two sides of the capacitor board are electrically connected to the power input and output terminal groups 301 and 302 respectively. The capacitor 31 provided in this embodiment has a specific sufficient capacitance value and the input voltage dividing resistor 32 has a specific high resistance value. At the moment when the power supply 10 inputs the power supply voltage, the capacitor 31 can be provided as a current short-circuit flow path, so that the power supply voltage supplied from the power supply source 10 is directly output from the power supply when the circuit is started. Group 3〇2 output. The comparison circuit 40 has an inductive end group 40, a control end group 4〇2, a transistor 41, and a plurality of voltage dividing resistors 42. The sensing end group 4〇1 is electrically connected to the power output end group 302 and the load component. 20, the control terminal group 402 is electrically connected to the switch circuit 50, the input control terminal 41 of the transistor 41 is electrically connected to the voltage dividing resistors 42; when the potential of the sensing terminal group 401 is divided by the voltage After the resistor 42 is switched and the input control terminal 41 of the transistor 41 reaches a certain threshold potential, the output of the transistor 41 can be operated in a saturated stable state, and the control group 402 is stable. a first control signal of the voltage level, when the potential of the sensing end group 401 reaches a specific one of the 7200840168 low-limit voltage levels, the output potential of the transistor 41 is changed, and another group is formed at the control end group 402. A second control signal of one of the voltage levels. 5 switch circuit 50 has a switching end group 5 (Π, an input terminal group 502, an output terminal group 503, a switching transistor 51 and a plurality of switching resistors 52, the switching end group 501 is electrically connected to the control The terminal group 402 is electrically connected to the power supply 10, and the output group 503 is electrically connected to the voltage regulator circuit 60. The input control terminal of the switch transistor 51 is electrically connected to the voltage-free resistors. 52. After the switch end group 501 receives the first control signal of the control end group 4〇2, the switch transistor 51 is turned on to operate in saturation stability, so that the input end group 502 and the output end group 5〇 3 electrically conducting, when the switching end group 5〇1 receives the second control signal of the control terminal group, the switching transistor 51 is turned off. The voltage stabilizing circuit 6G has a current limiting end group 6 (M, - output voltage dividing resistor = clamping component 62, the current limiting terminal group 6G1 is electrically connected to the second and the load component 2G, the switching transistor two micro-electricity = the voltage of the output voltage is lower than the voltage Limiting the load component 2〇 across the circuit is unstable. 2 excluding the r component 2° load voltage in the electrical capacitor 31; 7 two places 3 are connected to the power supply 10, the power supply ^1 ^ from the _ k power supply path, the start body 41 is output at the circuit enable output group 302 to provide the: The condition of the conduction surface can be erected, and the switch transistor 51 is turned on, so that the power supply is repeatedly output from 5〇3 through the output split resistor 61 to the load element 2〇; to 兮=容^1 After the charging reaction is performed by the money, the power supply is light. _ Current limiting = and stable = holding the output of the transistor 41 to continue to operate at full 15 = the load of the load component 20 drops or even a short circuit occurs, as long as the The potential of the current limiting end group 6G1 is as low as the above low level' even if the output of the transistor 41 is at the input control terminal 510 of the switching transistor 51_, so that the switching potential of the switching transistor 51 is turned on to trigger the comparison. The circuit 40 outputs a condition of the second control signal, so that the power supply voltage of the cough supply power source 1G is no longer output through the voltage stabilizing circuit 60, and / is a characteristic of the high resistance value of the input voltage dividing resistor 32 and the charging of the capacitor 31 Privately formed and instantly formed in the current limiting group 6〇1 and the power supply A large crossover voltage between the end groups 301; when the user disconnects the current limiting end group 6〇, the load component 2〇 is first removed to solve the short circuit problem, and at this time, the resistance is 32 and The voltage dividing resistor 42 of the comparing circuit 4 forms a voltage dividing circuit, which can make the sensing end and the group 401 again enough to trigger the potential of the first control signal, so when the normal load component 2 is connected again, The function of supplying the power supply voltage to the load element 20 can be restored. Referring to the fifth embodiment, the circuit 4 of the protection 4 provided in the second preferred embodiment of the present invention is the equivalent circuit provided in the above embodiment. The actual circuit component, wherein a bipolar junction transistor Q1, a metal oxide semiconductor Q2, and a kinetic diode D1 respectively have the functional characteristics of the transistor 4 of the above embodiment, the switching transistor 51, and the clamping component 62. And of course, the type of the transistor used in the present invention is as long as the semiconductor element having the electrical switching characteristic is matched with the design of the low-voltage limit of the current limiting end group 601 to make the relevant circuit turn on or off. The work required for invention Therefore, the semiconductor switching element used in the embodiment can be replaced by any metal epoxide semiconductor or bipolar junction transistor having good switching characteristics; therefore, when the base of the bipolar junction transistor φ When the potential reaches the conduction critical potential, the bipolar junction transistor Q1 can be turned on, and the gate of the metal oxide semiconductor Q2 is triggered to reach a conduction critical potential to supply a power supply to the load element RL; The pole body m is used to manufacture the load 1 〇 element RL and the load voltage does not exceed the accumulated breakdown voltage, and the protection circuit 4 and the load element RL can be over-voltage protected, and when the load element RL is loaded with voltage When the base potential of the bipolar junction transistor Q1 is less than its critical potential, the bipolar junction transistor W and the metal oxide semiconductor Q2' can be simultaneously turned off to form an effective short circuit to the protection circuit 4. protection. It is to be understood that the above-mentioned embodiments are merely preferred embodiments of the present invention, and that equivalent structural changes are intended to be included within the scope of the present invention. 200840168 [Simple description of the diagram] f diagram of the circuit for preventing overvoltage of the power supply for sale; diagram of the circuit of the protection circuit of the switching power supply; Figure 1 is a circuit protection device provided by the first embodiment of the present invention FIG. 4 is a schematic diagram of a circuit arrangement provided by the above preferred embodiment; and a fifth diagram is a circuit diagram of a protection circuit provided by the second preferred embodiment of the present invention. 10 [Main component symbol description] 15 20 3 circuit protection device 10 supply power supply 30 startup circuit 302 power supply output group 32 input voltage dividing resistor 401 sensing end group 41 transistor 42, 52 voltage dividing resistor 501 switching end group 503 output group 60 voltage regulator circuit 61 output voltage dividing resistor Q1 bipolar junction transistor D1 kinner diode 4 protection circuit 20 load component 3 01 power input terminal group 31 capacitor 40 comparison circuit 402 control terminal group 410, 510 input control terminal 50 Switching circuit 502 input terminal group 51 switching transistor 601 current limiting end group 62 clamping component Q2 metal oxide semiconductor RL load component 11