M258540 捌、新型說明： 【新型所屬之技術領域】 本新型是有關於一種燈管換流器保護電路，特別是指 一種可防止過低電壓之燈管換流器保護電路。 5 【先前技術】 一般電器產品對電氣及機構設計均訂有相關的產品安 全標準，例如 EN60950 規範之 LCC(Limit Current Circuit) ，又如在EN60065規範中電擊危險（Electric sh〇ck)方面的要 求其中一種測试項目是為測試接觸電流（touch current)之 10 值。 如圖1所示，在一液晶顯示器之背光燈管電路8中， 其所具有之燈管換流器81 (Inverter)主要功能為調整複數燈 管82亮度，燈管82則提供液晶顯示器8之背光源及側光 源之亮度。當應用安規EN60065來測試是否為符合其接觸 15 電流之安全規範時，主要為使用一測試電路9 ,將其電性連 接在燈管換流器81的輸出端來測試，測試電路9之電阻 、電阻r20=5_串聯在Ri〇上，且電容Xc=〇22 # F係跨接在R】G之二端。 若以測試電路9跨接在其中之一燈管82來測試時，由 '〇 於燈管換流器81係經由具安定燈管換流器81作用之電容M258540 新型 Description of the new type: [Technical field to which the new type belongs] The present invention relates to a protection circuit for a lamp tube converter, particularly a protection circuit for a lamp tube converter which can prevent excessive low voltage. 5 [Previous technology] General electrical products have related product safety standards for electrical and institutional design, such as LCC (Limit Current Circuit) according to EN60950, and the requirements of Electric Shock in EN60065. One of the test items is to measure the value of 10 of the touch current. As shown in FIG. 1, in a backlight circuit 8 of a liquid crystal display, a lamp converter 81 (Inverter) has a main function of adjusting the brightness of a plurality of light tubes 82, and the light tube 82 provides the liquid crystal display 8. Brightness of backlight and side light. When the safety standard EN60065 is applied to test whether it meets the safety specifications of contacting 15 currents, it is mainly to use a test circuit 9 and electrically connect it to the output of the lamp tube converter 81 to test. The resistor r20 = 5_ is connected in series on Ri〇, and the capacitor Xc = 〇22 # F is connected across the two ends of R] G. If the test circuit 9 is connected across one of the lamp tubes 82 for testing, the capacitor of the lamp tube converter 81 through the lamp tube converter 81 is used.
Xcoi及Xc〇2連接燈管82，由於此為容抗式輸出方式，因此 背光燈管電路8依舊會正常動作，但被並聯之燈管822會 熄滅，而迴授電流則會取燈管821及測試電路9之合成。 假使燈管換流器81之動作頻率為5〇kHz,且與燈管Li串 M258540 聯之電容Xc〇2阻抗為96 5kQ，而燈管821之阻抗rl為 100kQ，且流經燈管821之電流為6mA，則可得下列近似 解（假設為弦波且忽略雜散元件）·· V丁。Xcoi and Xc〇2 are connected to the lamp tube 82. Because this is a capacitive reactance output method, the backlight tube circuit 8 will still operate normally, but the lamp tube 822 connected in parallel will go out, and the feedback current will take the lamp tube 821. And the synthesis of test circuit 9. Suppose that the operating frequency of the lamp tube inverter 81 is 50 kHz, and the impedance XcO2 of the capacitor connected to the lamp string M258540 is 96 5kQ, and the impedance rl of the lamp 821 is 100kQ, and flows through the lamp 821. If the current is 6 mA, the following approximate solution can be obtained (assuming a sine wave and ignoring stray components). V Ding.
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VlOCU2 +96.5灸2 100 A: 600 - 833(Ko/〇 xco\ 833 ^ 96.5k =8.64(myi) VM=(500+14)* 8.64=4.44( Fo/ί) ίο 15 在測試電路9量測背光燈管電路8時，燈管換流器81 之電壓VT。為833伏特，測試電路9所量測得到之接觸電流 Ixccn為8.64mA。然而，電流通過人體的不同部位及通過不 同的器官會有不同之傷害，若電流經過如心、肺等重要哭 官則危險性更大，故通過心臟電流之安全值一般而言為1〇 以内較為安全，而在安規EN6〇〇65的接觸電流測試結 果依其規範内容便是要求在# A級，故若以上述方式測量得 到之乙⑷為8.64mA，不但無法達到保護人體的安全保障， 也遠遠超過安規EN60065 所訂定之//A級要求。 【新型内容】 因此，本新型燈管換流器保護電路之目的，即在提供 一種保護人體不受電擊的燈管換流器保護電路。 八 本新型之另-目的，在於提供一種符合接觸電流相關 安全規範測試之燈管換流器裝置。 是’本新型之燈管換流器保護電路電性連接於至少 —燈管及-換流器’該換流器電性連接該燈管，用以產生 20 5 10 15 M258540 脈波並調控該燈管之明滅，該換流器保護電路包含. -偵測單元，電性連接於該燈管及該換流器 測該燈管之工作電壓並輸出一制電壓；& 偵 早7° $性連接於該偵測單元及m&n 4 間，用以接收自該谓測單元輸入之備測電堡，並愈ιΐ ，較，當該偵輸低於該預定電壓時，該::較單： 輸出一保護信號給該換流器，使該換流器停止工作 使該燈管熄滅。 而 【實施方式】 有關本新型之前述及其他技術内容、特點與功效 以下配合參考圖式之較佳實施例料細說明中，將可 的明白。 < 如圖2所*，為本新型燈f換流器保護電路丨之寸 佳實:例’其電性連接於至少—燈管2及―換流器3之^ ’換，器3用以產生脈波並調控燈管2之明滅且電性連接 於燈管2。以本較佳實施例而言’燈管2數目可為—支或複 數支’由於是與液晶顯示器(圖未示)的背光顯示電路連接， 故應為複數支燈管2，而—組燈管換流器保護電路i可由複 數燈管2共用之’亦或各燈管2分別搭配一組燈管換流器 保護電路i。但為了方便說明起見，以下所述之燈管2數目° 以二支來表示，燈管21、22共用一組燈管換流器保護電路 1 〇 配合圖2、3所示，換流器保護電路丨包含一偵測單元 11及一比較單元12，债測單元U之兩端分別電性連接於燈 20 M258540 管21、22及比較單亓〗？ 陳v ，用以偵測燈管21、22之τ你+ 反Va、Vb，比較單元】？ 之工作迅 器3二者之間，用歧 < 性連接於偵測單元U及換流 。 收自偵測單元11輸入之偵測電壓％ …”中^則早凡11具有二電容C1、C2,電容以奸 :2!並聯、電容C2係與燈管再： 並聯電容… a b主要為考慮為避免功韋夕赀紅 用雷阳八茂士h U免功率之扣耗，然而，亦可以 ίο 15 “ 式來偵測燈管2的工作電m，將立合 成-債測胸給比較單元12作後續的控制。… …而=較早凡12具有-與偵測單元"串接之二極體m 較單元12更具有♦極r D二广…貞測電壓Vs’比 ，、 體m串接之PNP型電晶體121 電日日體121之基極B雷地 B電性連接於二極體D1，電晶體121 ^集極C則電性連接於一電阻R3及換流器3，而一預定電 W加載於電晶體⑵之射極E。此外，在二極體D1 關測早兀11之間，並聯有一電容C3及-二極體D2，電 谷C3及二極體D2另—端則接地；在二極體〇1及電晶體 121之間’具有一接點a ’接點a及二極體D1之間並聯有 電奋C4及電阻Rl，電容C4及電阻幻之另一端則接 而接』a及电曰曰體121的射極E之間則有一電容c5及 一電阻R2跨接於兩者之間’電晶體ΐ2ι之集極c經電阻 R3電性連接至換流器3。 特別說明的是，亦可使用一比較器配合預定電壓Vref 20 M258540 來取代上述比較單元12之電路來達成相同的效果，而此為 熟習該項技藝者易於施行者，故不再贅述之。 ^藉由^述構件，彳言兒明該較佳實施例的實際應用方式 ，當制單U制到之摘測電壓％過低時，亦即傾測 电[Vs低於所加載在電晶體12丨之射極e之預定電壓we b(VS-VD<Vref_VBE 近似於 Vs<Vref)，則二極體川被 反向偏£而不導通，電晶體121則由集極G輸出—保護信 號，亦即將-近似於Vref的電壓值〜=vref_v_)經由電 ίο 15 阻R3輸出給換流器3之波寬調變控制器”，使換流器3停 止工作，進而使燈管2熄滅。 在本較佳實施例中，波寬調變控制器31為使用一例如 TLU51或其相當功能之控制冗，其具有一截止時間控制腳 ^deaci _e control pin) ’則當％ < ^時，輸入保護電 重VPT至控制Ic之截止時間控制腳位’進而使換流器3停 =作並且將燈官2媳滅掉。然而，控制K亦有電源開 、短路料或過電壓保料之相關控輯位，亦可應用 本新型之k官換流器保護電路i所輸出之保護電壓νρτ來控 制上述腳位而使換流器3停止其運作。 工 歸納上述’本新型之燈管換流器保護電路i電性連接 :換流器3及複數燈管2之間，以預定電壓㈣之設定， 當偵測單元11偵測到之偵測電壓vs過低，亦即Vs又小於 ^時，則以輸出保護電壓VpT的方式關閉換流器3，不作 R 了一種保護人體不受電擊的燈管換流器保護方式，同 日寸也符合接觸電流相關安全規制試，相安全的功效。 20 M258540 惟以上所述者，僅為本新型之較佳實施例而已，當不 能以此限定本新型實施之範圍，即大凡依本新型申請專利 範圍及新型說明書内容所作之簡單的等效變化與修飾，皆 應仍屬本新型專利涵蓋之範圍内。 【圖式簡單說明】 圖1是一電路方塊圖’說明一習知液晶顯示器之背光 燈管電路以-測試電路來測試是否為符合其接觸電流之安 全規範； 10 圖2 電路之— 及 是-電路方塊圖’說明本新型之燈管換流器保護 較佳實施例’其電性連接於二燈管及一換流器； M258540 【圖式之主要元件代表符號說明】 1 燈管換流器保護電 33 變壓器 路 34 電流迴授電路 11 偵測單元 C1、 C2 、 C3 、 C4 12 比較單元 電容 121 電晶體 D1、 D2二極體 2、21 、11 R1、 R2電阻 燈管 Va、 Vb工作電壓 3 換流器 Vpt 保護電壓 31 波寬調變控制器 Vref 預定電壓 32 功率級電路 Vs 偵測電壓 C5 10VlOCU2 +96.5 moxibustion 2 100 A: 600-833 (Ko / 〇xco \ 833 ^ 96.5k = 8.64 (myi) VM = (500 + 14) * 8.64 = 4.44 (Fo / ί) ίο 15 Measured in the test circuit 9 When the backlight circuit 8 is used, the voltage VT of the lamp converter 81 is 833 volts, and the contact current Ixccn measured by the test circuit 9 is 8.64 mA. However, the current passes through different parts of the human body and through different organs. There are different injuries. If the current passes through important crying officers such as the heart and lungs, it is more dangerous. Therefore, the safety value of passing the heart current is generally safer within 10, and the contact current test in safety standard EN60065 As a result, according to its specifications, it is required to be in the level of #A. Therefore, if the acetamidine measured in the above manner is 8.64mA, it will not only be able to meet the safety guarantee for protecting the human body, but also far exceed the // A level requirements set by the safety standard EN60065. [New content] Therefore, the purpose of the new lamp tube inverter protection circuit is to provide a lamp tube inverter protection circuit that protects the human body from electric shock. Another object of this new model is to provide a conformable contact Lamps for current-related safety testing The inverter device is 'the new type of lamp tube inverter protection circuit is electrically connected to at least-the lamp tube and-the inverter', the inverter is electrically connected to the lamp tube to generate 20 5 10 15 M258540 pulses The converter protects the circuit and controls the light on and off. The detection unit is electrically connected to the light tube and the converter measures the working voltage of the light tube and outputs a regulated voltage; & As early as 7 °, it is sexually connected between the detection unit and m & n 4 to receive the test battery input from the so-called measurement unit, and it will be more stable. Compared with when the detection input is lower than the predetermined voltage, This :: Comparison: Output a protection signal to the inverter, stop the inverter from working and extinguish the lamp. [Embodiment] The aforementioned and other technical contents, features and effects related to this new model are referenced below. In the detailed description of the preferred embodiment of the figure, it will be understood. ≪ As shown in Figure 2 *, this new type of lamp f inverter protection circuit is very good: Example 'It is electrically connected to at least- Lamp tube 2 and "inverter 3" switch, device 3 is used to generate pulse wave and regulate the light and light of lamp tube 2 and electrical Connected to the lamp tube 2. According to the present preferred embodiment, the number of the lamp tube 2 may be-a branch or a plurality of tubes. Since it is connected to a backlight display circuit of a liquid crystal display (not shown), it should be a plurality of tubes. 2, and the group of lamp tube inverter protection circuit i can be shared by a plurality of lamp tubes 2 or each lamp tube 2 is respectively matched with a group of lamp tube converter protection circuit i. But for the convenience of description, the following The number of lamp tubes 2 is represented by two tubes. The lamp tubes 21 and 22 share a group of lamp tube converter protection circuits 1 〇 As shown in FIGS. 2 and 3, the converter protection circuit includes a detection unit 11 and A comparison unit 12, the two ends of the debt measurement unit U are respectively electrically connected to the lamps 20, M258540, tubes 21, 22 and a comparison unit? Chen v, used to detect τyou + anti-Va, Vb of the lamps 21, 22, comparison unit]? The working scanner 3 is connected between the detection unit U and the commutation unit by means of ambiguity. The detection voltage% input from the detection unit 11 ... "In ^, the early 11 has two capacitors C1, C2, and the capacitance is 2: in parallel, the capacitor C2 is connected to the lamp, and the capacitor is connected in parallel ... ab is mainly considered In order to avoid the loss of power by using Leiyang Baomaoshi h U to avoid the power loss, however, it is also possible to detect the working electricity m of lamp 2 by using a 15 ”formula, and to synthesize a debt-determining chest to the comparison unit. 12 for subsequent control. … And = Early where the 12 has a -diode m connected in series with the detection unit " Pole r D is wider than the unit 12 ... The ratio of the measured voltage Vs', the PNP type is connected in series with the body m Transistor 121 The base B of mine 121 is electrically connected to diode D1, and transistor 121 ^ collector C is electrically connected to a resistor R3 and inverter 3, and a predetermined power W Loaded on the emitter E of the transistor. In addition, a capacitor C3 and -diode D2 are connected in parallel between the diode D1 and the early detection unit 11. The other end of the valley C3 and the diode D2 is grounded; the diode 01 and the transistor 121 are grounded. There is a contact point a between the contact point a and the diode D1. In parallel, there is a capacitor C4 and a resistor R1, and the capacitor C4 and the other end of the resistor are connected in parallel. A capacitor c5 and a resistor R2 are connected across the electrode E, and a collector c of the transistor 2m is electrically connected to the inverter 3 via the resistor R3. In particular, it is also possible to use a comparator with a predetermined voltage Vref 20 M258540 instead of the circuit of the above-mentioned comparison unit 12 to achieve the same effect, and this is easy for those skilled in the art, so it will not be described again. ^ By means of the description, the practical application method of the preferred embodiment will be explained. When the test voltage% of the system U is too low, that is, the measured voltage [Vs is lower than that of the transistor 12 丨 the predetermined voltage we b of the emitter e (VS-VD < Vref_VBE is similar to Vs < Vref), the diode is reverse biased and does not conduct, and the transistor 121 is output by the collector G-protection signal , That is, the voltage value of ~ approximately Vref ~ = vref_v_) is output to the wave width modulation controller of the inverter 3 through the electric resistance 15, so that the inverter 3 stops working, and then the lamp 2 is extinguished. In the preferred embodiment, the bandwidth modulation controller 31 uses a control redundancy such as TLU51 or its equivalent, which has a cut-off time control pin ^ deaci _e control pin) 'when% < ^, Input the protection voltage VPT to the control time of the Ic control pin, and then stop the inverter 3 and turn off the light officer 2. However, the control K also has power on, short circuit or overvoltage protection. The relevant control bits can also be controlled by the protection voltage νρτ output by the new-type k-converter protection circuit i. Pin to stop the operation of the inverter 3. According to the above-mentioned 'the new type of lamp tube inverter protection circuit i is electrically connected: between the inverter 3 and the plurality of lamp tubes 2, set at a predetermined voltage ，, When the detection voltage detected by the detection unit 11 is too low, that is, Vs is less than ^, the inverter 3 is closed by outputting the protection voltage VpT, and R is not used to protect the human body from electric shock. The protection method of the inverter is also in compliance with the safety regulation test of contact current in the same day, and the efficacy of phase safety. 20 M258540 However, the above is only the preferred embodiment of the new model, and it cannot be used to limit the implementation of the new model. The scope, that is, the simple equivalent changes and modifications made according to the scope of the patent application of the new model and the content of the new specification, should still fall within the scope of the new patent. [Simplified illustration of the drawing] Figure 1 is a circuit block diagram ' Explain that the backlight circuit of a liquid crystal display uses a test circuit to test whether it meets the safety specifications of its contact current; 10 Figure 2 Circuits—and yes—circuit block diagram 'illustrates the new type of lamp tube commutation The preferred embodiment of the device protection is that it is electrically connected to two lamps and a converter; M258540 [Description of the main components of the diagram] 1 Lamp tube protector 33 Transformer circuit 34 Current feedback circuit 11 Detection Measurement unit C1, C2, C3, C4 12 Comparison unit capacitance 121 Transistor D1, D2 Diode 2, 21, 11 R1, R2 Resistance lamp Va, Vb Working voltage 3 Converter Vpt Protection voltage 31 Wave width modulation Controller Vref predetermined voltage 32 power stage circuit Vs detection voltage C5 10