200850067 九、發明說明： 【發明所屬之技術領域】 本發明係有關於一種用以偵測在一電子鎭流器中之 BJT(雙載子接面電晶體）的實際截止信號之方法及一種使 用該方法之對應電子鎭流器。 【先前技術】 第1圖係與本發明最有關的一習知技藝電子鎭流器之部 分電路。該電子鎭流器包括一驅動變壓器T1、兩個基本單 元及一上側BJT S1與一下側BJT S2，該上側BJT S1與該 下側BJT S2構成一半橋式電路，其中在BJT S1與BJT S2 間界定該半橋式（HB)電路之一中心點Μ，該中心點在一側 上經由一串列電路（包括一電容器C2及一二極體D1 (—二 極體或一齊納二極體））耦接至一參考電位（接地），以及在第 二側上經由一電容器C3及一電感器L2耦接至一電燈（複數 個電燈），此外，該中心點Μ亦經由一電阻器R2連接至一 用以供應脈衝至該變壓器Τ1以驅動該等開關S1及S2之 ΗΒ控制單元。該ΗΒ控制單元具有一耦接至電容器C2與 二極體D 1間之連接點Ν的供應端VCC，以及藉由該電阻 器R2偵測在該中心點Μ上之電壓變化以調整脈衝輸出之 振幅。如第1圖所示，使用輸出OUT 1以驅動該上側開關 S1，以及使用輸出0UT2以驅動該下側開關S2。 在此情況中，在輸出0UT2從高位準變化至低位準之時 刻與MS接腳上之測量電壓從零上升達到某一正値之時刻 間的時間Toff代表該下側B〗T S2之實際儲存及下降時間， 以及藉由保持該時間Toff在一固定値上以調整基極電流。 200850067 藉由較低1C輸出電壓補償在正常操作中因BJT容差或高溫 所造成之該B JT S 2的較長儲存時間，反之亦然。1C以相同 標準一步一步地每一個週期（每一週期一步）調整兩個輸出 及在最小與最大輸出電壓値間具有某幾步。該兩個輸出之 振幅係相同的及在一輸出之關閉及另一輸出之導通間具有 一固定至某一數値之停滯時間（deadtime)。亦可考慮一（分 離或整合）半導體半橋式驅動器以取代該變壓器。特別地， 可使用任何型態之電開關以取代BJT。 BJT在該半橋式電路中伴演開關之角色。在導通中，它 們應該是飽和的以最小化其功率損失，以及反之係不啓動 的。通常，較深飽和將導致較長儲存時間，反之亦然。該 MS接腳只是用以測量該下側B〗T S2之實際儲存及下降時 間，以便評估飽和狀態。然而，由於BJT之容差，在半橋 式電路中之兩個BJT的增益及儲存時間通常不是相同的。 該上側BJT之增益可能比該下側BJT之增益小，以及該上 側BJT之實際儲存時間可能比該下側B〗T之實際儲存時間 短。因此，當驅動電流適合於該下側B〗T時，對該上側BJT 可能是不夠的，該上側BIT可能被稍微啓動，導致B〗T開 關之較高功率損失及有時電燈閃爍。在這個方面，習知技 藝建議調整驅動變壓器及基本單元以確保對該上側B〗T有 足夠驅動電流，其中該上側BJT之增益及儲存時間在BJT 規格中係最小的，然而該下側BJT之增益及儲存時間係最 大的（最差的BJT組合）。然而，此解決方法通常使1C輸出 保持最小，此表示沒有調整功能。 此外，當在該半橋式電路中之兩個B〗T正常工作時，它 200850067 們是在零電壓切換條件中操作（幾乎沒功率損失，參照表1 之左側）。然而，在這些BJT開關中經常具有某些功率損失， 此將使BJT開關變熱。溫度對BJT之儲存時間具有影響， 以及通常較高溫度使儲存時間變長。當儲存時間變得較 長，則要使1C輸出之保滯時間保持不變，因而可能不夠。 結果，在一 B〗T之集極與射極間之電壓下降至零伏特前， 可能已導通該 BJT(該開關具有功率損失，參照表1之右 側）。BJT中之更多功率損失將相關地造成較長儲存。這是 一種缺點，此缺點會最後損壞該兩個B】T，在此方面，習 知技藝建議調整驅動變壓器及基本單元以相對地使儲存時 間變短，以及改善冷卻條件以儘量維持B〗T的溫度。然而， 此解決方法無法絕對地確保在該兩個BJT開關變熱時有足 夠的停滯時間，以及由於BJT之容差，BJT之增益及儲存 時間不是均稱的。 【發明內容】 因此，本發明所要解決之技術問題係提供一種用以偵測 在一電子鎭流器中之B〗T的實際截止信號之改良方法及一 種對應電子鎭流器。根據BJT之實際截止信號的偵測，可 經由進一步改善實現在該電子鎭流器內之較佳驅動控制。 依據本發明所提供之用以偵測在一電子鎭流器中之BJT的 實際截止信號之方法，該電子鎭流器包括一半橋式電路， 該半橋式電路係由以端對端之串聯方式連接之一第一 BJT 及一第二B〗T所構成，該第一及第二BJT之基極係分別以 一第一基本單元及一第二基本單元來控制，以便輪流導通 該第一及第二BJT; — HB控制單元，用以依據在該半橋式 200850067 電路之輸出端上的電壓輸出信號調整分別被供應至該第一 及第二基本單元之控制脈衝，其中該電壓輸出信號一方面 被提供至一電燈及另一方面經由一電容器及一反向二極體 接地，以及在該電容器與該二極體間之連接點耦接至該HB 控制單元之供應端。依據本發明，該HB控制單元經由測 量在該連接點上之電壓的陡峭斜率以測量該第一及/或第 二BJT之實際截止信號。由於該電壓之陡峭斜率比在該原 始偵測點Μ上所直接獲得之電壓斜率更準確地靠近在點Μ 上之電壓的暫態位置的事實，因而可輕易地且準確地測量 BJT之實際截止信號。 最好，藉由分別測量在用以截止該第一及第二BIT之每 一 B】T的控制脈衝之側邊與在該連接點上所因而呈現之電 壓的對應陡峭斜率間之時間，可獲得該第一及第二B】T之 第一及第二儲存時間。在此方式中，可更輕易地及準確地 偵測該第一及第二B JT之第一及第二儲存時間。 最好，該HB控制單元比較該第一與第二儲存時間，以 及該較短儲存時間用以調整基極電流調整用之1C輸出的 振幅。在此方式中，具有較短儲存時間之B JT T供應有適當 電流，以及在導通中維持飽和。當導通時，具有較長儲存 時間之另一 B JT將以最小功率損失使其在良好導通情況中 飽和。在此解決方法中，亦具有下面優點：如果該較短儲存 時間小於一在1C內部或外部所設定之固定値，則1C將增 加輸出脈衝之振幅，反之亦然。 取代或附加上述解決方法，該HB控制單元比較該第一 與第二儲存時間，以及該較長儲存時間用以調整1C輸出之 200850067 停滯時間，以確保經常有足夠且適當停滯時間。最好，依 據每一週期之較長儲存時間計算及調整該停滯時間，因 此，可依據例如停滯時間=ax該較長儲存時間+b之公式計 算及調整該停滯時間，其中a及b係固定値。在另一情況 中，先將該停滯時間保持固定，以及當該較長儲存時間超 過一固定値c時，增加該停滯時間至d，然而如果該較長儲 存時間小於該固定値c，則減少該停滯時間至該原始値。 本發明所提供之電子鎭流器包括一半橋式電路，該半橋 r ! 式電路係由以端對端之串聯方式連接之一第一 b〗t及一第 二BJT所構成，該第一及第二Β】Τ之基極係分別以一第一 基本單元及一第二基本單元來控制，以便輪流導通該第一 及第二BJT; — ΗΒ控制單元；用以依據在該半橋式電路之 輸出端上的電壓輸出信號，調整分別被供應至該第一及第 二基本單元之控制脈衝，其中該電壓輸出信號一方面被提 供至一電燈及另一方面經由一電容器及一反向二極體接 地，以及在該電容器與該二極體間之連接點耦接至該ΗΒ j 控制單元之供應端。依據本發明，該連接點亦耦接至該ΗΒ 控制單元之測量接腳，致使該ΗΒ控制單元可經由測量在 該連接點上之電壓的陡峭斜率以測量該第一及/或第二B J Τ 之實際截止信號。如有關上述解決方法中所述，該電壓之 陡峭斜率比在該原始偵測點Μ上所直接獲得之電壓斜率更 準確地靠近在點Μ上之電壓的暫態位置，致使可更快速地 且準確地測量B JT之實際截止信號。同樣地，針對上述方 法之改善所顯示之優點效果明顯可應用至下面所要描述之 本發明的電子鎭流器的改善。 -10- 200850067 最好，該HB控制單元藉由分別測量在用以截止該第一 及第二B]T之每一 B】T的控制脈衝之側邊與在該連接點上 所因而呈現之電壓的對應陡峭斜率間之時間可獲得該第一 及第二B〗T之第一及第二儲存時間。在此方式中，可更輕 易地且準確地偵測該第一及第二BJT之第一及第二儲存時 間。 在該電子鎭流器中，該HB控制單元比較該第一與第二 儲存時間，以及該較短儲存時間用以調整基極電流調整用 之1C輸出的振幅。如果該較短儲存時間小於一在1C內部 或外部所設定之固定値，則1C將增加輸出脈衝之振幅，反 之亦然。 在該電子鎭流器中，該HB控制單元比較該第一與第二 儲存時間，以及該較長儲存時間用以調整1C輸出之停滯時 間，以確保經常有足夠且適當停滯時間。該HB控制單元 可依據每一周期之較長儲存時間計算及調整該停滯時間。 例如：該HB控制單元依據停滯時間=ax該較長儲存時間+b 之公式計算及調整該停滯時間，其中a及b係固定値。在 ί， 另一情況中，該HB控制單元可先保持固定之停滯時間， 然後當該較長儲存時間超過一固定値c時，增加該停滯時 間至d，以及如果該較長儲存時間小於該固定値c，則減少 該停滯時間至該原始値。 在該電子鎭流器中，該連接點可經由一電阻器連接至該 HB控制單元之測量接腳MS。 該Η B控制單元之控制脈衝可經由一驅動變壓器分別連 接至該弟一^及弟一*基本單兀’以便提供用以輪流截止該第 -11- 200850067 一及第二BJTs之控制脈衝。在另一情況中，該HB控制單 元之控制脈衝可經由一半導體爲基礎之半橋式驅動器分別 耦接至該第一及第二基本電路，以便提供用以輪流截止該 第一及第二BJT之控制脈衝。 將參考所附圖式以詳細說明本發明。 【實施方式】 第1圖及表1已描述於背景技藝中及將不再詳盡闡述。 參照至第2圖中所示之本發明的電子鎭流器。該電子鎭 f 流器大部分相似於第1圖中所示之習知技藝電子鎭流器。 然而，不同之處在於：該測量接腳MS經由一電阻器R3連接 至該電容器C 2與二極體D 1間之連接點N，以及係用以測 量在該連接點N上之電壓信號，該信號係顯示於第3圖中 作爲Ch4。可從第3圖之曲線圖看出電壓V-N(在該連接點 N上之電壓Ch4)在電壓V-M(在該點Μ上之電壓）之正與負 斜率的起始點上立即改變，亦即，電壓V -Ν具有一從零至 正之陡峭變化（陡峭斜率）與一從正至零之陡峭變化。該電 壓V-M(在該點Μ上之電壓）之正與負斜率係因BJT集極電 流之截止所造成。此特性表示電壓V - Ν之陡峭斜率信號可 用以偵測BJT之實際截止信號，以及因此可藉由進一步與 該驅動脈衝之截止斜率做比較以計算BJT之實際儲存時 間。 如第4圖中所示，游標cursl係在輸出脈衝〇UT1之負斜 率處，以及游標curs2係在電壓V-N之負斜率處（亦在該上 側BJT集極電流之負斜率處）。因而，將 cursl 與 curs2 間 之時間界定成爲該上側B J T S 1之實際儲存時間T s 1，該實 -12- 200850067 際儲存時間Tsl在此爲97 6.0-0.0 = 97 6.0ns。同樣地，如第5 圖中所示，游標ciirsl係在輸出脈衝OUT2之負斜率處，以 及游標curs2係在電壓V-N之正斜率處（亦在該下側B】T集 極電流Chi之負斜率處）。因而，將cursl與curs2間之時 間界定成爲該下側BIT S2之實際儲存時間Ts2，該儲存時 間Ts2在此爲1.016-0.0=l.〇16ps。可看出該下側BJT之實 際儲存時間大於該上側 B〗T之實際儲存時間，以及 Ts2-Tsl = 1.016ps-976.0ns = 40.0ns 〇 … 清楚地，該連接點N連接至該HB控制單元之測量接腳 MS，致使該HB控制單元藉由測量在該連接點N上之電壓 的陡峭斜率可準確地測量該第一及/或第二Β〗Τ S1及S2之 實際截止信號。 再者，該HB控制單元藉由測量在一方面用以截止該第 一及第二BJTs S1及S2之每一 BJT的控制脈衝之側邊〇UT1 及OUT2與另一方面在該連接點N上所因而出現之電壓的 對應陡峭斜率間之時間，可獲得該第一及第二BJT S1及S2 之第一及二儲存時間Tsl及Ts2。 爲了使該兩個B Ji T s S 1及S 2具有適當驅動電流而無視於 該參數容差，該HB控制單元比較該第一與第二儲存時間， 以及該較短儲存時間用以調整基極電流調整用之IC輸出 的振幅。在此方式中，具有較短儲存時間之BJT供應有適 當電流，以及在導通中維持飽和。當導通具有較長儲存時 間之另一 B〗T時，將以最小功率損失使其在良好導通情況 中飽和，因而避免BIT開關之較高功率損失及電燈閃爍。 特別地，如果該較短儲存時間小於一在該1C內部或外部所 -13 - 200850067 設定之固定値，該1C將相應地增加輸出脈衝之振幅，反之 亦然。 爲了避免較長儲存時間所造成之不充分停滞時間及因而 最後損壞該兩個BJTs S 1及S2而無視於溫度變化，該HB 控制單元比較該第一與第二儲存時間，以及較長儲存時間 用以調整1C輸出之停滯時間，以確保經常有足夠且適當停 滯時間。具體地，該HB控制單元依據每一周期之較長儲 存時間計算及調整該停滯時間。特別地，該HB控制單兀 r 可依據停滯時間=ax該較長儲存時間+b之公式計算及調整 該停滯時間，其中a及b係固定値。在另一情況中，該HB 控制單元可先保持固定之停滯時間，然後當該較長儲存時 間超過一固定値c時，增加該停滯時間至d，以及如果該較 長儲存時間小於該固定値c，則減少該停滯時間至該原始 値。 對於本發明之電子鎭流器，該HB控制單元之控制脈衝 可經由一驅動變壓器T1分別耦接至該第一及第二基本單 元，致使提供用以輪流截止該第一及第二BJTs S1及S2之 控制脈衝。此外，該驅動變壓器T 1可以以一半導體爲基礎 之半橋式驅動器來取代。 從上面描述可推知本發明已提供一種可更安全地操作之 電子鎭流器及一種用以操作該電子鎭流器之方法。 【圖式簡單說明】 第1圖顯示該習知技藝電子鎭流器之部分電路； 第2圖顯示本發明之電子鎭流器的部分電路； 第3圖顯示依據本發明所測量之電壓的曲線圖·， -14-200850067 IX. Description of the Invention: [Technical Field] The present invention relates to a method for detecting an actual cutoff signal of a BJT (dual-carrier junction transistor) in an electronic choke and a use thereof The corresponding electronic choke of the method. [Prior Art] Fig. 1 is a partial circuit of a conventional art electronic choke which is most relevant to the present invention. The electronic choke includes a driving transformer T1, two basic units and an upper side BJT S1 and a lower side BJT S2, and the upper side BJT S1 and the lower side BJT S2 form a half bridge circuit, wherein between the BJT S1 and the BJT S2 Defining a center point 该 of the half-bridge (HB) circuit, the center point being on one side via a series of circuits (including a capacitor C2 and a diode D1 (-diode or a Zener diode) Is coupled to a reference potential (ground), and coupled to a lamp (a plurality of lamps) via a capacitor C3 and an inductor L2 on the second side, and the center point is also connected via a resistor R2 Up to the control unit for supplying pulses to the transformer Τ1 to drive the switches S1 and S2. The ΗΒ control unit has a supply terminal VCC coupled to a connection point 电容器 between the capacitor C2 and the diode D1, and the voltage change at the center point 侦测 is detected by the resistor R2 to adjust the pulse output. amplitude. As shown in Fig. 1, the output OUT 1 is used to drive the upper switch S1, and the output OUT2 is used to drive the lower switch S2. In this case, the time Toff between the time when the output OUT2 changes from the high level to the low level and the time when the measured voltage on the MS pin rises from zero to a certain positive value represents the actual storage of the lower side B T T T2 And the fall time, and by adjusting the time Toff on a fixed turn to adjust the base current. 200850067 The longer storage time of the B JT S 2 due to BJT tolerance or high temperature during normal operation is compensated by the lower 1C output voltage, and vice versa. The 1C adjusts the two outputs step by step in each cycle (one step per cycle) with the same standard and has some steps between the minimum and maximum output voltages. The amplitudes of the two outputs are identical and have a dead time fixed to a certain number between the turn-off of one output and the turn-on of the other output. A semiconductor (separate or integrated) semiconductor half-bridge driver can also be considered to replace the transformer. In particular, any type of electrical switch can be used in place of the BJT. BJT plays the role of a switch in this half-bridge circuit. In conduction, they should be saturated to minimize their power loss and vice versa. Generally, deeper saturation will result in longer storage times and vice versa. The MS pin is only used to measure the actual storage and fall time of the lower side B T T2 to evaluate the saturation state. However, due to the tolerance of the BJT, the gain and storage time of the two BJTs in the half-bridge circuit are typically not the same. The gain of the upper BJT may be smaller than the gain of the lower BJT, and the actual storage time of the upper BJT may be shorter than the actual storage time of the lower B T. Therefore, when the drive current is suitable for the lower side B T, the upper BJT may not be sufficient, the upper BIT may be slightly activated, resulting in a higher power loss of the B T switch and sometimes flashing of the electric light. In this respect, the prior art suggests adjusting the drive transformer and the base unit to ensure sufficient drive current for the upper side B, where the gain and storage time of the upper BJT is the smallest in the BJT specification, whereas the lower BJT Gain and storage time are the largest (worst BJT combination). However, this solution usually keeps the 1C output to a minimum, which means there is no adjustment function. In addition, when two B's in the half-bridge circuit are operating normally, it is operating in the zero voltage switching condition (nearly no power loss, see the left side of Table 1). However, there are often some power losses in these BJT switches that will heat the BJT switch. Temperature has an effect on the storage time of the BJT, and usually higher temperatures make the storage time longer. When the storage time becomes longer, it is not enough to keep the 1H output dead time constant. As a result, the BJT may have been turned on before the voltage between the collector and the emitter of T B has dropped to zero volts (the switch has power loss, see the right side of Table 1). More power loss in the BJT will in turn cause longer storage. This is a disadvantage that would eventually damage the two B]T. In this regard, the prior art suggests adjusting the drive transformer and the base unit to relatively short the storage time and improving the cooling conditions to maintain B&T as much as possible. temperature. However, this solution does not absolutely ensure that there is sufficient dead time when the two BJT switches become hot, and that the gain and storage time of the BJT are not uniform due to the tolerance of the BJT. SUMMARY OF THE INVENTION Therefore, the technical problem to be solved by the present invention is to provide an improved method for detecting an actual cutoff signal of B T in an electronic choke and a corresponding electronic choke. According to the detection of the actual cutoff signal of the BJT, better drive control in the electronic choke can be achieved through further improvement. According to the present invention, there is provided a method for detecting an actual cutoff signal of a BJT in an electronic choke, the electronic choke comprising a half bridge circuit, the half bridge circuit being connected in series by end to end The first BJT and the second B-T are connected by a mode, and the bases of the first and second BJTs are respectively controlled by a first basic unit and a second basic unit, so as to turn on the first And a second BJT; - HB control unit for adjusting control pulses respectively supplied to the first and second basic units according to a voltage output signal at an output of the half bridge 200850067 circuit, wherein the voltage output signal One side is provided to a lamp and the other side is grounded via a capacitor and a reverse diode, and a connection point between the capacitor and the diode is coupled to the supply end of the HB control unit. In accordance with the present invention, the HB control unit measures the actual cutoff signal for the first and/or second BJT by measuring the steep slope of the voltage at the junction. Since the steep slope of the voltage is closer to the transient position of the voltage at the point 更 more accurately than the voltage slope directly obtained at the original detection point ,, the actual cutoff of the BJT can be easily and accurately measured. signal. Preferably, by measuring the time between the side of the control pulse for cutting off each of the first and second BITs and the corresponding steep slope of the voltage thus presented at the connection point, Obtaining the first and second storage times of the first and second B]T. In this manner, the first and second storage times of the first and second B JTs can be detected more easily and accurately. Preferably, the HB control unit compares the first and second storage times, and the shorter storage time is used to adjust the amplitude of the 1C output for base current adjustment. In this manner, B JT T with a shorter storage time is supplied with the appropriate current and maintains saturation during conduction. When turned on, another B JT with a longer storage time will saturate it in good conduction with minimal power loss. In this solution, there is also the advantage that if the shorter storage time is less than a fixed chirp set inside or outside 1C, 1C will increase the amplitude of the output pulse and vice versa. Instead of or in addition to the above solution, the HB control unit compares the first and second storage times, and the longer storage time is used to adjust the 200850067 dead time of the 1C output to ensure that there is often sufficient and appropriate dead time. Preferably, the dead time is calculated and adjusted according to the longer storage time of each cycle. Therefore, the dead time can be calculated and adjusted according to the formula of the dead time = ax long storage time + b, where a and b are fixed value. In another case, the stagnation time is first fixed, and when the longer storage time exceeds a fixed 値c, the stagnation time is increased to d, but if the longer storage time is less than the fixed 値c, the reduction is decreased. The stagnation time is up to the original 値. The electronic choke provided by the present invention comprises a half bridge circuit, which is composed of a first b 〖t and a second BJT connected in series in an end-to-end manner, the first And the second base of the crucible is controlled by a first basic unit and a second basic unit, respectively, to turn on the first and second BJTs in turn; the control unit is configured to be based on the half bridge a voltage output signal at an output of the circuit, the control pulses respectively supplied to the first and second base units, wherein the voltage output signal is provided on one hand to a lamp and on the other hand via a capacitor and a reverse The diode is grounded, and a connection point between the capacitor and the diode is coupled to the supply end of the control unit. According to the invention, the connection point is also coupled to the measurement pin of the ΗΒ control unit, such that the ΗΒ control unit can measure the first and/or second BJ by measuring a steep slope of the voltage at the connection point. The actual cutoff signal. As described in relation to the above solution, the steep slope of the voltage is more accurately closer to the transient position of the voltage at the point than the voltage slope directly obtained at the original detection point ,, so that it can be more quickly and Accurately measure the actual cutoff signal of B JT . Also, the advantageous effects shown by the improvement of the above method can be obviously applied to the improvement of the electronic choke of the present invention to be described below. -10- 200850067 Preferably, the HB control unit is respectively displayed on the side of the control pulse for cutting off each of the first and second B]Ts and at the connection point. The first and second storage times of the first and second B T are obtained by the time between the corresponding steep slopes of the voltages. In this manner, the first and second storage times of the first and second BJTs can be detected more easily and accurately. In the electronic choke, the HB control unit compares the first and second storage times, and the shorter storage time is used to adjust the amplitude of the 1C output for base current adjustment. If the shorter storage time is less than a fixed 设定 set inside or outside 1C, 1C will increase the amplitude of the output pulse, and vice versa. In the electronic choke, the HB control unit compares the first and second storage times, and the longer storage time is used to adjust the dead time of the 1C output to ensure that there is often sufficient and appropriate dead time. The HB control unit can calculate and adjust the dead time according to the longer storage time of each cycle. For example, the HB control unit calculates and adjusts the dead time according to the formula of the dead time = ax long storage time + b, where a and b are fixed. In another case, the HB control unit may first maintain a fixed dead time, and then increase the dead time to d when the longer storage time exceeds a fixed threshold c, and if the longer storage time is less than the Fixing 値c reduces the stagnation time to the original 値. In the electronic choke, the connection point can be connected to the measurement pin MS of the HB control unit via a resistor. The control pulses of the ΗB control unit can be respectively connected to the 一一和弟一*Basic 兀' via a drive transformer to provide control pulses for alternately turning off the -11-200850067 one and the second BJTs. In another case, the control pulse of the HB control unit can be coupled to the first and second basic circuits via a semiconductor-based half-bridge driver, respectively, to provide for turning off the first and second BJTs. Control pulse. The invention will be described in detail with reference to the drawings. [Embodiment] FIG. 1 and Table 1 have been described in the background art and will not be elaborated. Reference is made to the electronic choke of the present invention shown in Fig. 2. The electronic 鎭 f current stream is mostly similar to the conventional art electronic choke shown in Fig. 1. However, the difference is that the measurement pin MS is connected to the connection point N between the capacitor C 2 and the diode D 1 via a resistor R3, and is used to measure the voltage signal at the connection point N, This signal is shown in Figure 3 as Ch4. It can be seen from the graph of Fig. 3 that the voltage VN (the voltage Ch4 at the connection point N) changes immediately at the starting point of the positive and negative slopes of the voltage VM (the voltage at the point ,), that is, The voltage V - Ν has a steep change from zero to positive (steep slope) and a steep change from positive to zero. The positive and negative slopes of this voltage V-M (the voltage at this point) are due to the cutoff of the BJT collector current. This characteristic indicates that the steep slope signal of voltage V - 可 can be used to detect the actual cutoff signal of the BJT, and thus the actual storage time of the BJT can be calculated by further comparing with the cutoff slope of the drive pulse. As shown in Figure 4, the cursor cursl is at the negative slope of the output pulse 〇UT1, and the cursor curs2 is at the negative slope of the voltage V-N (also at the negative slope of the upper BJT collector current). Thus, the time between cursl and curs2 is defined as the actual storage time T s 1 of the upper side B J T S 1 , and the actual storage time Tsl of the actual -12-200850067 is here 97 6.0-0.0 = 97 6.0 ns. Similarly, as shown in Fig. 5, the cursor ciirsl is at the negative slope of the output pulse OUT2, and the cursor curs2 is at the positive slope of the voltage VN (also at the lower side B) the negative slope of the T collector current Chi At). Therefore, the time between cursl and curs2 is defined as the actual storage time Ts2 of the lower side BIT S2, which is 1.016-0.0 = 1.16ps here. It can be seen that the actual storage time of the lower side BJT is greater than the actual storage time of the upper side B T, and Ts2-Tsl = 1.016 ps - 976.0 ns = 40.0 ns ... clearly, the connection point N is connected to the HB control unit The measurement pin MS causes the HB control unit to accurately measure the actual cutoff signal of the first and/or second Τ S1 and S2 by measuring the steep slope of the voltage at the connection point N. Furthermore, the HB control unit measures the side edges 〇1 and OUT2 of the control pulse on each of the first and second BJTs S1 and S2 on the one hand and the connection point N on the other hand. The first and second storage times Ts1 and Ts2 of the first and second BJTs S1 and S2 are obtained for the time between the corresponding steep slopes of the voltages thus occurring. In order for the two B Ji T s S 1 and S 2 to have appropriate driving currents regardless of the parameter tolerance, the HB control unit compares the first and second storage times, and the shorter storage time is used to adjust the base. The amplitude of the IC output for pole current adjustment. In this manner, the BJT with a shorter storage time is supplied with the appropriate current and maintains saturation during conduction. When another B&T with a longer storage time is turned on, it will saturate in a good conduction condition with minimal power loss, thus avoiding higher power loss of the BIT switch and flashing of the lamp. In particular, if the shorter storage time is less than a fixed chirp set within the 1C internal or external -13 - 200850067, the 1C will increase the amplitude of the output pulse accordingly, and vice versa. In order to avoid insufficient stagnant time caused by long storage time and thus ultimately damaging the two BJTs S 1 and S2 regardless of temperature changes, the HB control unit compares the first and second storage times, and the longer storage time Used to adjust the dead time of the 1C output to ensure that there is often enough and appropriate dead time. Specifically, the HB control unit calculates and adjusts the dead time according to a longer storage time of each cycle. In particular, the HB control unit 计算 r can calculate and adjust the dead time according to the formula of the dead time = ax storage time + b, where a and b are fixed 値. In another case, the HB control unit may first maintain a fixed dead time, then increase the dead time to d when the longer storage time exceeds a fixed threshold c, and if the longer storage time is less than the fixed time c, then reduce the stagnation time to the original 値. For the electronic choke of the present invention, the control pulse of the HB control unit can be respectively coupled to the first and second basic units via a driving transformer T1, so as to provide for turning off the first and second BJTs S1 and Control pulse of S2. Furthermore, the drive transformer T 1 can be replaced by a semiconductor-based half-bridge driver. From the above description it can be inferred that the present invention has provided an electronic choke that can be operated more safely and a method for operating the electronic choke. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a part of the circuit of the electronic choke of the prior art; FIG. 2 shows a part of the circuit of the electronic choke of the present invention; and FIG. 3 shows a curve of the voltage measured according to the present invention. Figure ·, -14-
200850067 第4圖顯示依據本發明在測量該上側β IT之 〇UT1的負斜率與在該連接點N上之負陡峭斜率 (亦即，該上側BJT之實際截止時間Tsl)時的曲縛 第5圖顯示依據本發明在測量該下側BJT之 OUT2的負斜率與在該連接點N上之正陡峭斜率 (亦即，該下側BJT之實際截止時間Ts2)時的曲糸I 表1顯示在一 BIT經歷溫度變化時在該習知技 出現之零電壓切換及非零電壓切換。 【主要元件符號說明】 ί. C1 〜C6 電容器 D1 二極體 L2 電感器 Μ 中心點 Ν 連接點 OUT1, OUT2 輸出 Rl，R3 〜R5 電阻器 S1 上側BJT S2 下側BJT Τ1 驅動變壓器 VCC 供應端 輸出脈衝 間之時間 :圖；以及 輸出脈衝 間之時間 [圖。 藝中可能 -15-200850067 FIG. 4 shows the fifth variation of the negative slope of 〇UT1 measured at the upper side β IT and the negative steep slope at the connection point N (ie, the actual cut-off time Tsl of the upper BJT) according to the present invention. The figure shows the curve I when measuring the negative slope of OUT2 of the lower side BJT and the positive steep slope at the connection point N (i.e., the actual cut-off time Ts2 of the lower side BJT) according to the present invention. A zero voltage switching and non-zero voltage switching occurring in the conventional technique when a BIT experiences a temperature change. [Main component symbol description] ί. C1 ~ C6 capacitor D1 diode L2 inductor Μ center point Ν connection point OUT1, OUT2 output Rl, R3 ~ R5 resistor S1 upper side BJT S2 lower side BJT Τ 1 drive transformer VCC supply output Time between pulses: graph; and time between output pulses [Figure. Art may -15-