M366856 五、新型說明： '【新型所屬之技術領域】 ' 本新型涉及一種多負載驅動系統，尤指一種應用於液晶電視 顯示器背光源模組的多燈管驅動系統。 【先前技術】 放電燈通常用作液晶顯不面板的背光源》由於該種燈管需要 .較高的驅動電壓才可以點亮，所以在大尺寸的電視液晶顯示面板 籲、中’不僅需要複數燈管提供足夠的亮度，而且在每個燈管兩端同 時載入交流高壓輸入訊號提供足夠的驅動電壓。然而在多燈管的 液晶顯示面板中，由於各燈管阻抗的差異’會使流經各並聯燈管 的電流分配不均勻。這不僅使某些燈管因電流過小而造成亮度不 足，影響整個液晶顯示面板的亮度均勻性，還會使得某些燈管因 電流過大而縮短燈管本身及整個液晶顯示面板的壽命。 習知的驅動複數燈管的電路，藉由控制載入在燈管兩端的變 ί 壓器使每一個燈管輸出電流相等。 圖1所不為典型的電感式多燈管均流平衡架構。多燈管驅動 系統400包括由複數平衡變壓器ι〇2所構成的環平衡器，其有利 .於在多燈背光系統中進行均流。平衡變壓器1〇2具各自的初級繞 、組和次級繞組，初級繞組與指定燈獨立地串聯連接，所有平^ 壓器102之次級繞組彼此串接形成—閉合迴路。由於次級繞組彼 此串接’故其傳導㈣流相同，㈣喊應的方式使各自的相級 繞組所傳導的電流相同，進而平衡各燈管顺之間的電流。此種 3 M366856 多燈官均辭衡架構’―個燈管需制—個變壓器，隨著燈管數 i的乓加蚤壓為數罝也相應增加，這樣必然會增大產品的體積， 增加產品的成本。 【新型内容】 有鑑於此，需提供一種多燈管驅動系統，不但可以使流經系 統中各燈管_電流制平衡，又可喊少變鞋的使用數量， .縮小產品體積，從而降低產品的成本。 ^ 一種多燈管驅動系統，用於驅動複數燈管組，包括換 流器電路，用於驅動該等燈管組；以及電流平衡電路，電 性連接至該換流器電路與該等燈管組之間，用於平衡各燈 管之間的電流。其中，該電流平衡電路包括複數變壓電路， 每一變壓電路由一個變壓器構成，該變壓器包括第一初級 繞組、第-次級繞組、第二初級繞組與第二次級繞組，該 第一初級繞組與第一次級繞組形成第一磁性迴路，該第二 1初級繞組與第二次級繞組形成第二磁性迴路。該等第一磁 性迴路之第-次級繞組相互串聯形成—閉合迴路，該閉合 迴路傳導公共電流，以平衡該等燈管虹之間的電流。該等 •第二磁性迴路分別連接該等燈管組，該等第二初級繞組與 、第二次級繞組具有相同的線圈臣數，分別電性連接至該燈 管組中的兩個燈管，用於平衡該等燈管組中兩個燈管之間 的電流。 本新型提供的多燈管驅動系統，通過在變壓器中設置 4 M366856 兩個磁性迴路，兩個燈管使用一個變壓器來達到各燈管之 -間的電流平衡，減少了變壓器的使用數量，從而縮小了產 - 品體積，降低了產品成本。 【實施方式】 參閱圖2，所示係本新型一較佳實施方式之多燈管驅動系統 200之電路結構示意圖。多燈管驅動系統2〇〇包括驅動電路1〇、 .升壓變壓器20、電流平衡電路30、燈管組40及反饋控制電路5〇。 Φ 驅動電路w連接至升壓變壓器2〇的初級側，兩者構成換流器電 路，用於接受直流訊號Vin的輸入，並將該直流訊號vin轉換為 可驅動燈管組40之父流訊號。本實施方式中，燈管組包括複 數燈管，分別藉由電流平衡電路30連接至換流器電路。為說明方 便，圖2中所示為四個燈管4021、4022、4041、4042，分別歸於 兩個燈管組402、404。電流平衡電路30電性連接至燈管組402、 404之高壓端，為說明之簡單起見，其包括第一變壓電路3〇2和第 籲 二變壓電路3〇4，分別連接至燈管組402、404。 第一變壓電路302包括第一磁性迴路3022和第二磁性迴路 3024。其中第一次磁性迴路3〇22包括初級繞組pil、次級繞組 S11 ’第二磁性迴路3024包括初級繞組pi2及次級繞組S12。其 中’初級繞組P12的輸入端與次級繞組S12的輸入端連接在一起 形成一公共端K1。初級繞組pii、pi2，次級繞組Sll、S12是卷 繞於同一磁心上，且初級繞組P12與次級繞組S12的線圈匝數相 等(請同時參閱圖4)。 5 M366856 同樣地’第二變壓電路3α4包括第三磁性迴路綱2和第四磁 J·生迴路3044。其中第二磁性迴路3〇42包括初級繞組奶、次級繞 -組S21 ’第四磁性迴路3〇44包括初級繞組p22及次級繞組奶。 其中’初級繞組P22的輸入端與次級繞组奶的輸入端連接在一 起幵/成λ K2。初級繞組p21、p22，次級繞組S21、S22是 卷、％於同磁〜上’且初級繞組p22與次級繞組奶的線圈阻數 相等。 本實把方式中第—變壓電路遞之第一磁性迴路弧2與第 二變壓電路304之第三雜迴路·之初級敝與次級繞組· 數比均相同。特別地，本實施方式中的第-變壓電路3〇2與第二 變壓電路3〇4均由-個變壓器構成，以減少變壓器的數量、節省 成本。 第變壓電路302之第—磁性迴路3〇22電性連接於升壓變壓 器20之次級輸出端與第二磁性迴路職之公共端κι之間，第二 磁性迴路麵電性連接至燈管組—的高壓端。其中，初級繞組 PH、人級繞組S12之輸出端分別電性連接至燈管組搬中 一燈管彻與第二辟術之高壓端。由於初級繞㈣ 級繞組S12的線·數相等，利用線·數比為1:1的磁性元“ 2一線_壓錢經電齡等的祕，而制平衡燈管 4021'4022的電流的目的。 同樣地，第二變壓電路3〇4之第三磁性迴路遞 升壓變壓器2〇之攻 电丨王$钱於 、’輪出端與第四磁性迴路3〇44之公共端幻 6 M366856 之間，第四磁性迴路綱4連接至燈管組顿之高壓端。財，初 級繞組P22與次級繞組奶之輸出端分別電性連接至燈管組 中的第-燈管魏與第二燈管撕2之高壓端。由於初級繞組p22 與次級繞組S22的線陳數相等。利用線_數比為1:1的磁性元 件必會使兩個賴的f壓及流、_流鱗的雜，崎到平衡燈 管4041，4042的電流的目的。 .第一變壓電路302之第-磁性迴路3022之初級繞組P11電性 連接至升賴魅20的魏輸出端與第二雖迴路遞的公共 端K1，第二變壓電路304之第三磁性迴路3〇42之初級繞組p21 電〖生連接至升壓變壓器20的次級輸出端與第四磁性迴路3〇44的 公共端Κ2，其次級繞組Sll ’ S21之輸入端與輸出端依次串聯連 接’形成一閉合迴路，傳導公共電流Ιχ。 本實施方式中’第一變壓電路302之第一磁性迴路3022與第 二變壓電路304之第三磁性迴路3042之初級繞組與次級繞組的匝 數比均相同，且次級繞組Sll，S21串聯所形成的閉合迴路傳导公 共電流Ιχ，因此，在感應效應下第一初級繞組PH、Ρ2ΐ傳導的電 流亦相同，流經燈管組402、404的公共電流II、12相同。由於流 經燈管組402中第一燈管4021與第二燈管4022的電流在繞組Ρ12 與S12的作用下相同，流經燈管組404中第〆燈管4041與第二燈 管4042的電流在繞組Ρ22與S22的作用下相同，因此，流經各個 燈管4021、4022、4041、4042的電流均相同，從而達到電流平衡 的目的。 7 M366856 本實施方式中，燈管組的數量為兩組，在其它實施方式中 -燈管組的數量可以為多於兩組，變壓⑽數量也相應增加。 •反饋控制電路50電性連接至第一磁性迴路302之次級㈣且 sii與第三磁性迴路之次級繞組S21形成的閉合迴路與驅動^路 1〇之間’以藉由該閉合迴路的反饋電流控制驅動電路1〇。反镇控 制電路50為脉寬調變控制器。 貝工 '參麵3,所示係本新型另-實施方式之多燈管驅動系統3〇〇 之電路結構示意圖。圖3的電路結構與電流平衡原理大致上與圖2 相同，不同之處在於’第一磁性迴路3〇22之初級繞組m電性串 接至第二磁性迴路3〇24之次級繞組S12與燈管4〇22之高壓端之 間，第三磁性迴路3042之初級繞組p21電性串接至第四磁性迴路 3044之次級繞組S22與燈管4〇42之高壓端之間。由於第二磁性迴 路3024之初級繞組p12與次級繞組S12的線圈匝數相等，在感應 效應下流經燈管4021、4022的電流相同。同樣地，第四磁性迴路 3044之初級繞組P22與次級繞組S22的線圈匝數相等，流經燈管 4041、4042的電流亦相同。又，第一變壓電路3〇2之第一磁性迴 路3022與第二變壓電路304之第三磁性迴路3042之初級繞組與 次級繞組的匝數比均相同，且次級繞組Sll，S21串聯所形成的閉 合迴路傳导公共電流Iy，因此，在感應效應下初級繞組Pll、P21 傳導的電流相同。燈管4022、4042分別串接初級繞組Pll、P21， 因此’流經燈管4022、4042之電流亦相同，又流經燈管4021、4022 的電流相同，流經燈管4041、4042的電流相同，由此可以得知， 8 M366856 流經各個燈管4021、4022、4041、4042的電流均相同，進而達到 ' 電流平衡的目的。 请參閱圖4’所示為圖2中多燈管驅動系統200中變壓電路之 結構示意圖。前已述及，本實施方式中第一變壓電路3〇2與第二 變壓電路304均由一個變壓器構成，換言之’第一變壓電路3〇2 即是第一變壓器302’第二變壓電路304即是第二變壓器304。以 ‘第一變壓器302為例，變壓器302包括磁心602、繞線架604，初 # 級繞組Pll、P12及次級繞組Sll、S12。本實施方式中，磁心是 由兩個E型鐵心對接形成，在其它實施方式中，磁心也可為扭型 鐵心。繞線架604包括四個線槽6041、6042、6043、6044，分別 纏繞次級繞組sii、初級繞組P11、次級繞組S12、初級繞組pi2。 磁心602穿過繞線架6〇4’初級繞組P11與次級繞組S11形成第一 磁性迴路3022 ’初級繞組P12及次級繞組S12形成第二磁性迴路 3024。各繞組的連接方式請參閱圖2。 上所述’本新型之多燈管驅㈣統，通過在-個變壓器上 設置兩個雜娜’兩健管伽—㈣職就可以達到各燈管 之間的電流平衡，有效的縮小了產品體積，節省了成本。 _ 本新型雖以較佳實施例揭露如上，然其並非用以限定本新 .型。惟，任何熟悉此項技藝者，在不脫離本新型之精神和範圍内， 當可做稍許更输_，耻本新型之倾範圍#視後附之申請 專利範圍所界定者為準。 【圖式簡單說明】 9 M366856 l的知電感^^燈管均流平衡架構電路圖。 ^係本新型一較佳實施方式多燈管驅動系統電路結構示意 圖3係本新型另一實施方式多燈管驅動系統電路結構示意圖。 圖4係圖2所示變壓器的結構示意圖。 【主要元件符號說明】M366856 V. New description: '[New technology field] ' This new type relates to a multi-load drive system, especially a multi-lamp drive system for LCD TV display backlight module. [Prior Art] The discharge lamp is usually used as a backlight for a liquid crystal display panel. Because this type of lamp requires a higher driving voltage, it can be lit. Therefore, in a large-sized TV liquid crystal display panel, it is not only required to be plural. The lamp provides sufficient brightness and an AC high voltage input signal is simultaneously applied across each tube to provide sufficient drive voltage. However, in a multi-lamp liquid crystal display panel, the current flowing through each of the parallel lamps is unevenly distributed due to the difference in the impedance of the respective lamps. This not only causes some lamps to have insufficient brightness due to excessive current, affects the brightness uniformity of the entire liquid crystal display panel, and also causes some lamps to shorten the life of the lamp itself and the entire liquid crystal display panel due to excessive current. A conventional circuit for driving a plurality of lamps controls the output current of each of the lamps to be equal by controlling a transformer loaded at both ends of the lamp. Figure 1 is not a typical inductive multi-lamp current sharing architecture. The multi-lamp drive system 400 includes a ring balancer comprised of a plurality of balance transformers ι 2 that facilitates current sharing in a multi-lamp backlight system. The balance transformers 1 2 have respective primary windings, groups and secondary windings, the primary windings being connected in series with the designated lamps, and the secondary windings of all of the voltage regulators 102 are connected in series to each other to form a closed loop. Since the secondary windings are connected in series with each other, the conduction (four) flow is the same, and (4) the currents conducted by the respective phase windings are the same, thereby balancing the current between the lamps. This kind of 3 M366856 multi-light official balance system '------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- the cost of. [New content] In view of this, it is necessary to provide a multi-lamp driving system, which not only can balance the currents flowing through the lamps in the system, but also can reduce the number of shoes used, and reduce the volume of the product, thereby reducing the product. the cost of. ^ A multi-lamp driving system for driving a plurality of lamp groups, including an inverter circuit for driving the lamp groups; and a current balancing circuit electrically connected to the converter circuit and the lamps Between groups, used to balance the current between the lamps. Wherein, the current balancing circuit comprises a plurality of transformer circuits, each transformer is configured by a transformer, the transformer comprising a first primary winding, a first secondary winding, a second primary winding and a second secondary winding, the first The primary winding forms a first magnetic circuit with the first secondary winding, and the second primary winding and the second secondary winding form a second magnetic circuit. The first and secondary windings of the first magnetic circuit are formed in series with each other in a closed loop that conducts a common current to balance the current between the tubes. The second magnetic circuits are respectively connected to the tube groups, and the second primary windings and the second secondary windings have the same number of coils, and are electrically connected to the two tubes in the tube group respectively. For balancing the current between the two tubes in the tube group. The multi-lamp driving system provided by the present invention has two magnetic circuits of 4 M366856 in the transformer, and two lamps use a transformer to achieve current balance between the lamps, thereby reducing the number of transformers used, thereby reducing the number of transformers. Production - product volume, reducing product costs. [Embodiment] Referring to Figure 2, there is shown a circuit diagram of a multi-lamp driving system 200 of a preferred embodiment of the present invention. The multi-lamp driving system 2 includes a driving circuit 1 , a step-up transformer 20 , a current balancing circuit 30 , a lamp group 40 , and a feedback control circuit 5 . The Φ driving circuit w is connected to the primary side of the step-up transformer 2A, and the two constitute an inverter circuit for receiving the input of the DC signal Vin, and converting the DC signal vin into a parental signal capable of driving the lamp group 40 . In this embodiment, the lamp group includes a plurality of lamps connected to the inverter circuit by a current balancing circuit 30, respectively. For convenience of explanation, four lamps 4021, 4022, 4041, and 4042 are shown in Fig. 2, which are attributed to the two lamp groups 402, 404, respectively. The current balancing circuit 30 is electrically connected to the high voltage terminals of the lamp sets 402, 404. For simplicity of description, it includes a first transformer circuit 3〇2 and a second transformer circuit 3〇4, respectively connected to the lamp. Tube sets 402, 404. The first transformer circuit 302 includes a first magnetic circuit 3022 and a second magnetic circuit 3024. The first magnetic circuit 3〇22 includes a primary winding pil, a secondary winding S11', and a second magnetic circuit 3024 includes a primary winding pi2 and a secondary winding S12. The input of the 'primary winding P12' is connected to the input of the secondary winding S12 to form a common terminal K1. The primary windings pii, pi2, the secondary windings S11, S12 are wound on the same core, and the number of turns of the primary winding P12 and the secondary winding S12 are equal (see also Figure 4). 5 M366856 Similarly, the second transformer circuit 3α4 includes a third magnetic circuit class 2 and a fourth magnetic circuit. The second magnetic circuit 3〇42 includes primary winding milk, and the secondary winding-group S21' fourth magnetic circuit 3〇44 includes a primary winding p22 and a secondary winding milk. Wherein the input of the primary winding P22 is connected to the input of the secondary winding milk in a 幵 K / λ K2. The primary windings p21, p22, the secondary windings S21, S22 are wound, % is in the same magnetic flux ~ upper and the primary winding p22 and the secondary winding milk have the same number of coil resistances. In the present embodiment, the first magnetic circuit arc 2 of the first transformer circuit and the third circuit of the second transformer circuit 304 have the same primary winding and secondary winding ratio. In particular, the first transformer circuit 3〇2 and the second transformer circuit 3〇4 in the present embodiment are each constituted by one transformer to reduce the number of transformers and to save cost. The first magnetic circuit 3〇22 of the first transformer circuit 302 is electrically connected between the secondary output end of the step-up transformer 20 and the common terminal κι of the second magnetic circuit, and the second magnetic circuit is electrically connected to the lamp. Group - the high end. Wherein, the output ends of the primary winding PH and the human-level winding S12 are electrically connected to the lamp tube group and the high-voltage end of the second lamp. Since the number of lines of the primary winding (four) winding S12 is equal, the purpose of balancing the current of the lamp 4021'4022 is to use a magnetic element having a line-to-number ratio of 1:1 "2 line _ press money and electricity age". Similarly, the third magnetic circuit of the second transformer circuit 3〇4 is boosted by the transformer 2, and the common end of the 'round and the fourth magnetic circuit 3〇44 is 6 M366856. Between the fourth magnetic circuit class 4 is connected to the high voltage end of the lamp tube group. The output terminals of the primary winding P22 and the secondary winding milk are electrically connected to the first lamp tube and the second in the lamp tube group respectively. The lamp tube tears the high voltage end of the tube 2. Since the number of lines of the primary winding p22 and the secondary winding S22 is equal, the magnetic element using the line _number ratio of 1:1 will cause the two pressures and flow, _ flow scale The purpose of the current is to balance the current of the lamp 4041, 4042. The primary winding P11 of the first magnetic circuit 3022 of the first transformer circuit 302 is electrically connected to the Wei output of the booster 20 and the second circuit. The first common winding p21 of the third magnetic circuit 3〇42 of the second transformer circuit 304 is electrically connected to the step-up transformer 20 The output terminal and the common terminal 第四2 of the fourth magnetic circuit 3〇44, the input end and the output end of the secondary winding S11′S21 are sequentially connected in series to form a closed loop, and conduct a common current Ιχ. In the present embodiment, the first change The first magnetic circuit 3022 of the voltage circuit 302 and the third magnetic circuit 3042 of the second transformer circuit 304 have the same turns ratio of the primary winding and the secondary winding, and the closed loop of the secondary winding S11, S21 is connected in series. The common current is induced, so that the current conducted by the first primary windings PH, Ρ2ΐ is also the same under the inductive effect, and the common currents II, 12 flowing through the lamp sets 402, 404 are the same. The current of the lamp tube 4021 and the second lamp tube 4022 is the same under the action of the winding turns 12 and S12, and the current flowing through the second lamp tube 4041 and the second lamp tube 4042 in the lamp tube group 404 is the same under the action of the winding turns 22 and S22. Therefore, the currents flowing through the respective lamps 4021, 4022, 4041, and 4042 are the same, thereby achieving the purpose of current balancing. 7 M366856 In this embodiment, the number of the lamp groups is two groups, and in other embodiments, the lamps Management group The number can be more than two groups, and the number of transformers (10) is also increased accordingly. • The feedback control circuit 50 is electrically connected to the secondary (four) of the first magnetic circuit 302 and the closed loop formed by the sii and the secondary winding S21 of the third magnetic circuit The drive circuit 1 is controlled by the feedback current of the closed loop. The inverse control circuit 50 is a pulse width modulation controller. The Beacon's face 3 is shown as a new type. - Schematic diagram of the circuit structure of the multi-lamp driving system of the embodiment. The circuit structure and current balance principle of FIG. 3 is substantially the same as that of FIG. 2, except that the primary winding of the first magnetic circuit 3〇22 is electrically Between the secondary winding S12 of the second magnetic circuit 3〇24 and the high voltage end of the lamp tube 4〇22, the primary winding p21 of the third magnetic circuit 3042 is electrically connected in series to the secondary of the fourth magnetic circuit 3044. The winding S22 is between the high voltage end of the lamp tube 4〇42. Since the number of turns of the primary winding p12 of the second magnetic circuit 3024 and the secondary winding S12 are equal, the current flowing through the lamps 4021, 4022 is the same under the inductive effect. Similarly, the primary winding P22 of the fourth magnetic circuit 3044 has the same number of turns of the coil as the secondary winding S22, and the current flowing through the lamps 4041, 4042 is also the same. Moreover, the turns ratio of the primary winding and the secondary winding of the first magnetic circuit 3022 of the first transformer circuit 3〇2 and the third magnetic circuit 3042 of the second transformer circuit 304 are the same, and the secondary windings S11, S21 The closed loop formed in series conducts the common current Iy, and therefore, the primary windings P11, P21 conduct the same current under the inductive effect. The lamps 4022 and 4042 are connected in series with the primary windings P11 and P21, respectively. Therefore, the current flowing through the lamps 4022 and 4042 is the same, and the current flowing through the lamps 4021 and 4022 is the same, and the current flowing through the lamps 4041 and 4042 is the same. Therefore, it can be known that 8 M366856 flows through the respective lamps 4021, 4022, 4041, and 4042, and the current balance is achieved. Please refer to FIG. 4' for a structural diagram of a transformer circuit in the multi-lamp driving system 200 of FIG. As described above, in the present embodiment, the first transformer circuit 3〇2 and the second transformer circuit 304 are both constituted by one transformer. In other words, the first transformer circuit 3〇2 is the second transformer 302′. The voltage circuit 304 is the second transformer 304. Taking the first transformer 302 as an example, the transformer 302 includes a core 602, a bobbin 604, initial stage windings P11 and P12, and secondary windings S11 and S12. In the present embodiment, the core is formed by butting two E-cores. In other embodiments, the core may be a torsion core. The bobbin 604 includes four slots 6041, 6042, 6043, 6044 wound with a secondary winding sii, a primary winding P11, a secondary winding S12, and a primary winding pi2, respectively. The core 602 passes through the bobbin 6〇4' primary winding P11 and the secondary winding S11 to form a first magnetic circuit 3022' primary winding P12 and secondary winding S12 forming a second magnetic circuit 3024. See Figure 2 for the connection of each winding. The above-mentioned multi-lamp (four) system of the new type can achieve the current balance between the lamps by setting two Zaina's two-tube gamma-(four) positions on one transformer, effectively reducing the product. Volume, saving costs. The present invention is disclosed above in the preferred embodiment, but it is not intended to limit the present invention. However, anyone who is familiar with this skill can do a little more loss without departing from the spirit and scope of the present invention. [Simple description of the diagram] 9 M366856 l knows the inductance ^^ lamp flow equalization architecture circuit diagram. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 3 is a schematic view showing the circuit structure of a multi-lamp driving system according to another embodiment of the present invention. Figure 4 is a schematic view showing the structure of the transformer shown in Figure 2. [Main component symbol description]
驅動電路 10 電壓源 100 燈管組 104、402、404、40 平衡變壓器 102 升壓變壓器 20 多燈管驅動系統 200、300、400 電流平衡電路 30 變壓電路 302、304 磁性迴路 3022、3024、3042、3044 燈管 4021 、 4022 、 4041 、 4042 反饋控制電路 50 鐵心 602 繞線架 604 線槽 6041、6042、6043、6044 初級繞組 Pll、Ρ12、Ρ21、Ρ22 次級繞組 Sll、S12、S21、S22 M366856 公共電流 Ιχ、 電流 11 ' 公共端 Κ1 iy 12 、K2Drive circuit 10 voltage source 100 lamp group 104, 402, 404, 40 balance transformer 102 step-up transformer 20 multi-lamp drive system 200, 300, 400 current balancing circuit 30 transformer circuit 302, 304 magnetic circuit 3022, 3024, 3042 3044 Light tube 4021, 4022, 4041, 4042 Feedback control circuit 50 Core 602 Winding frame 604 Trunking 6041, 6042, 6043, 6044 Primary winding P11, Ρ12, Ρ21, Ρ22 Secondary winding S11, S12, S21, S22 M366856 Common current Ιχ, current 11 'Common terminal Κ1 iy 12, K2
1111