TWI432097B - Double-lamp driving circuit - Google Patents
Double-lamp driving circuit Download PDFInfo
- Publication number
- TWI432097B TWI432097B TW98106381A TW98106381A TWI432097B TW I432097 B TWI432097 B TW I432097B TW 98106381 A TW98106381 A TW 98106381A TW 98106381 A TW98106381 A TW 98106381A TW I432097 B TWI432097 B TW I432097B
- Authority
- TW
- Taiwan
- Prior art keywords
- circuit
- frequency switching
- signal
- resistor
- output
- Prior art date
Links
Description
本發明涉及燈管驅動裝置，尤其係關於一種用於液晶顯示器(Liquid Crystal Display，LCD)雙燈管之驅動裝置。 The invention relates to a lamp driving device, in particular to a driving device for a liquid crystal display (LCD) double lamp.
在較小型之液晶顯示(Liquid Crystal Display，LCD)面板中，一般設置兩個燈管即可提供足夠的亮度，該兩個燈管係由換流器電路(Inverter Circuit)來驅動，其可供應交流訊號至燈管。 In a smaller liquid crystal display (LCD) panel, two lamps are generally provided to provide sufficient brightness. The two lamps are driven by an inverter circuit, which can be supplied. Exchange signal to the lamp.
換流器電路中常常以共用同一脈寬調變(pulse-width modulation,PWM)控制器或者獨立選用兩個PWM控制器組合同步線路進行兩個燈管的同步驅動控制，因此兩個燈管僅可以同步驅動或關斷，存在可調光範圍與光、電效率的限制。 In the inverter circuit, the synchronous drive control of the two lamps is often performed by sharing the same pulse-width modulation (PWM) controller or independently selecting two PWM controllers to synchronize the lines, so the two lamps are only It can be driven or turned off synchronously, and there is a limitation of the dimmable range and the optical and electrical efficiency.
有鑑於此，需提供一種雙燈管驅動電路，可異步驅動雙燈管，從而使可調光範圍廣，且改善光、電效率。 In view of this, it is necessary to provide a dual lamp driving circuit that can asynchronously drive the two lamps, thereby making the dimming range wide and improving the light and electric efficiency.
一種雙燈管驅動電路，用於驅動第一燈管與第二燈管，包括第一頻率切換控制電路、第二頻率切換控制電路、頻率切換設置電路、第一電源轉換電路、第二電源轉換電路、第一變壓電路、第二變壓電路及迴授電路。第一頻率切換控制電路用於接收第一致能訊號，並根據第一致能訊號輸出第一頻率切換訊號。第二頻率切 換控制電路用於接收第二致能訊號，並根據第二致能訊號輸出第二頻率切換訊號。頻率切換設置電路用於根據第一頻率切換訊號及第二頻率切換訊號調整輸出不同的輸出脈寬調變(pulse-width modulation,PWM)控制訊號。第一電源轉換電路連接於頻率切換設置電路，用於根據頻率切換設置電路輸出的PWM控制訊號，將外部電訊號轉換為第一方波訊號輸出。第二電源轉換電路連接於頻率切換設置電路，受控於第二致能訊號，以接收頻率切換設置電路輸出的PWM控制訊號，將外部電訊號轉換為第二方波訊號輸出。第一變壓電路連接於第一電源轉換電路與第一燈管之間，用於將第一方波訊號升壓整流後輸出可驅動第一燈管之第一弦波交流訊號。第二變壓電路連接於第二電源轉換電路與第二燈管之間，用於將第二方波訊號升壓整流後輸出可驅動第二燈管之第二弦波交流訊號。迴授電路連接於該等燈管與該等頻率切換控制電路之間，用於將流經第一燈管的第一電流訊號迴授至第一頻率切換控制電路以及將流經第二燈管的第二電流訊號迴授至第二頻率切換控制電路，以控制第一頻率切換控制電路與第二頻率切換控制電路的輸出。 A dual lamp driving circuit for driving a first lamp tube and a second lamp tube, comprising a first frequency switching control circuit, a second frequency switching control circuit, a frequency switching setting circuit, a first power conversion circuit, and a second power conversion The circuit, the first transformer circuit, the second transformer circuit, and the feedback circuit. The first frequency switching control circuit is configured to receive the first enable signal and output the first frequency switching signal according to the first enable signal. Second frequency cut The switching control circuit is configured to receive the second enable signal and output the second frequency switching signal according to the second enable signal. The frequency switching setting circuit is configured to adjust and output different output pulse width modulation (PWM) control signals according to the first frequency switching signal and the second frequency switching signal. The first power conversion circuit is connected to the frequency switching setting circuit for converting the external electrical signal into the first square wave signal output according to the PWM control signal output by the frequency switching setting circuit. The second power conversion circuit is connected to the frequency switching setting circuit, and is controlled by the second enable signal to receive the PWM control signal output by the frequency switching setting circuit, and convert the external electrical signal into the second square wave signal output. The first transformer circuit is connected between the first power conversion circuit and the first lamp tube for boosting and rectifying the first square wave signal to output a first sine wave alternating current signal that can drive the first lamp. The second transformer circuit is connected between the second power conversion circuit and the second lamp tube for boosting and rectifying the second square wave signal to output a second sine wave alternating current signal that can drive the second lamp. a feedback circuit is connected between the lamps and the frequency switching control circuit for feeding back a first current signal flowing through the first lamp to the first frequency switching control circuit and flowing through the second lamp The second current signal is fed back to the second frequency switching control circuit to control the outputs of the first frequency switching control circuit and the second frequency switching control circuit.
藉由以下對具體實施方式之詳細描述結合附圖，將可輕易瞭解上述內容及此項發明之諸多優點。 The above and many of the advantages of the invention will be readily apparent from the Detailed Description of the Detailed Description.
11‧‧‧第一燈管 11‧‧‧First lamp
12‧‧‧第二燈管 12‧‧‧Second light tube
20‧‧‧變壓電路 20‧‧‧Transformer circuit
30‧‧‧電源轉換電路 30‧‧‧Power conversion circuit
40‧‧‧頻率切換設置電路 40‧‧‧Frequency switching setting circuit
41‧‧‧PWM控制器 41‧‧‧PWM controller
411‧‧‧燈管時鐘震盪器 411‧‧‧Lamp Clock Oscillator
412‧‧‧控制邏輯單元 412‧‧‧Control logic unit
50‧‧‧頻率切換控制電路 50‧‧‧frequency switching control circuit
51‧‧‧第一頻率切換控制電路 51‧‧‧First frequency switching control circuit
511‧‧‧第一充電電路 511‧‧‧First charging circuit
512‧‧‧第一開關電路 512‧‧‧First switch circuit
52‧‧‧第二頻率切換控制電路 52‧‧‧Second frequency switching control circuit
521‧‧‧第二充電電路 521‧‧‧Second charging circuit
522‧‧‧第二開關電路 522‧‧‧Second switch circuit
60‧‧‧迴授電路 60‧‧‧Return circuit
70‧‧‧連接電路 70‧‧‧Connected circuit
R1‧‧‧第一電阻 R1‧‧‧first resistance
R2‧‧‧第二電阻 R2‧‧‧second resistance
R3‧‧‧第三電阻 R3‧‧‧ third resistor
R4‧‧‧第四電阻 R4‧‧‧fourth resistor
R5‧‧‧第五電阻 R5‧‧‧ fifth resistor
R6‧‧‧第六電阻 R6‧‧‧ sixth resistor
R7‧‧‧第七電阻 R7‧‧‧ seventh resistor
C1‧‧‧第一電容 C1‧‧‧first capacitor
C2‧‧‧第二電容 C2‧‧‧second capacitor
C3‧‧‧第三電容 C3‧‧‧ third capacitor
C4‧‧‧第四電容 C4‧‧‧fourth capacitor
Q1‧‧‧第一電晶體 Q1‧‧‧First transistor
Q2‧‧‧第二電晶體 Q2‧‧‧Second transistor
Q3‧‧‧第三電晶體 Q3‧‧‧ Third transistor
D1‧‧‧第一二極體 D1‧‧‧First Diode
D2‧‧‧第二二極體 D2‧‧‧ second diode
圖1係本發明之雙燈管驅動電路之示意圖。 1 is a schematic view of a dual lamp driving circuit of the present invention.
圖2係本發明之頻率切換控制電路與頻率切換設置電路之細化電路圖。 2 is a detailed circuit diagram of the frequency switching control circuit and the frequency switching setting circuit of the present invention.
圖3係本發明之以工作模式成功驅動第二燈管之示意圖。 Figure 3 is a schematic illustration of the successful operation of the second lamp in the operating mode of the present invention.
圖4係本發明之未能以工作模式驅動第二燈管而啟動點燈模式驅動第二燈管之示意圖。 4 is a schematic diagram of the present invention in which the second lamp is not driven in the operating mode and the lighting mode is activated in the lighting mode.
圖1係本發明雙燈管驅動電路之示意圖。本發明之雙燈管驅動電路用於驅動第一燈管11與第二燈管12，包括變壓電路20、電源轉換電路30、頻率切換設置電路40及頻率切換控制電路50。其中，電源轉換電路30用於將外部提供的電訊號轉換為方波訊號，變壓電路20則將該方波訊號升壓整流後輸出可驅動該等燈管11與12之弦波交流訊號。頻率切換設置電路40及頻率切換控制電路50共同作用，以控制電源轉換電路30以不同時脈輸出該方波訊號，從而異步點亮該等燈管11、12。 1 is a schematic view of a dual lamp driving circuit of the present invention. The dual lamp driving circuit of the present invention is used for driving the first lamp tube 11 and the second lamp tube 12, and includes a transformer circuit 20, a power conversion circuit 30, a frequency switching setting circuit 40, and a frequency switching control circuit 50. The power conversion circuit 30 is configured to convert the externally supplied electrical signal into a square wave signal, and the voltage transformation circuit 20 boosts and rectifies the square wave signal to output a sine wave alternating signal that can drive the lamps 11 and 12. The frequency switching setting circuit 40 and the frequency switching control circuit 50 cooperate to control the power conversion circuit 30 to output the square wave signal at different clocks, thereby asynchronously lighting the lamps 11, 12.
頻率切換控制電路50用於接收第一致能訊號與第二致能訊號，並輸出第一頻率切換訊號與第二頻率切換訊號。第一致能訊號與第二致能訊號為非同步訊號。 The frequency switching control circuit 50 is configured to receive the first enable signal and the second enable signal, and output the first frequency switching signal and the second frequency switching signal. The first consistent signal and the second enable signal are asynchronous signals.
在本實施方式中，頻率切換控制電路50包括第一頻率切換控制電路51與第二頻率切換控制電路52。第一頻率切換控制電路51用於接收該第一致能訊號，並根據該第一致能訊號輸出第一頻率切換訊號。第二頻率切換控制電路52用於接收第二致能訊號，並根據第二致能訊號輸出第二頻率切換訊號。 In the present embodiment, the frequency switching control circuit 50 includes a first frequency switching control circuit 51 and a second frequency switching control circuit 52. The first frequency switching control circuit 51 is configured to receive the first enabling signal, and output a first frequency switching signal according to the first enabling signal. The second frequency switching control circuit 52 is configured to receive the second enable signal and output the second frequency switching signal according to the second enable signal.
頻率切換設置電路40與第一頻率切換控制電路51及第二頻率切換控制電路52相連接，用於根據第一頻率切換訊號及第二頻率切換訊號調整輸出不同的PWM控制訊號。 The frequency switching setting circuit 40 is connected to the first frequency switching control circuit 51 and the second frequency switching control circuit 52 for adjusting different PWM control signals according to the first frequency switching signal and the second frequency switching signal.
在本實施方式中，頻率切換設置電路40包括脈寬調變( pulse-width modulation,PWM)控制器41，用於產生PWM控制訊號。 In the present embodiment, the frequency switching setting circuit 40 includes pulse width modulation ( A pulse-width modulation (PWM) controller 41 is configured to generate a PWM control signal.
電源轉換電路30包括第一電源轉換電路31與第二電源轉換電路32。 The power conversion circuit 30 includes a first power conversion circuit 31 and a second power conversion circuit 32.
在本實施方式中，第一電源轉換電路31連接於頻率切換設置電路40，用於將外部提供的電訊號轉換為第一方波訊號輸出。在本發明另一實施方式中，第一電源轉換電路31受控於第一致能訊號，用以選擇第一電源轉換電路31是否接收頻率切換設置電路40輸出的PWM控制訊號，若接收到第一致能訊號，則第一電源轉換電路31接收頻率切換控制電路40輸出的PWM控制訊號以輸出第一方波訊號。若沒有接收到第一致能訊號，則第一電源轉換電路31不接收頻率切換控制電路40輸出的PWM控制訊號，亦不輸出第一方波訊號。在本實施方式中，第一致能訊號為持續的訊號。 In the present embodiment, the first power conversion circuit 31 is connected to the frequency switching setting circuit 40 for converting the externally supplied electrical signal into the first square wave signal output. In another embodiment of the present invention, the first power conversion circuit 31 is controlled by the first enable signal for selecting whether the first power conversion circuit 31 receives the PWM control signal output by the frequency switching setting circuit 40. The first power conversion circuit 31 receives the PWM control signal output by the frequency switching control circuit 40 to output the first square wave signal. If the first enable signal is not received, the first power conversion circuit 31 does not receive the PWM control signal output by the frequency switching control circuit 40, nor does it output the first square wave signal. In this embodiment, the first enable signal is a continuous signal.
第二電源轉換電路32連接於頻率切換設置電路40，用於根據頻率切換設置電路40輸出的PWM控制訊號，將外部提供的電訊號轉換為第二方波訊號輸出。在本實施方式中，控制第二電源轉換電路32受控於第二致能訊號，用以選擇控制第二電源轉換電路32是否接收PWM控制訊號，若接收到第二致能訊號，則第二電源轉換電路32接收頻率切換控制電路40輸出的PWM控制訊號以輸出第二方波訊號。若沒有接收到第二致能訊號，則第二電源轉換電路32不接收頻率切換控制電路40輸出的PWM控制訊號，亦不輸出第二方波訊號。在本實施方式中，第二致能訊號為持續的訊號。 The second power conversion circuit 32 is connected to the frequency switching setting circuit 40 for converting the externally supplied electrical signal into the second square wave signal output according to the PWM control signal output by the frequency switching setting circuit 40. In this embodiment, the second power conversion circuit 32 is controlled to be controlled by the second enable signal for selectively controlling whether the second power conversion circuit 32 receives the PWM control signal, and if the second enable signal is received, the second The power conversion circuit 32 receives the PWM control signal output by the frequency switching control circuit 40 to output a second square wave signal. If the second enable signal is not received, the second power conversion circuit 32 does not receive the PWM control signal output by the frequency switching control circuit 40, nor does it output the second square wave signal. In this embodiment, the second enable signal is a continuous signal.
變壓電路20包括第一變壓電路21與第二變壓電路22。第一變壓電路21連接於第一電源轉換電路31與第一燈管11之間，用於將第一 方波訊號升壓整流後輸出可驅動第一燈管11之第一弦波交流訊號。第二變壓電路22連接於第二電源轉換電路32與第二燈管12之間，用於將第二交流訊號升壓整流後輸出可驅動第二燈管12之第二弦波交流訊號。 The transformer circuit 20 includes a first transformer circuit 21 and a second transformer circuit 22. The first transformer circuit 21 is connected between the first power conversion circuit 31 and the first lamp tube 11 for The square wave signal boost rectifier output can drive the first sine wave AC signal of the first lamp 11. The second transformer circuit 22 is connected between the second power conversion circuit 32 and the second lamp 12 for boosting and rectifying the second AC signal to output a second sine wave AC signal that can drive the second lamp 12.
迴授電路60連接於該等燈管11、12與頻率切換控制電路50之間，用於將流經第一燈管11的第一電流訊號迴授至第一頻率切換控制電路51以及流經第二燈管12的第二電流訊號迴授至第二頻率切換控制電路52，以控制第一頻率切換控制電路51與第二頻率切換控制電路52的輸出。 The feedback circuit 60 is connected between the lamps 11 and 12 and the frequency switching control circuit 50 for feeding back the first current signal flowing through the first lamp 11 to the first frequency switching control circuit 51 and flowing through The second current signal of the second tube 12 is fed back to the second frequency switching control circuit 52 to control the outputs of the first frequency switching control circuit 51 and the second frequency switching control circuit 52.
圖2係本發明之頻率切換控制電路50與頻率切換設置電路40之細化電路圖。 2 is a detailed circuit diagram of the frequency switching control circuit 50 and the frequency switching setting circuit 40 of the present invention.
在本實施方式中，第一頻率切換控制電路51包括第一充電電路511與第一開關電路512。第一充電電路511接收第一致能訊號，並根據第一致能訊號輸出第一頻率切換訊號。第一開關電路512接收迴授電路60迴授之流經第一燈管11的第一電流訊號，並在收到第一電流訊號後短路第一充電電路511之輸出。 In the present embodiment, the first frequency switching control circuit 51 includes a first charging circuit 511 and a first switching circuit 512. The first charging circuit 511 receives the first enable signal and outputs a first frequency switching signal according to the first enable signal. The first switch circuit 512 receives the first current signal flowing back through the first lamp 11 fed back by the feedback circuit 60, and shorts the output of the first charging circuit 511 after receiving the first current signal.
在本實施方式中，第一充電電路511包括第一電阻R1與第一電容C1。第一電阻R1一端接收第一致能訊號，其阻值較小，用於限流。第一電容C1一端連接於第一電阻R1之另一端，第一電容C1另一端接地。當第一充電電路511接收到第一致能訊號後，經過第一電阻R1對第一電容C1進行充電，並於第一電阻R1與第一電容C1之交接點輸出第一頻率切換訊號。 In the embodiment, the first charging circuit 511 includes a first resistor R1 and a first capacitor C1. The first resistor R1 receives the first enable signal at one end, and has a small resistance value for current limiting. One end of the first capacitor C1 is connected to the other end of the first resistor R1, and the other end of the first capacitor C1 is grounded. After receiving the first enable signal, the first charging circuit 511 charges the first capacitor C1 through the first resistor R1, and outputs a first frequency switching signal at the intersection of the first resistor R1 and the first capacitor C1.
第一開關電路512包括第二電阻R2與第一電晶體Q1，第二電阻R2 一端接收迴授電路60所迴授之第一電流訊號，用於限流。在本實施方式中，第一電晶體Q1的基極連接於第二電阻R2之另一端，其汲極連接於第一電阻R1與第一電容C1的交接點，其射極接地。當第一開關電路512藉由第二電阻R2接收到第一電流訊號後，第一電晶體Q1之基極電壓升高，使得第一電晶體Q1導通，將第一充電電路511之輸出經過第一電晶體Q1之汲極接地，則第一充電電路511停止向頻率切換設置電路40輸出第一頻率切換訊號。 The first switch circuit 512 includes a second resistor R2 and a first transistor Q1, and a second resistor R2 One end receives the first current signal fed back by the feedback circuit 60 for current limiting. In this embodiment, the base of the first transistor Q1 is connected to the other end of the second resistor R2, and the drain is connected to the junction of the first resistor R1 and the first capacitor C1, and the emitter is grounded. After the first switching circuit 512 receives the first current signal through the second resistor R2, the base voltage of the first transistor Q1 rises, so that the first transistor Q1 is turned on, and the output of the first charging circuit 511 passes through the first When the drain of a transistor Q1 is grounded, the first charging circuit 511 stops outputting the first frequency switching signal to the frequency switching setting circuit 40.
作為本發明一實施例之進一步改進，第一開關電路512更包括第二電容C2，其一端連接於第二電阻R2的一端，其另一端接地，用於對第一電流訊號進行濾波。 As a further improvement of an embodiment of the present invention, the first switch circuit 512 further includes a second capacitor C2, one end of which is connected to one end of the second resistor R2, and the other end of which is grounded for filtering the first current signal.
第二頻率控制電路52包括第二充電電路521與第二開關電路522。第二充電電路521用於接收第二致能訊號，並根據第二致能訊號輸出第二頻率切換訊號。第二開關電路522，用於接收迴授電路60迴授之流經第二燈管12的第二電流訊號，並在收到第二電流訊號後短路第二充電電路521之輸出。 The second frequency control circuit 52 includes a second charging circuit 521 and a second switching circuit 522. The second charging circuit 521 is configured to receive the second enable signal and output the second frequency switching signal according to the second enable signal. The second switch circuit 522 is configured to receive the second current signal flowing back through the second lamp 12 fed back by the feedback circuit 60, and short-circuit the output of the second charging circuit 521 after receiving the second current signal.
在本實施方式中，第二充電電路521包括第三電阻R3與第三電容C3。第三電阻R3一端用於接收第二致能訊號，其阻值較大，用於延時。第三電容C3一端連接於第三電阻R3的另一端，第三電容C3的另一端接地。當第二充電電路521接收到第二致能訊號後，經過第三電阻R3延時後對第三電容C3充電，並於第三電阻R3與第三電容C3之交接點輸出第二頻率切換訊號。 In the present embodiment, the second charging circuit 521 includes a third resistor R3 and a third capacitor C3. One end of the third resistor R3 is used to receive the second enable signal, and the resistance value is large for delay. One end of the third capacitor C3 is connected to the other end of the third resistor R3, and the other end of the third capacitor C3 is grounded. After receiving the second enable signal, the second charging circuit 521 charges the third capacitor C3 after being delayed by the third resistor R3, and outputs a second frequency switching signal at the intersection of the third resistor R3 and the third capacitor C3.
第二開關電路522包括第四電阻R4與第二電晶體Q2，第四電阻R4一端輸入迴授電路60所迴授之第二電流訊號，用於限流。第二電晶體Q2基極連接於第四電阻R4之另一端，其汲極連接於第三電阻 R3與第三電容C3之交接點，其射極接地。當第二開關電路522藉由第四電阻R4接收到第二電流訊號後，第二電晶體Q2之基極電壓升高，使得第二電晶體Q2導通，第二充電電路521之輸出經過第二電晶體Q2之汲極接地，則第二充電電路521停止向頻率切換電路40輸出第二頻率切換訊號。 The second switch circuit 522 includes a fourth resistor R4 and a second transistor Q2. One end of the fourth resistor R4 is input to the second current signal fed back by the feedback circuit 60 for current limiting. The base of the second transistor Q2 is connected to the other end of the fourth resistor R4, and the drain is connected to the third resistor The junction of R3 and the third capacitor C3 is grounded. After the second switch circuit 522 receives the second current signal through the fourth resistor R4, the base voltage of the second transistor Q2 rises, so that the second transistor Q2 is turned on, and the output of the second charging circuit 521 passes through the second. When the drain of the transistor Q2 is grounded, the second charging circuit 521 stops outputting the second frequency switching signal to the frequency switching circuit 40.
作為本發明一實施例之進一步改進，第二開關電路522更包括第四電容C4，一端連接於第四電阻R4之一端，另一端接地，用於對第二電流訊號進行濾波。 As a further improvement of an embodiment of the present invention, the second switch circuit 522 further includes a fourth capacitor C4, one end is connected to one end of the fourth resistor R4, and the other end is grounded for filtering the second current signal.
作為本發明一實施例之進一步改進，藉由調整第二充電電路521中第三電阻R3與第三電容C3的值來預設計數值，用於控制第二頻率切換控制電路52延時發送第二頻率切換訊號。當第二充電電路521接收到第二致能訊號時開始計數，第二頻率切換控制電路52若在預設計數值計數完後仍未接收到迴授電路60的第二電流訊號，則發送第二頻率切換訊號至頻率切換設置電路40。 As a further improvement of an embodiment of the present invention, the value is pre-designed by adjusting the values of the third resistor R3 and the third capacitor C3 in the second charging circuit 521 for controlling the second frequency switching control circuit 52 to delay transmitting the second frequency. Switch the signal. When the second charging circuit 521 receives the second enable signal, the second frequency switching control circuit 52 sends the second second signal if the second current signal of the feedback circuit 60 is not received after the pre-designed value is counted. The frequency switching signal is to the frequency switching setting circuit 40.
頻率切換設置電路40還包括第五電阻R5、第六電阻R6及第三電晶體Q3。第五電阻R5一端連接於PWM控制器41。第六電阻R6一端連接於PWM控制器41，另一端接地。第三電晶體Q3基極接收第一頻率切換控制電路51與第二頻率切換控制電路52之頻率切換訊號，其汲極連接於第五電阻R5之另一端。其中，當第三電晶體Q3接收到第一頻率切換訊號或第二頻率切換訊號時，第三電晶體Q3導通，使第五電阻R5與第六電阻R6所構成之並聯電路的阻抗降低。 The frequency switching setting circuit 40 further includes a fifth resistor R5, a sixth resistor R6, and a third transistor Q3. One end of the fifth resistor R5 is connected to the PWM controller 41. The sixth resistor R6 has one end connected to the PWM controller 41 and the other end grounded. The base of the third transistor Q3 receives the frequency switching signal of the first frequency switching control circuit 51 and the second frequency switching control circuit 52, and the drain thereof is connected to the other end of the fifth resistor R5. When the third transistor Q3 receives the first frequency switching signal or the second frequency switching signal, the third transistor Q3 is turned on, so that the impedance of the parallel circuit formed by the fifth resistor R5 and the sixth resistor R6 is lowered.
詳而言之，當第三電晶體Q3接收到第一頻率切換訊號或第二頻率切換訊號時，進入導通狀態，此時頻率切換設置電路40的阻抗相當於第五電阻R5與第六電阻R6並聯，阻抗較小。當第三電晶體Q3 沒有接收到第一頻率切換訊號或第二頻率切換訊號中的任何一個訊號時，進入截止狀態，此時頻率切換設置電路40的阻抗相當於是第六電阻R6，阻抗較大。 In detail, when the third transistor Q3 receives the first frequency switching signal or the second frequency switching signal, it enters an on state, and the impedance of the frequency switching setting circuit 40 is equivalent to the fifth resistor R5 and the sixth resistor R6. Parallel, the impedance is small. When the third transistor Q3 When any one of the first frequency switching signal or the second frequency switching signal is not received, the off state is entered. At this time, the impedance of the frequency switching setting circuit 40 is equivalent to the sixth resistor R6, and the impedance is large.
在本實施方式中，頻率切換設置電路40的阻抗不同，其流經PWM控制器41的電流則不同，阻抗越大，則電流越小，PWM控制器41輸出的頻率則越慢。 In the present embodiment, the impedance of the frequency switching setting circuit 40 is different, and the current flowing through the PWM controller 41 is different. The larger the impedance, the smaller the current, and the slower the frequency output from the PWM controller 41.
PWM控制器41包括燈管時鐘震盪器411與控制邏輯單元412，用於產生PWM控制訊號。燈管時鐘震盪器411用於根據第五電阻R5與第六電阻R6所構成的並聯電路阻抗的大小調整其輸出的頻率。在本實施方式中，當電流較大時，即第三電晶體Q3處於導通狀態時，燈管時鐘震盪器411產生的頻率較快，也就是使相應的第一燈管11或第二燈管12處於點燈模式(Striking Mode)。當電流較小時，即第三電晶體Q3處於截止狀態時，燈管時鐘震盪器411產生的頻率較慢，也就是使該等燈管11、12處於工作模式(Operation Mode)。控制邏輯單元412用於根據燈管時鐘震盪器411所產生的頻率輸出PWM控制訊號至圖1中電源轉換電路30。在本實施方式中，PWM控制訊號包括使該等燈管11、12進入點燈模式的PWM控制訊號或工作模式的PWM控制訊號。 The PWM controller 41 includes a lamp clock oscillator 411 and a control logic unit 412 for generating a PWM control signal. The lamp clock oscillator 411 is for adjusting the frequency of the output of the parallel circuit according to the magnitude of the impedance of the parallel circuit formed by the fifth resistor R5 and the sixth resistor R6. In the present embodiment, when the current is large, that is, when the third transistor Q3 is in the on state, the lamp clock oscillator 411 generates a faster frequency, that is, the corresponding first lamp 11 or the second tube. 12 is in the Striking Mode. When the current is small, that is, when the third transistor Q3 is in the off state, the lamp clock oscillator 411 generates a slower frequency, that is, the lamps 11, 12 are in an operation mode. The control logic unit 412 is configured to output a PWM control signal to the power conversion circuit 30 of FIG. 1 according to the frequency generated by the lamp clock oscillator 411. In this embodiment, the PWM control signal includes a PWM control signal that causes the lamps 11, 12 to enter a lighting mode or a PWM control signal of an operating mode.
作為本發明一實施例之進一步改進，雙燈管驅動電路還包括連接電路70，連接於第一頻率切換控制電路51、第二頻率切換控制電路52與頻率切換設置電路40之間，用於將第一頻率切換控制電路51輸出的第一頻率切換訊號及第二頻率切換控制電路52輸出的第二頻率切換訊號經由同一點，即第三電晶體Q3之基極傳送至頻率切換設置電路40，而彼此之間不會產生干擾。 As a further improvement of an embodiment of the present invention, the dual lamp driving circuit further includes a connecting circuit 70 connected between the first frequency switching control circuit 51, the second frequency switching control circuit 52 and the frequency switching setting circuit 40, for The first frequency switching signal outputted by the first frequency switching control circuit 51 and the second frequency switching signal output by the second frequency switching control circuit 52 are transmitted to the frequency switching setting circuit 40 via the same point, that is, the base of the third transistor Q3. There is no interference between them.
連接電路70包括第一二極體D1、第二二極體D2及第七電阻R7。第一二極體D1之陽極連接於第一頻率切換控制電路51，第二二極體D2的陽極連接於第二頻率切換控制電路52。第七電阻R7之一端連接至第一二極體D1與第二二極體D2之陰極，另一端連接於頻率切換設置電路40，用於將電流訊號轉換成電壓訊號。其中，第一二極體D1與第二二極體D2用於避免第一頻率切換控制電路51與第二頻率切換控制電路52之間的干擾。 The connection circuit 70 includes a first diode D1, a second diode D2, and a seventh resistor R7. The anode of the first diode D1 is connected to the first frequency switching control circuit 51, and the anode of the second diode D2 is connected to the second frequency switching control circuit 52. One end of the seventh resistor R7 is connected to the cathodes of the first diode D1 and the second diode D2, and the other end is connected to the frequency switching setting circuit 40 for converting the current signal into a voltage signal. The first diode D1 and the second diode D2 are used to avoid interference between the first frequency switching control circuit 51 and the second frequency switching control circuit 52.
在其他實施方式中，該等電阻之個數及阻值可依實際電路之需求靈活予以設定，不僅限於本實施方式所揭露者。 In other embodiments, the number and resistance of the resistors can be flexibly set according to the requirements of the actual circuit, and are not limited to those disclosed in the embodiment.
圖3為本發明之以工作模式成功驅動第二燈管12之示意圖。圖4為本發明之未能以工作模式驅動第二燈管12而啟動點燈模式驅動第二燈管12之示意圖。 Figure 3 is a schematic illustration of the successful operation of the second lamp tube 12 in an operational mode of the present invention. 4 is a schematic diagram of the invention for driving the second lamp tube 12 in the operating mode to activate the second lamp tube 12 in the lighting mode.
圖3與圖4皆係本發明之雙燈管驅動電路以接收到第一致能訊號為起始點。t1時間為雙燈管驅動電路接收到第二致能訊號的時間，在t1時間之前第一燈管11已經完成從點燈模式到工作模式的轉換。t2時間為計數時間終止時間，自從t1時間開始計數。若在t1至t2計數時間內第二燈管12無法以工作模式驅動，則在t2至t3時間內轉入點燈模式驅動，待接收到第二電流訊號後再進入工作模式。 3 and FIG. 4 are both the dual lamp driving circuit of the present invention starting from receiving the first enabling signal. The t1 time is the time when the dual lamp driving circuit receives the second enable signal, and the first lamp 11 has completed the transition from the lighting mode to the working mode before the time t1. The t2 time is the count time end time, counting since the time t1. If the second lamp 12 cannot be driven in the working mode during the counting time from t1 to t2, the lighting mode is driven in the time t2 to t3, and the working mode is entered after the second current signal is received.
從圖3的可以看出，若第二燈管12在t1至t2時間內成功以工作模式驅動的，則第一燈管11的電流訊號無異常，因此液晶顯示面板的平均亮度Nits(cd/m2)亦無異常亮度變化。從圖4的測量結果可以看出，若第二燈管12無法在t1至t2時間內以工作模式驅動，則轉以點燈模式驅動，此時第一燈管11會產生一定的干擾電流， 液晶顯示面板的平均亮度Nits(cd/m2)亦會在t2至t3時間內出現異常亮度變化。 As can be seen from FIG. 3, if the second lamp tube 12 is successfully driven in the operation mode during the time t1 to t2, the current signal of the first lamp tube 11 is not abnormal, so the average brightness of the liquid crystal display panel Nits (cd/ M2) There is also no abnormal brightness change. It can be seen from the measurement result of FIG. 4 that if the second lamp tube 12 cannot be driven in the working mode from t1 to t2, it is driven in the lighting mode, and the first lamp tube 11 generates a certain interference current. The average brightness Nits (cd/m2) of the liquid crystal display panel also exhibits an abnormal brightness change from t2 to t3.
因為本發明首先以工作模式驅動，只有在工作模式驅動不成功的情況下，才採用點燈模式，可以減少液晶顯示面板的平均亮度出現異常亮度變化的情況。 Since the present invention is first driven in the operating mode, the lighting mode is adopted only when the operating mode driving is unsuccessful, and the abnormal brightness variation of the average brightness of the liquid crystal display panel can be reduced.
本發明採用頻率切換控制電路50與頻率切換設置電路40，可以分別對第一致能訊號與第二致能訊號進行響應，實現第一燈管11與第二燈管12的非同步驅動，光效率與電效率都優於同步驅動的方式。同時利用迴授電路60與第二充電電路512的計數功能對第二燈管12的驅動方式進行選擇，使可調光的範圍增加，避免了面板瞬間亮度之異常變化。 The frequency switching control circuit 50 and the frequency switching setting circuit 40 can respectively respond to the first enable signal and the second enable signal to realize asynchronous driving of the first lamp 11 and the second tube 12, and the light is Both efficiency and electrical efficiency are superior to those of synchronous drives. At the same time, the driving mode of the second lamp tube 12 is selected by the counting function of the feedback circuit 60 and the second charging circuit 512, so that the range of the dimming is increased, and the abnormal change of the instantaneous brightness of the panel is avoided.
綜上所述，本發明符合發明專利要件，爰依法提出專利申請。惟，以上所述者僅為本發明之較佳實施例，舉凡熟悉本案技藝之人士，在爰依本案發明精神所作之等效修飾或變化，皆應包含於以下之申請專利範圍內。 In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. The above description is only the preferred embodiment of the present invention, and equivalent modifications or variations made by those skilled in the art of the present invention should be included in the following claims.
11‧‧‧第一燈管 11‧‧‧First lamp
12‧‧‧第二燈管 12‧‧‧Second light tube
20‧‧‧變壓電路 20‧‧‧Transformer circuit
21‧‧‧第一變壓電路 21‧‧‧First transformer circuit
22‧‧‧第二變壓電路 22‧‧‧Second transformer circuit
30‧‧‧電源轉換電路 30‧‧‧Power conversion circuit
31‧‧‧第一電源轉換電路 31‧‧‧First power conversion circuit
32‧‧‧第二電源轉換電路 32‧‧‧Second power conversion circuit
40‧‧‧頻率切換設置電路 40‧‧‧Frequency switching setting circuit
41‧‧‧PWM控制器 41‧‧‧PWM controller
50‧‧‧頻率切換控制電路 50‧‧‧frequency switching control circuit
51‧‧‧第一頻率切換控制電路 51‧‧‧First frequency switching control circuit
52‧‧‧第二頻率切換控制電路 52‧‧‧Second frequency switching control circuit
60‧‧‧迴授電路 60‧‧‧Return circuit
Claims (16)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW98106381A TWI432097B (en) | 2009-02-27 | 2009-02-27 | Double-lamp driving circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW98106381A TWI432097B (en) | 2009-02-27 | 2009-02-27 | Double-lamp driving circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| TW201032673A TW201032673A (en) | 2010-09-01 |
| TWI432097B true TWI432097B (en) | 2014-03-21 |
Family
ID=44854950
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| TW98106381A TWI432097B (en) | 2009-02-27 | 2009-02-27 | Double-lamp driving circuit |
Country Status (1)
| Country | Link |
|---|---|
| TW (1) | TWI432097B (en) |
-
2009
- 2009-02-27 TW TW98106381A patent/TWI432097B/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| TW201032673A (en) | 2010-09-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TWI233074B (en) | Controller and driving method for power circuits, electrical circuit for supplying energy and display device having the electrical circuit | |
| CN102612227B (en) | Mixed light adjusting circuit and mixed light adjusting method thereof | |
| TW478240B (en) | High-efficiency adaptive DC/AC converter | |
| US8143797B2 (en) | DC/AC inverter | |
| CN106105396B (en) | The controllable electric power of LED (light emitting diode) string drivings | |
| EP2916620A2 (en) | Hybrid dimming control techniques for LED drivers | |
| EP1933448A1 (en) | Mixed-mode DC/AC inverter | |
| JP2008067005A (en) | Triangular wave generating circuit, generating method, inverter using them, light-emitting device, and liquid crystal television | |
| CN101511142A (en) | Switch constant-current source circuit without feedback on load end | |
| KR100402091B1 (en) | The backlight driving circuit using Piezoelectric transformer | |
| CN102752906B (en) | Lighting device and illumination apparatus having the same | |
| TWI432097B (en) | Double-lamp driving circuit | |
| CN207925111U (en) | Backlight source driving circuit and liquid crystal display | |
| JP2012099353A (en) | Lighting device of discharge lamp and lighting control method thereof | |
| CN211378326U (en) | But LED drive circuit of switch control of adjusting luminance | |
| JP2008289319A (en) | Discharge tube power supply system and semiconductor integrated circuit | |
| CN101784150B (en) | Double-lamp tube driving circuit | |
| KR100760844B1 (en) | DC AC converter | |
| CN111194119A (en) | LED driving circuit and method capable of being controlled by switching and dimming | |
| TW545085B (en) | Circuit arrangement | |
| TWI239223B (en) | Driving of discharge lamp tube and apparatus for controlling light adjustment | |
| WO2015024277A1 (en) | Backlight drive circuit, electronic device and backlight drive method | |
| CN101533613B (en) | Drive control circuit, backlight module and drive method thereof | |
| KR200292350Y1 (en) | Illumination Controlling Apparatus | |
| CN113747634B (en) | Light modulator |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MM4A | Annulment or lapse of patent due to non-payment of fees |