技术领域technical field
本发明涉及电源控制技术领域，尤其涉及一种低功耗的恒流与稳压控制电路及包括该低功耗的恒流与稳压控制电路的自适应供电调节的电视机。The invention relates to the technical field of power supply control, in particular to a low power consumption constant current and voltage stabilization control circuit and a television set including the low power consumption constant current and voltage stabilization control circuit for self-adaptive power supply regulation.
背景技术Background technique
线性恒流调制电路是模拟集成电路中广泛使用的一种单元电路，在实际中有着广泛的应用。其中，在LED电视机的电源控制技术领域中，往往利用前端电路输出恒压、后端电路实现升压或降压恒流来实现对主板和LED背光的供电。The linear constant current modulation circuit is a unit circuit widely used in analog integrated circuits, and has a wide range of applications in practice. Among them, in the technical field of power supply control of LED TVs, the front-end circuit is often used to output a constant voltage, and the back-end circuit is used to realize boost or step-down constant current to realize power supply to the main board and LED backlight.
在对电视机部件进行整合过程中，主板和背光灯条通常需要配套生产，而数量不同的背光LED灯条将需要线性恒流调制电路适应性输出不同的电压值。现有技术中采用一与电视机主板供电输出端连接的反馈回路，及时监控电视机主板供电输出端的电压变化。In the process of integrating TV components, the main board and the backlight strip usually need to be produced together, and the different numbers of backlight LED strips will require a linear constant current modulation circuit to adaptively output different voltage values. In the prior art, a feedback loop connected with the power supply output end of the main board of the TV set is adopted to monitor the voltage change of the power supply output end of the main board of the TV set in time.
如图1所示，是现有技术提供的一种线性恒流调制电路的原理图，通过电源电路10提供LED供电信号和主板供电信号。当主板供电输出端的输出电压升高时，通过电阻RB135与电阻RB134分压后的电压信号接入到稳压管UB102的参考输入端R0中，并将该电压信号与稳压管UB102内部的基准参考电压(如2.5V)作比较，使得稳压管UB102阴阳极之间电压降低，进而光耦二极管PCB101A的电流变大，集电极与发射极之间的动态电阻变小，集电极与发射极之间的电压变低；通过输出端ADJ/Vs-ON将电压信号的变化量反馈至电源电路10中的内部变压器；随之电源电路10中的内部变压器输出电压降低至设定的电压。因此，随着电阻RB134阻值的增大，LED供电输出端和主板供电输出端的输出电压减小，反之电压升高。As shown in FIG. 1 , it is a schematic diagram of a linear constant current modulation circuit provided in the prior art, and a power supply circuit 10 provides LED power supply signals and mainboard power supply signals. When the output voltage of the motherboard power supply output terminal rises, the voltage signal divided by the resistor RB135 and the resistor RB134 is connected to the reference input terminal R0 of the voltage regulator tube UB102, and the voltage signal is compared with the internal reference of the voltage regulator tube UB102 Compared with the reference voltage (such as 2.5V), the voltage between the cathode and anode of the voltage regulator tube UB102 decreases, and then the current of the optocoupler diode PCB101A increases, the dynamic resistance between the collector and the emitter becomes smaller, and the collector and emitter The voltage between them becomes lower; the variation of the voltage signal is fed back to the internal transformer in the power supply circuit 10 through the output terminal ADJ/Vs-ON; then the output voltage of the internal transformer in the power supply circuit 10 decreases to the set voltage. Therefore, as the resistance value of the resistor RB134 increases, the output voltages of the LED power supply output terminal and the motherboard power supply output terminal decrease, and vice versa, the voltage increases.
由于应用场合的不同，在实际生产过程中往往需要线性恒流电路输出不同的电压值，而现有技术为了满足不同场合需要，需要对硬件电路中的电阻RB134的阻值进行调整或更换电阻RB134。因此，该技术方案存在操作繁杂、精度低、功耗高和成本高的缺陷。此外，由于线性恒流电路的LED供电输出端和主板供电输出端的电压值同步变化，不同数量LED灯条所需要供电电压并不相同，而电视机主板的供电电压相对固定，因此，现有技术无法满足在调整LED供电输出端的输出电压值的同时，适应性地保持供给电视机主板的电压稳定的需求。Due to different application occasions, in the actual production process, the linear constant current circuit is often required to output different voltage values. However, in order to meet the needs of different occasions in the existing technology, it is necessary to adjust the resistance value of the resistor RB134 in the hardware circuit or replace the resistor RB134. . Therefore, this technical solution has the defects of complicated operation, low precision, high power consumption and high cost. In addition, since the voltage values of the LED power supply output terminal of the linear constant current circuit and the mainboard power supply output terminal change synchronously, the power supply voltage required by different numbers of LED strips is not the same, and the power supply voltage of the TV mainboard is relatively fixed. Therefore, the prior art It cannot meet the requirement of adaptively maintaining the voltage supply to the main board of the TV set while adjusting the output voltage value of the output terminal of the LED power supply.
发明内容Contents of the invention
本发明所要解决的技术问题是，提供一种低功耗的恒流与稳压控制电路，自适应地调整LED供电输出端的电压值和稳定供给主板的电压值，无需对硬件电路进行调整。The technical problem to be solved by the present invention is to provide a low power consumption constant current and voltage stabilization control circuit, which can adaptively adjust the voltage value of the output terminal of the LED power supply and the voltage value stably supplied to the main board without adjusting the hardware circuit.
为解决以上技术问题，一方面，本发明提供一种低功耗的恒流与稳压控制电路，包括：前端电源电路、DC-DC电压调节电路和后端线性恒流电路；In order to solve the above technical problems, on the one hand, the present invention provides a low power consumption constant current and voltage stabilization control circuit, including: a front-end power supply circuit, a DC-DC voltage regulation circuit and a rear-end linear constant current circuit;
所述前端电源电路包括供电电路、第一供电输出端、第二供电输出端和反馈电路；The front-end power supply circuit includes a power supply circuit, a first power supply output terminal, a second power supply output terminal and a feedback circuit;
所述反馈电路包括反馈输入端、控制信号输入端和反馈信号输出端；所述反馈输入端与所述第二供电输出端连接，所述反馈信号输出端与所述供电电路连接；所述反馈电路根据所述控制信号输入端的电压值，向所述供电电路输出反馈信号，以控制所述供电电路对所述第一供电输出端和所述第二供电输出端的电压值进行调整；The feedback circuit includes a feedback input terminal, a control signal input terminal and a feedback signal output terminal; the feedback input terminal is connected to the second power supply output terminal, and the feedback signal output terminal is connected to the power supply circuit; the feedback The circuit outputs a feedback signal to the power supply circuit according to the voltage value of the control signal input terminal, so as to control the power supply circuit to adjust the voltage values of the first power supply output terminal and the second power supply output terminal;
所述DC-DC电压调节电路的输入端与所述第二供电输出端连接，用于将所述第二供电输出端所输出的电压信号调节为固定的电压信号后，输出至主板进行供电；The input terminal of the DC-DC voltage regulating circuit is connected to the second power supply output terminal, and is used to adjust the voltage signal output by the second power supply output terminal to a fixed voltage signal, and output it to the main board for power supply;
所述后端线性恒流电路包括比较电路和恒流控制电路；所述比较电路设有参考信号输入端，以接入恒流参考电压；所述恒流控制电路在所述比较电路的调节下与待供电LED灯串的一端连接，所述待供电LED灯串的另一端与所述第一供电输出端连接；The back-end linear constant current circuit includes a comparison circuit and a constant current control circuit; the comparison circuit is provided with a reference signal input terminal to access a constant current reference voltage; the constant current control circuit is adjusted by the comparison circuit connected to one end of the LED light string to be powered, and the other end of the LED light string to be powered is connected to the first power supply output end;
在所述恒流控制电路与所述待供电LED灯串连接处引出一路电压采集输出端，以根据所述待供电LED灯串的电压变化，调整所述控制信号输入端的电压值，从而控制所述前端电源电路调整所述第一供电输出端、第二供电输出端的输出电压。A voltage acquisition output terminal is drawn from the connection between the constant current control circuit and the LED light string to be powered, so as to adjust the voltage value of the control signal input terminal according to the voltage change of the LED light string to be powered, thereby controlling the voltage of the LED light string to be powered. The front-end power supply circuit adjusts the output voltages of the first power supply output terminal and the second power supply output terminal.
进一步地，所述的低功耗的恒流与稳压控制电路还包括一控制主芯片；Further, the low power consumption constant current and voltage regulation control circuit also includes a control main chip;
所述控制主芯片与所述控制信号输入端、所述参考信号输入端以及所述电压采集输出端分别连接；The control main chip is respectively connected to the control signal input terminal, the reference signal input terminal and the voltage acquisition output terminal;
所述控制主芯片根据所述电压采集输出端的电压变化，调节输出至所述控制信号输入端的信号大小，以控制所述前端电源电路的第一供电输出端、第二供电输出端的输出电压值；并通过所述参考信号输入端向所述后端线性恒流电路输入所述恒流参考电压。The control main chip adjusts the signal size output to the control signal input terminal according to the voltage change of the voltage acquisition output terminal, so as to control the output voltage values of the first power supply output terminal and the second power supply output terminal of the front-end power supply circuit; And input the constant current reference voltage to the back-end linear constant current circuit through the reference signal input terminal.
进一步地，当所述控制主芯片检测到所述电压采集输出端与所述参考信号输入端的电压差值大于预设的阈值时，所述控制主芯片将输出至所述控制信号输入端的电压信号占空比减小。Further, when the control main chip detects that the voltage difference between the voltage acquisition output terminal and the reference signal input terminal is greater than a preset threshold, the control main chip outputs the voltage signal to the control signal input terminal The duty cycle is reduced.
进一步地，所述控制主芯片包括模数转换器，用于将所述控制主芯片接入的电压信号转换为数字信号。Further, the main control chip includes an analog-to-digital converter for converting the voltage signal connected to the main control chip into a digital signal.
优选地，所述供电电路包括电源输入电路、开关电源电路、多路输出变压器、LED供电输出电路和主板供电输出电路；Preferably, the power supply circuit includes a power input circuit, a switching power supply circuit, a multi-output transformer, an LED power supply output circuit, and a motherboard power supply output circuit;
所述电源输入电路在所述开关电源电路的控制下将接入的电源信号传输至所述多路输出变压器；The power input circuit transmits the input power signal to the multi-output transformer under the control of the switching power supply circuit;
所述多路输出变压器包括主绕组和副绕组；所述主绕组将所述电源信号变压后传输至所述主板供电输出电路，并通过所述第二供电输出端进行输出；所述副绕组将所述电源信号同步变压后传输至所述LED供电输出电路，并通过所述第一供电输出端进行输出；所述主绕组与所述副绕组的线圈匝数比为1：N，N＞0。The multi-output transformer includes a main winding and an auxiliary winding; the main winding transforms the power supply signal and transmits it to the main board power supply output circuit, and outputs it through the second power supply output terminal; the auxiliary winding The power supply signal is synchronously transformed and transmitted to the LED power supply output circuit, and output through the first power supply output terminal; the coil turns ratio of the main winding and the secondary winding is 1:N,N >0.
优选地，在所述前端电源电路中，所述反馈电路还设有光耦(PCB101)、稳压器(UB102)；Preferably, in the front-end power supply circuit, the feedback circuit is also provided with an optocoupler (PCB101) and a voltage regulator (UB102);
所述光耦(PCB101)包括位于原边的发光二极管和位于副边的光信号转换器；The optocoupler (PCB101) includes a light emitting diode on the primary side and an optical signal converter on the secondary side;
所述稳压器(UB102)将所述控制信号输入端输入的控制信号接入至所述光耦(PCB101)的位于原边的发光二极管；所述发光二极管将控制信号转换为光信号后传递至所述光耦(PCB101)的位于副边的光信号转换器；所述光信号转换器将光信号转换为电信号后输出至所述反馈信号输出端。The voltage regulator (UB102) connects the control signal input from the control signal input terminal to the light-emitting diode on the primary side of the optocoupler (PCB101); the light-emitting diode converts the control signal into an optical signal and transmits To the optical signal converter on the secondary side of the optocoupler (PCB101); the optical signal converter converts the optical signal into an electrical signal and outputs it to the feedback signal output end.
优选地，所述稳压器(UB102)采用可调试精密并联稳压器，包括阴极(K)、阳极(A)和参考输入端(R)，并内建有基准电压；Preferably, the voltage regulator (UB102) adopts an adjustable precision shunt voltage regulator, including a cathode (K), an anode (A) and a reference input terminal (R), and has a built-in reference voltage;
其中，所述可调试精密并联稳压器的阳极(A)接地，阴极(K)与所述光耦(PCB101)的位于原边的发光二极管连接；参考输入端(R)用于接入所述控制信号输入端的控制信号。Wherein, the anode (A) of the adjustable precision shunt voltage regulator is grounded, and the cathode (K) is connected to the light-emitting diode on the primary side of the optocoupler (PCB101); the reference input terminal (R) is used to access the The control signal at the control signal input terminal.
进一步地，所述反馈电路还设有稳压反馈电路。Further, the feedback circuit is also provided with a voltage stabilization feedback circuit.
另一方面，本发明还提供了一种自适应供电调节的电视机，包括：电视机主板、背光LED灯串，以及以上任一项所述的低功耗的恒流与稳压控制电路；On the other hand, the present invention also provides a TV set with self-adaptive power supply adjustment, including: a TV main board, a backlight LED light string, and the low power consumption constant current and voltage stabilization control circuit described in any one of the above;
所述低功耗的恒流与稳压控制电路与所述电视机主板和所述背光LED灯串分别连接，用于根据所述背光LED灯串的工作电压通过接入控制信号，自适应调节供给所述背光LED灯串的电压信号，并稳定输出至所述电视机主板的供电电压信号。The low power consumption constant current and voltage stabilization control circuit is respectively connected to the main board of the TV set and the backlight LED light string, and is used for self-adaptive adjustment according to the working voltage of the backlight LED light string by accessing a control signal The voltage signal is supplied to the backlight LED lamp string, and the power supply voltage signal is stably output to the main board of the TV set.
实施本发明提供技术方案，通过在线性恒流与稳压控制电路中设置前端电源电路、DC-DC电压调节电路和后端线性恒流电路，利用前端电源电路调节两路输出的供电电压，并在前端电源电路中建立反馈电路，以及在反馈电路中设有控制信号输入端，以实现对前端电源电路的第一供电输出端和第二供电输出端的电压的自动控制。由于控制信号输入端的电压信号将会同时影响第一供电输出端和第二输出端的输出电压，因此本发明进一步通过DC-DC电压调节电路来保证输出至主板的电压信号的稳定；并通过设立后端线性恒流电路自动适应串联的LED背光灯数量的变化，可以根据LED背光灯串联后的电压值调整所述控制信号输入端的电压值，从而通过前端电源电路及其反馈电路控制所述第一供电输出端、第二供电输出端的输出电压，而第一供电输出端连接至LED背光灯进行供电，实现了与LED背光灯数量相适应的电压自动化调节，降低电路开关元件的功耗，并保证了主板电路的供电电压的稳定性。进一步地，在电视机技术领域中，可以利用所述低功耗的恒流与稳压控制电路对电视机主板、背光LED灯串进行控制，实现一种自适应供电调节的电视机。Implementation of the present invention provides a technical solution, by setting a front-end power supply circuit, a DC-DC voltage regulation circuit and a rear-end linear constant current circuit in the linear constant current and voltage stabilization control circuit, using the front-end power supply circuit to adjust the power supply voltage of the two outputs, and A feedback circuit is established in the front-end power supply circuit, and a control signal input terminal is provided in the feedback circuit to realize automatic control of the voltages of the first power supply output terminal and the second power supply output terminal of the front-end power supply circuit. Since the voltage signal at the control signal input terminal will affect the output voltages at the first power supply output terminal and the second output terminal at the same time, the present invention further ensures the stability of the voltage signal output to the main board through a DC-DC voltage regulation circuit; and after setting up The terminal linear constant current circuit automatically adapts to changes in the number of LED backlights connected in series, and can adjust the voltage value of the control signal input terminal according to the voltage value of the LED backlights connected in series, so as to control the first The output voltage of the power supply output terminal and the second power supply output terminal, and the first power supply output terminal is connected to the LED backlight for power supply, which realizes the automatic voltage adjustment suitable for the number of LED backlight lamps, reduces the power consumption of the circuit switching elements, and ensures The stability of the power supply voltage of the motherboard circuit is ensured. Furthermore, in the field of television technology, the low power consumption constant current and voltage stabilization control circuit can be used to control the main board of the television and the backlight LED light string, so as to realize a television with self-adaptive power supply regulation.
附图说明Description of drawings
图1是现有技术提供的一种线性恒流调制电路的原理图。FIG. 1 is a schematic diagram of a linear constant current modulation circuit provided in the prior art.
图2是本发明提供的低功耗的恒流与稳压控制电路的一个实施例的结构示意图。FIG. 2 is a schematic structural diagram of an embodiment of a low power consumption constant current and voltage stabilization control circuit provided by the present invention.
图3是本发明提供的前端电源电路的一种可实现方式的原理图。FIG. 3 is a schematic diagram of a possible implementation of the front-end power supply circuit provided by the present invention.
图4是本发明提供的前端电源电路的一种具体电路原理图。Fig. 4 is a specific circuit principle diagram of the front-end power supply circuit provided by the present invention.
图5是本发明提供的DC-DC电压调节电路为升压调节电路时的一种电路原理图。Fig. 5 is a circuit schematic diagram when the DC-DC voltage regulation circuit provided by the present invention is a boost regulation circuit.
图6是本发明提供的后端线性恒流电路的一种可实现方式的电路原理图。FIG. 6 is a schematic circuit diagram of a realizable manner of the back-end linear constant current circuit provided by the present invention.
图7是本发明提供的低功耗的恒流与稳压控制电路的又一实施例的结构示意图。FIG. 7 is a structural schematic diagram of another embodiment of the low power consumption constant current and voltage stabilization control circuit provided by the present invention.
具体实施方式Detailed ways
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述。The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention.
参见图2，是本发明提供的低功耗的恒流与稳压控制电路的一个实施例的结构示意图。Referring to FIG. 2 , it is a schematic structural diagram of an embodiment of the low power consumption constant current and voltage stabilization control circuit provided by the present invention.
在本实施例中，所述的低功耗的恒流与稳压控制电路包括前端电源电路101、DC-DC电压调节电路102和后端线性恒流电路103。In this embodiment, the low power consumption constant current and voltage regulation control circuit includes a front-end power supply circuit 101 , a DC-DC voltage regulation circuit 102 and a rear-end linear constant current circuit 103 .
所述前端电源电路101包括供电电路1011、第一供电输出端OUT1、第二供电输出端OUT2和反馈电路1012；The front-end power supply circuit 101 includes a power supply circuit 1011, a first power supply output terminal OUT1, a second power supply output terminal OUT2 and a feedback circuit 1012;
其中，所述反馈电路1012包括反馈输入端A_in、控制信号输入端Cont和反馈信号输出端B_out；所述反馈输入端A_in与所述第二供电输出端OUT2连接，所述反馈信号输出端B_out与所述供电电路1011连接；所述反馈电路1012根据所述控制信号输入端Cont的电压值，向所述供电电路1011输出反馈信号，以控制所述供电电路1011对所述第一供电输出端OUT1和所述第二供电输出端OUT2的电压值进行调整。Wherein, the feedback circuit 1012 includes a feedback input terminal A_in, a control signal input terminal Cont, and a feedback signal output terminal B_out; the feedback input terminal A_in is connected to the second power supply output terminal OUT2, and the feedback signal output terminal B_out is connected to the second power supply output terminal OUT2. The power supply circuit 1011 is connected; the feedback circuit 1012 outputs a feedback signal to the power supply circuit 1011 according to the voltage value of the control signal input terminal Cont, so as to control the power supply circuit 1011 to the first power supply output terminal OUT1 and the voltage value of the second power supply output terminal OUT2 are adjusted.
参看图3，是本发明提供的前端电源电路的一种可实现方式的电路原理图。Referring to FIG. 3 , it is a circuit schematic diagram of an implementable mode of the front-end power supply circuit provided by the present invention.
在一种可实现方式中，如图3所示，反馈电路1012可设有光耦PCB101、稳压器UB102及其外围电路。其中，所述光耦PCB101包括位于原边的发光二极管(即光耦PCB101的脚1和脚2的组件)和位于副边的光信号转换器(即光耦PCB101的脚3和脚4的组件)。In a practicable way, as shown in FIG. 3 , the feedback circuit 1012 may be provided with an optocoupler PCB101 , a voltage regulator UB102 and its peripheral circuits. Wherein, the optocoupler PCB101 includes light-emitting diodes on the primary side (i.e. the assembly of pin 1 and pin 2 of the optocoupler PCB101) and an optical signal converter located on the secondary side (i.e. the assembly of pin 3 and pin 4 of the optocoupler PCB101) ).
稳压器UB102将所述控制信号输入端输入的控制信号接入至光耦PCB101的位于原边的发光二极管；所述发光二极管将控制信号转换为光信号后传递至所述光耦PCB101的位于副边的光信号转换器；所述光信号转换器将光信号转换为电信号后输出至所述反馈信号输出端。The voltage regulator UB102 connects the control signal input by the control signal input terminal to the light-emitting diode on the primary side of the optocoupler PCB101; An optical signal converter on the secondary side; the optical signal converter converts the optical signal into an electrical signal and outputs it to the feedback signal output end.
进一步地，所述反馈电路1012还设有电阻RB131和电阻RB132；所述电阻RB131的一端为所述反馈输入端，另一端与光耦PCB101的位于原边的发光二极管的阳极连接；所述电阻RB132的一端连接在所述发光二极管的阳极，另一端连接在所述发光二极管的阴极上。Further, the feedback circuit 1012 is also provided with a resistor RB131 and a resistor RB132; one end of the resistor RB131 is the feedback input end, and the other end is connected to the anode of the light-emitting diode on the primary side of the optocoupler PCB101; the resistor One end of RB132 is connected to the anode of the LED, and the other end is connected to the cathode of the LED.
其中，位于原边的发光二极管的输入端(脚1)通过电阻RB131作为反馈输入端A_in与第二供电输出端OUT连接，且光耦PCB101的原边两端(脚1和脚2)与电阻RB132并联；位于光耦PCB101的副边的光信号转换器的输出端(脚4)连接作为反馈信号输出端B_out与供电电路1011的反馈控制端feedback连接，光信号转换器的另一端(脚3)接地。需要说明的是，电阻RB132并非本实施例中的反馈电路中的必要电子元件。Wherein, the input terminal (pin 1) of the light-emitting diode on the primary side is connected to the second power supply output terminal OUT through the resistor RB131 as the feedback input terminal A_in, and the two ends of the primary side (pin 1 and pin 2) of the optocoupler PCB101 are connected to the resistor RB132 are connected in parallel; the output terminal (pin 4) of the optical signal converter located on the secondary side of the optocoupler PCB101 is connected as the feedback signal output terminal B_out and the feedback control terminal feedback of the power supply circuit 1011 is connected, the other end of the optical signal converter (pin 3 ) to ground. It should be noted that the resistor RB132 is not an essential electronic component in the feedback circuit in this embodiment.
稳压器UB102优选采用可调试精密并联稳压器，包括阴极K、阳极A和参考输入端R，并内建2.5V(伏)的基准电压，优选地，可采用型号为TL431的稳压器进行实现。其中，所述可调试精密并联稳压器的阳极A接地，阴极K与所述光耦PCB101的位于原边的发光二极管连接；参考输入端R用于接入所述控制信号输入端Cont的控制信号。The voltage regulator UB102 preferably adopts an adjustable precision shunt voltage regulator, including cathode K, anode A and reference input terminal R, and has a built-in reference voltage of 2.5V (volts). Preferably, a voltage regulator model TL431 can be used to implement. Wherein, the anode A of the adjustable precision shunt voltage regulator is grounded, and the cathode K is connected to the light-emitting diode on the primary side of the optocoupler PCB101; the reference input terminal R is used to access the control signal input terminal Cont Signal.
进一步地，所述反馈电路1012还设有稳压反馈电路。Further, the feedback circuit 1012 is also provided with a voltage stabilization feedback circuit.
在一种可实现的方式中，所述稳压反馈电路包括电容CB109和电阻RB133；所述电容CB109的一端连接在所述可调试精密并联稳压器的阴极K上，另一端与电阻RB133的一端串联；电阻RB133的另一端连接在所述可调试精密并联稳压器的参考输入端R上。In a practicable manner, the voltage stabilization feedback circuit includes a capacitor CB109 and a resistor RB133; one end of the capacitor CB109 is connected to the cathode K of the adjustable precision shunt regulator, and the other end is connected to the resistor RB133 One end is connected in series; the other end of the resistor RB133 is connected to the reference input end R of the adjustable precision shunt regulator.
在另一种可实现的方式中，所述稳压反馈电路包括电容CB110；所述电容CB110的一端连接在所述可调试精密并联稳压器的阴极K上，另一端连接在所述可调试精密并联稳压器的参考输入端R上。In another practicable manner, the voltage stabilization feedback circuit includes a capacitor CB110; one end of the capacitor CB110 is connected to the cathode K of the adjustable precision shunt regulator, and the other end is connected to the adjustable on the reference input R of the precision shunt regulator.
进一步地，本实施例可以将以上两种实现方式进行结合，以实现所述稳压反馈电路。即所述稳压反馈电路同时设有电容CB109、电阻RB133和电容CB110。Further, in this embodiment, the above two implementation manners may be combined to implement the voltage stabilization feedback circuit. That is, the voltage stabilizing feedback circuit is provided with a capacitor CB109, a resistor RB133 and a capacitor CB110 at the same time.
如图3所示，稳压器UB102的阴极K与光耦PCB101原边的发光二极管2脚连接，稳压器UB102的阳极A接地；电阻RB134的一端与稳压器UB102的参考输入端R连接，另一端接地；电容CB109的一端连接在所述可调试精密并联稳压器的阴极K上，另一端与电阻RB133的一端串联；电阻RB133的另一端连接在所述可调试精密并联稳压器的参考输入端R上；所述电容CB110的一端连接在所述可调试精密并联稳压器的阴极K上，另一端连接在所述可调试精密并联稳压器的参考输入端R上。As shown in Figure 3, the cathode K of the voltage regulator UB102 is connected to the light-emitting diode 2 pin of the primary side of the optocoupler PCB101, and the anode A of the voltage regulator UB102 is grounded; one end of the resistor RB134 is connected to the reference input terminal R of the voltage regulator UB102 , the other end is grounded; one end of the capacitor CB109 is connected to the cathode K of the adjustable precision shunt regulator, and the other end is connected in series with one end of the resistor RB133; the other end of the resistor RB133 is connected to the adjustable precision shunt regulator One end of the capacitor CB110 is connected to the cathode K of the adjustable precision shunt regulator, and the other end is connected to the reference input R of the adjustable precision shunt regulator.
进一步地，所述可调试精密并联稳压器的参考输入端R通过一分压器与所述控制信号输入端连接。在本实施例中，优选地，所述分压器为一电阻RB150。Further, the reference input terminal R of the adjustable precision shunt voltage regulator is connected to the control signal input terminal through a voltage divider. In this embodiment, preferably, the voltage divider is a resistor RB150.
如图3所示，电容CB109一端与光耦PCB101的2脚连接，另一端与电阻RB133串联后与电阻RB150的一端连接，电阻RB150的另一端作为所述控制信号输入端Cont；电容CB110的一端与稳压器UB102的阴极K连接，另一端与稳压器UB102的参考输入端R连接；电阻RB135的一端与反馈输入端A_in连接，另一端与稳压器UB102的参考输入端R连接。由此，构成了反馈电路1012的一种具体的实施方式。As shown in Figure 3, one end of the capacitor CB109 is connected to pin 2 of the optocoupler PCB101, the other end is connected in series with the resistor RB133 and then connected to one end of the resistor RB150, and the other end of the resistor RB150 is used as the control signal input terminal Cont; one end of the capacitor CB110 It is connected to the cathode K of the voltage regulator UB102, and the other end is connected to the reference input terminal R of the voltage regulator UB102; one end of the resistor RB135 is connected to the feedback input terminal A_in, and the other end is connected to the reference input terminal R of the voltage regulator UB102. Thus, a specific implementation manner of the feedback circuit 1012 is constituted.
在本实施例中，在稳压器UB102的参考输入端R上增加一电阻RB150，同时通过控制信号输入端Cont引入一控制信号对稳压器UB102的阴极K的输出电压值进行自动化控制，从而可实现对供电电路1011及其输出电压的调节。In this embodiment, a resistor RB150 is added to the reference input terminal R of the voltage regulator UB102, and a control signal is introduced through the control signal input terminal Cont to automatically control the output voltage value of the cathode K of the voltage regulator UB102, thereby Adjustment of the power supply circuit 1011 and its output voltage can be realized.
参看图4，是本发明提供的前端电源电路的一种具体电路原理图。Referring to FIG. 4 , it is a specific schematic circuit diagram of the front-end power supply circuit provided by the present invention.
所述供电电路1011包括电源输入电路11、开关电源电路12、多路输出变压器TB101、LED供电输出电路13和主板供电输出电路14；The power supply circuit 1011 includes a power input circuit 11, a switching power supply circuit 12, a multi-channel output transformer TB101, an LED power supply output circuit 13 and a motherboard power supply output circuit 14;
所述电源输入电路11在所述开关电源电路12的控制下将接入的电源信号传输至所述多路输出变压器TB101；如图4所示，所述多路输出变压器TB101包括主绕组和副绕组。其中，多路输出变压器TB101的9脚～11脚的线圈形成初级主绕组，多路输出变压器TB101的1脚～2脚的线圈形成次级主绕组；多路输出变压器TB101的7脚～8脚的线圈形成初级副绕组，多路输出变压器TB101的1脚～6脚的线圈形成次级副绕组，其中，1脚～2脚的线圈为主绕组和次绕组的共用绕组，需要说明的是，次级主、副绕组之间可以共用部分绕组，也可以采用独立的绕组。具体实施时，所述主绕组将所述电源信号变压后传输至所述主板供电输出电路14，并通过所述第二供电输出端OUT2进行输出；所述副绕组将所述电源信号同步变压后传输至所述LED供电输出电路13，并通过所述第一供电输出端OUT1进行输出；因此，图4中的多路输出变压器TB101具有两路输出电压，特别地，在电视机技术领域中，第一供电输出端OUT1优选为供给LED背光灯的供电输出端，第二供电输出端OUT2优选为供给电视机主板的供电输出端。The power input circuit 11 transmits the input power signal to the multi-output transformer TB101 under the control of the switching power supply circuit 12; as shown in FIG. 4, the multi-output transformer TB101 includes a main winding and a secondary winding. winding. Among them, the coils of pins 9 to 11 of the multi-output transformer TB101 form the primary main winding, and the coils of pins 1 to 2 of the multi-output transformer TB101 form the secondary main winding; the coils of pins 7 to 8 of the multi-output transformer TB101 The coil of the multi-channel output transformer TB101 forms the primary secondary winding, and the coils of pins 1 to 6 of the multi-channel output transformer form the secondary secondary winding. Among them, the coils of pins 1 to 2 form the common winding of the main winding and the secondary winding. It should be noted that, Part of the winding can be shared between the secondary primary and secondary windings, or independent windings can be used. During specific implementation, the main winding transforms the power signal and transmits it to the mainboard power supply output circuit 14, and outputs it through the second power supply output terminal OUT2; the secondary winding synchronously transforms the power signal After the voltage is transmitted to the LED power supply output circuit 13, and output through the first power supply output terminal OUT1; therefore, the multi-output transformer TB101 in FIG. 4 has two output voltages, especially in the field of television technology Among them, the first power supply output terminal OUT1 is preferably the power supply output terminal for supplying the LED backlight, and the second power supply output terminal OUT2 is preferably the power supply output terminal for supplying the TV mainboard.
在本实施例中，多路输出变压器TB101每匝线圈的输出电压是相同的，当改变其中一路的输出电压，那么另一路的输出电压也将会同步跟随变化。例如，主绕组的线圈为2匝，输出电压为12V，即每匝线圈的输出电压为6V；假设副绕组的输出电压为120V，则副绕组的线圈匝数为20匝。而主绕组和副绕组的线圈匝数可根据实际应用场合进行调整，即所述主绕组与所述副绕组的线圈匝数比为1：N，N＞0，即当主绕组的输出电压为V1时，副绕组的输出电压为V2＝N*V1。In this embodiment, the output voltages of each coil of the multi-output transformer TB101 are the same, and when the output voltage of one of them is changed, the output voltage of the other will also change synchronously. For example, the coil of the main winding has 2 turns, and the output voltage is 12V, that is, the output voltage of each turn of the coil is 6V; assuming that the output voltage of the secondary winding is 120V, the number of turns of the secondary winding is 20 turns. The number of coil turns of the main winding and the auxiliary winding can be adjusted according to the actual application, that is, the ratio of the number of turns of the main winding to the auxiliary winding is 1:N, N>0, that is, when the output voltage of the main winding is V1 , the output voltage of the secondary winding is V2=N*V1.
需要说明的是，反馈电路1012的反馈输入端A_in可连接所述供电电路1011的第一供电输出端OUT1或第二供电输出端OUT2，并不影响本实施例的实施。It should be noted that the feedback input terminal A_in of the feedback circuit 1012 can be connected to the first power supply output terminal OUT1 or the second power supply output terminal OUT2 of the power supply circuit 1011, which does not affect the implementation of this embodiment.
本发明可通过线性调节反馈电路1012的控制信号输入端Cont接入的外部控制信号的大小，从而控制第一供电输出端OUT1或第二供电输出端OUT2的电压值。具体地，以所述反馈电路1012的反馈输入端A_in连接到所述供电电路1011的第二供电输出端OUT2为例，本实施例的基本工作原理主要为：The present invention can control the voltage value of the first power supply output terminal OUT1 or the second power supply output terminal OUT2 by linearly adjusting the magnitude of the external control signal connected to the control signal input terminal Cont of the feedback circuit 1012 . Specifically, taking the feedback input terminal A_in of the feedback circuit 1012 connected to the second power supply output terminal OUT2 of the power supply circuit 1011 as an example, the basic working principle of this embodiment is mainly as follows:
当供电电路1011的输出电压升高(第一供电输出端OUT1和第二供电输出端OUT2同时升高)时，控制信号输入端Cont的控制信号经过电阻RB135和电阻RB134、电阻RB150分压后的电压传输至稳压器UB102的参考输入端R，稳压器UB102将参考输入端R的信号值与其内部基准电压进行比较。当参考输入端R的信号值大于基准电压时，稳压器UB102阴阳极之间的电压降低，进而光耦PCB101的电流增大，光耦PCB101集电极与发射极之间动态电阻变小(光耦PCB101的集电极为光耦的4脚，发射极为光耦的3脚)，集电极与发射极之间的电压变低；随之连接的PWM(Pulse Width Modulation，脉冲宽度调制)控制芯片UB101的反馈脚COMP的电平变低，PWM控制芯片UB101输出占空比减小，从而使得多路输出变压器TB101的输出电压降低。反之，当参考输入端R的信号值小于基准电压时，可使得多路输出变压器TB101的输出电压(包括第一供电输出端OUT1和第二供电输出端OUT2的输出电压)升高。When the output voltage of the power supply circuit 1011 rises (the first power supply output terminal OUT1 and the second power supply output terminal OUT2 rise simultaneously), the control signal of the control signal input terminal Cont is divided by the resistor RB135, the resistor RB134, and the resistor RB150. The voltage is transmitted to the reference input R of the voltage regulator UB102, and the voltage regulator UB102 compares the signal value of the reference input R with its internal reference voltage. When the signal value of the reference input terminal R is greater than the reference voltage, the voltage between the cathode and anode of the voltage regulator UB102 decreases, and then the current of the optocoupler PCB101 increases, and the dynamic resistance between the collector and emitter of the optocoupler PCB101 becomes smaller (optical The collector of the coupler PCB101 is the 4-pin of the optocoupler, and the emitter is the 3-pin of the optocoupler), and the voltage between the collector and the emitter becomes lower; the PWM (Pulse Width Modulation, pulse width modulation) control chip UB101 connected therewith The level of the feedback pin COMP becomes low, and the output duty cycle of the PWM control chip UB101 decreases, thereby reducing the output voltage of the multi-output transformer TB101. Conversely, when the signal value of the reference input terminal R is lower than the reference voltage, the output voltage of the multi-output transformer TB101 (including the output voltages of the first power supply output terminal OUT1 and the second power supply output terminal OUT2 ) can be increased.
因此，为调节稳压器UB102的参考输入端R接入的电压信号的大小从而控制变压器TB101的输出电压，本发明通过增加电阻RB150并在电阻RB150的一侧接入控制信号来实现这一目的。具体地，当需要调制第二供电输出端OUT2的输出电压，且稳压器UB102的内部基准电压为2.5V时，第二供电输出端的输出电压值计算公式为：Vout2＝基准电压*(1+R135/R134)，其中，基准电压优选为2.5V。优选地，可通过外部控制芯片输出一个PWM_12V信号至所述控制信号输入端Cont，经由电阻RB150将PWM_12V信号传输至电阻RB134与电阻RB135之间串联点(即稳压器UB102的参考输入端R)。Therefore, in order to adjust the magnitude of the voltage signal connected to the reference input terminal R of the voltage regulator UB102 and thereby control the output voltage of the transformer TB101, the present invention realizes this purpose by adding a resistor RB150 and connecting a control signal to one side of the resistor RB150 . Specifically, when the output voltage of the second power supply output terminal OUT2 needs to be modulated, and the internal reference voltage of the voltage regulator UB102 is 2.5V, the calculation formula of the output voltage value of the second power supply output terminal is: Vout2=reference voltage*(1+ R135/R134), wherein the reference voltage is preferably 2.5V. Preferably, an external control chip can output a PWM_12V signal to the control signal input terminal Cont, and transmit the PWM_12V signal to the series connection point between the resistor RB134 and the resistor RB135 (that is, the reference input terminal R of the regulator UB102) via the resistor RB150 .
具体实施时，控制信号输入端Cont的PWM_12V信号可采用0-3.3V中的任意一个恒定电压值，或者，采用一定波形的PWM(Pulse Width Modulation，脉冲宽度调制)波。根据第二供电输出端的输出电压值计算公式：Vout2＝基准电压*(1+R135/R134)，在任何情况下，当通过外部控制芯片向反馈电路1012的控制信号输入端Cont输入的控制信号为3.3V(最大)时，第二供电输出端OUT2的输出电压为最小，因为控制信号输入端Cont的输入电压(3.3V)大于稳压器UB102的基准电压2.5V(电路稳定工作的时候稳压器UB102的1脚电压和基准电压几乎相等)，所以此时相当于是电阻RB150接到3.3V的电源上，也就是相当于将电阻RB150并联在了电阻RB135上，根据Vout2的电压公式可知，由于电阻RB135并联了电阻RB150，相当于电阻RB135的等效电阻减少，从而使输出电压Vout2降低。当通过外部控制芯片向反馈电路1012的控制信号输入端Cont输入的控制信号为0V(最小)时，第二供电输出端OUT2的输出电压为最大，因为控制信号输入端Cont输入的控制信号为0V时相当于接地，这时相当于将电阻RB150并联在电阻RB134上，根据上述电压计算公式，由于电阻RB134并联了电阻RB150，相当于电阻RB135的等效电阻变小，从而使输出电压Vout2升高。During specific implementation, the PWM_12V signal at the control signal input terminal Cont can adopt any constant voltage value in the range of 0-3.3V, or use a PWM (Pulse Width Modulation, pulse width modulation) wave with a certain waveform. According to the calculation formula of the output voltage value of the second power supply output terminal: Vout2=reference voltage*(1+R135/R134), in any case, when the control signal input to the control signal input terminal Cont of the feedback circuit 1012 through the external control chip is When 3.3V (maximum), the output voltage of the second power supply output terminal OUT2 is the minimum, because the input voltage (3.3V) of the control signal input terminal Cont is greater than the reference voltage 2.5V of the regulator UB102 (when the circuit works stably The pin 1 voltage of the device UB102 is almost equal to the reference voltage), so at this time, it is equivalent to connecting the resistor RB150 to the 3.3V power supply, which is equivalent to connecting the resistor RB150 in parallel to the resistor RB135. According to the voltage formula of Vout2, because The resistor RB135 is connected in parallel with the resistor RB150, which is equivalent to reducing the equivalent resistance of the resistor RB135, thereby reducing the output voltage Vout2. When the control signal input to the control signal input terminal Cont of the feedback circuit 1012 through the external control chip is 0V (minimum), the output voltage of the second power supply output terminal OUT2 is the maximum, because the control signal input from the control signal input terminal Cont is 0V At this time, it is equivalent to connecting the resistor RB150 to the resistor RB134 in parallel. According to the above voltage calculation formula, since the resistor RB134 is connected in parallel to the resistor RB150, the equivalent resistance of the resistor RB135 becomes smaller, thereby increasing the output voltage Vout2 .
可见，通过线性调节反馈电路1012的控制信号输入端Cont输入的控制信号(例如上述的0V～3.3V的恒定电压信号或PWM波)，可使得第二供电输出端OUT2的输出电压在实际常用电压范围11.5V～12.5V之间进行调节(Vout2_max＝12.5V，Vout2_min＝11.5V)，从而实现微调；同理，在多路输出变压器TB101的作用下，第一供电输出端OUT1的输出电压也将实现同步自动适配调节。It can be seen that by linearly adjusting the control signal input by the control signal input terminal Cont of the feedback circuit 1012 (such as the above-mentioned constant voltage signal of 0V-3.3V or PWM wave), the output voltage of the second power supply output terminal OUT2 can be kept at the actual common voltage Adjust between 11.5V～12.5V (Vout2_max=12.5V, Vout2_min=11.5V), so as to realize fine-tuning; similarly, under the action of multi-output transformer TB101, the output voltage of the first power supply output terminal OUT1 will also be Realize synchronous automatic adaptation adjustment.
在具体应用场合中，在产品待机情况下(供电电路输出减少)，可通过线性调节外部控制芯片向反馈电路1012的控制信号输入端Cont输入的控制信号为高电平(如3.3V)，从而可使供电电路1011的第二供电输出端OUT2输出的电压为最小输出电压，可以减少电视机主板的待机功耗。In specific application occasions, when the product is in standby (the output of the power supply circuit is reduced), the control signal input to the control signal input terminal Cont of the feedback circuit 1012 by the external control chip can be linearly adjusted to a high level (such as 3.3V), thereby The voltage output by the second power supply output terminal OUT2 of the power supply circuit 1011 can be made to be the minimum output voltage, which can reduce the standby power consumption of the TV main board.
此外，所述待供电LED灯串由多个LED灯串联而成，随着待供电的LED灯串的数量的增多，多个LED串联后所需要的供电电压不断增高，因此，要求第一供电输出端OUT1的输出电压能够自适应地响应LED的数量变化，自动调节其输出电压值。In addition, the LED light string to be powered is composed of multiple LED lights connected in series. With the increase of the number of LED light strings to be powered, the power supply voltage required by the series connection of multiple LEDs is constantly increasing. Therefore, it is required that the first power supply The output voltage of the output terminal OUT1 can adaptively respond to the change of the number of LEDs, and automatically adjust its output voltage value.
由于第一供电输出端OUT1与第二供电输出端OUT2同属于一个变压器TB101，在对第一供电输出端OUT1的输出电压进行调节时，必然会对第二供电输出端OUT2的输出电压产生影响，而电视机主板的供电电压通常较为固定(约12V)，若第二供电输出端OUT2的输出电压幅度波动过大，将会影响电视机主板的整体性能，而过高的供电电压甚至可能烧毁电视机主板。Since the first power supply output terminal OUT1 and the second power supply output terminal OUT2 belong to the same transformer TB101, when the output voltage of the first power supply output terminal OUT1 is adjusted, the output voltage of the second power supply output terminal OUT2 will inevitably be affected. The power supply voltage of the main board of the TV is usually relatively fixed (about 12V). If the output voltage of the second power supply output terminal OUT2 fluctuates too much, it will affect the overall performance of the main board of the TV, and the power supply voltage that is too high may even burn the TV. machine motherboard.
如图2所示，本发明提供的低功耗的恒流与稳压控制电路还设有DC-DC电压调节电路102。具体地，所述DC-DC电压调节电路102的输入端与所述第二供电输出端OUT2连接，用于将所述第二供电输出端OUT2所输出的电压信号调节为固定的电压信号后，输出至电视机主板进行供电。As shown in FIG. 2 , the low power consumption constant current and voltage stabilization control circuit provided by the present invention is also provided with a DC-DC voltage regulation circuit 102 . Specifically, the input terminal of the DC-DC voltage regulating circuit 102 is connected to the second power supply output terminal OUT2, for adjusting the voltage signal output by the second power supply output terminal OUT2 to a fixed voltage signal, Output to TV motherboard for power supply.
以电视机主板所需供电电压为12V为例，本实施例在前端电源电路101与电视机主板之间增加一级DC-DC电压调节电路102，通过DC-DC电压调节电路102响应第二供电输出端OUT2的输出电压的变化，自动调节输出至电视机主板的供电电压值。DC-DC电压调节电路102可以根据第二供电输出端OUT2的输出电压大于或者小于12V的情况，采用降压调节电路或者升压调节电路。Taking the power supply voltage required by the main board of the TV set as an example, in this embodiment, a DC-DC voltage regulating circuit 102 is added between the front-end power supply circuit 101 and the main board of the TV set, and the DC-DC voltage regulating circuit 102 responds to the second power supply. The change of the output voltage of the output terminal OUT2 automatically adjusts the value of the power supply voltage output to the main board of the TV set. The DC-DC voltage regulation circuit 102 can use a step-down regulation circuit or a step-up regulation circuit according to whether the output voltage of the second power supply output terminal OUT2 is greater than or less than 12V.
参见图5，是本发明提供的DC-DC电压调节电路为升压调节电路时的一种电路原理图。当所述DC-DC电压调节电路102为升压调节电路时，包括：与所述第二供电输出端OUT2连接的电感器LB801、开关电路1021、电压转换芯片UB801及其外围电路1022，以及输出滤波电路1023；具体地，本实施例中可以通过将第二供电输出端OUT2的输出电压采用升压调节电路进行升压后得到12.5Vout给电视机主板供电。Referring to FIG. 5 , it is a circuit schematic diagram when the DC-DC voltage regulation circuit provided by the present invention is a boost regulation circuit. When the DC-DC voltage regulating circuit 102 is a boost regulating circuit, it includes: an inductor LB801 connected to the second power supply output terminal OUT2, a switch circuit 1021, a voltage conversion chip UB801 and its peripheral circuit 1022, and an output Filtering circuit 1023; specifically, in this embodiment, the output voltage of the second power supply output terminal OUT2 can be boosted by a boost regulator circuit to obtain 12.5Vout to supply power to the main board of the TV set.
所述开关电路1021与电感器LB801输出端连接，将所述第二供电输出端OUT2的电压信号传输至电压转换芯片UB801中调节为稳定的电压信号；再通过所述开关电路1021将调节后的稳定的电压信号传输至所述输出滤波电路1023进行过滤后，提供给电视机主板进行供电。The switch circuit 1021 is connected to the output terminal of the inductor LB801, and transmits the voltage signal of the second power supply output terminal OUT2 to the voltage conversion chip UB801 for adjustment to a stable voltage signal; The stable voltage signal is transmitted to the output filter circuit 1023 for filtering, and then provided to the TV main board for power supply.
为了实现自适应调节第一供电输出端OUT1的输出电压，同时保证供给电视机主板的电压信号的稳定性，本实施例在添加了DC-DC电压调节电路102后，则实现了第二供电输出端OUT2的输出电压的可调性。电视机主板允许的工作电压范围通常为11.5V～12.5V，则DC-DC电压调节电路102启动后作用是将第二供电输出端OUT2的输出电压进行调节后在12.5Vout输出端输出11.5V～12.5V的电压信号。In order to realize self-adaptive adjustment of the output voltage of the first power supply output terminal OUT1, and at the same time ensure the stability of the voltage signal supplied to the mainboard of the TV, this embodiment realizes the second power supply output after adding the DC-DC voltage regulation circuit 102 Adjustability of the output voltage of terminal OUT2. The allowable operating voltage range of the main board of the TV is usually 11.5V-12.5V, and the function of the DC-DC voltage regulating circuit 102 after starting is to adjust the output voltage of the second power supply output terminal OUT2 and then output 11.5V～12.5Vout output terminal. 12.5V voltage signal.
所述的线性恒流与稳压控制电路还设有后端线性恒流电路103，具体地，如图2所示，所述后端线性恒流电路103包括比较电路1031和恒流控制电路1032；所述比较电路1031设有参考信号输入端PWM_REF，以接入恒流参考电压VREF；所述恒流控制电路1032在所述比较电路1031的调节下与待供电LED灯串的一端LED-连接，所述待供电LED灯串的另一端LED+与所述第一供电输出端OUT1连接；The linear constant current and voltage stabilization control circuit is also provided with a back-end linear constant current circuit 103, specifically, as shown in Figure 2, the back-end linear constant current circuit 103 includes a comparison circuit 1031 and a constant current control circuit 1032 The comparison circuit 1031 is provided with a reference signal input terminal PWM_REF to access the constant current reference voltage VREF ; the constant current control circuit 1032 is regulated by the comparison circuit 1031 and one end of the LED lamp string to be powered is LED- connected, the other end LED+ of the LED light string to be powered is connected to the first power supply output end OUT1;
在所述恒流控制电路1032与所述待供电LED灯串连接处P引出一路电压采集输出端(如图2中的输出端ADC_12V)，以根据所述待供电LED灯串的电压变化，所述前端电源电路调整所述控制信号输入端Cont的电压值，从而控制所述第一供电输出端OUT1、第二供电输出端OUT2的输出电压。At the connection point P between the constant current control circuit 1032 and the LED lamp string to be powered, a voltage acquisition output terminal (such as the output terminal ADC_12V in FIG. 2 ) is drawn, so that according to the voltage change of the LED lamp string to be powered, the The front-end power supply circuit adjusts the voltage value of the control signal input terminal Cont, thereby controlling the output voltages of the first power supply output terminal OUT1 and the second power supply output terminal OUT2.
参看图6，是本发明提供的后端线性恒流电路的一种可实现方式的电路原理图。Referring to FIG. 6 , it is a circuit schematic diagram of an implementable mode of the back-end linear constant current circuit provided by the present invention.
具体实施时，在所述后端线性恒流电路103中，所述比较电路1031还包括运算放大器UB1A，所述运算放大器UB1A的反相输入端通过一电阻RB12与所述参考信号输入端PWM_REF连接；所述运算放大器UB1A的正相输入端连接有电流反馈电路。具体地，如图6所示，该电流反馈电路包括多个恒流检测电阻，分别为电阻RB5、电阻RB6、电阻RB7、电阻(RB8)、电阻RB9；其中，电阻RB6、电阻RB7、电阻RB8与电阻RB9组成并联电路，所述并联电路的一端连接在电阻RB5的一端上，所述并联电路的另一端接地；电阻RB5的另一端连接在所述运算放大器的正相输入端上。进一步地，所述电流反馈电路还包括电容CB5；所述电容CB5的一端接地，另一端连接在所述运算放大器的正相输入端上。其中电阻RB5和电容CB5组成的电路可以对输入到运算放大器UB1A的正相输入端的信号进行滤波。During specific implementation, in the back-end linear constant current circuit 103, the comparison circuit 1031 further includes an operational amplifier UB1A, and the inverting input terminal of the operational amplifier UB1A is connected to the reference signal input terminal PWM_REF through a resistor RB12 ; The non-inverting input terminal of the operational amplifier UB1A is connected with a current feedback circuit. Specifically, as shown in Figure 6, the current feedback circuit includes a plurality of constant current detection resistors, which are respectively resistor RB5, resistor RB6, resistor RB7, resistor (RB8), and resistor RB9; wherein, resistor RB6, resistor RB7, resistor RB8 Form a parallel circuit with the resistor RB9, one end of the parallel circuit is connected to one end of the resistor RB5, the other end of the parallel circuit is grounded; the other end of the resistor RB5 is connected to the non-inverting input of the operational amplifier. Further, the current feedback circuit further includes a capacitor CB5; one end of the capacitor CB5 is grounded, and the other end is connected to the non-inverting input end of the operational amplifier. The circuit composed of the resistor RB5 and the capacitor CB5 can filter the signal input to the non-inverting input terminal of the operational amplifier UB1A.
优选地，所述比较电路1031还包括一钳位二极管DB1，以保护所述比较电路1031的正常工作。Preferably, the comparison circuit 1031 further includes a clamping diode DB1 to protect the normal operation of the comparison circuit 1031 .
在所述后端线性恒流电路103中，所述恒流控制电路1032还包括一开关管QB1。开关管QB1可以为三极管或者MOS(Metal-Oxid-Semiconductor，金属氧化物半导体)场效应晶体管，简称MOS管或场效应晶体管。其中，开关管QB1的导通/截止状态跟其自身的物理特性相关联。例如，当开关管QB1为三极管时，根据三极管的伏安特性曲线，存在着饱和区、放大区和截止区，分别对三极管的发射极与集电极之间的电压信号产生不同的影响，如当三极管工作在饱和区时，三极管的发射极与集电极之间相当于短路(导通状态)。In the back-end linear constant current circuit 103, the constant current control circuit 1032 further includes a switch tube QB1. The switch tube QB1 may be a triode or a MOS (Metal-Oxid-Semiconductor, Metal-Oxid-Semiconductor) field effect transistor, referred to as a MOS tube or a field effect transistor. Wherein, the on/off state of the switch tube QB1 is related to its own physical characteristics. For example, when the switch tube QB1 is a triode, according to the volt-ampere characteristic curve of the triode, there are saturation regions, amplification regions and cut-off regions, which respectively have different effects on the voltage signal between the emitter and collector of the triode, such as when When the triode works in the saturation region, the emitter and collector of the triode are equivalent to a short circuit (conduction state).
在本实施例中，当所述开关管QB1为三极管时，所述恒流控制电路1032通过所述三极管的集电极与所述待供电LED灯串的一端(LED-)连接；所述三极管的发射极与所述钳位二极管DB1的阳极连接；当所述开关管QB1为场效应晶体管时，所述恒流控制电路1032通过所述场效应晶体管的漏极与所述待供电LED灯串的一端(LED-)连接；所述场效应晶体管的源极与所述钳位二极管DB1的阳极连接。In this embodiment, when the switching tube QB1 is a triode, the constant current control circuit 1032 is connected to one end (LED-) of the LED light string to be powered through the collector of the triode; The emitter is connected to the anode of the clamping diode DB1; when the switching tube QB1 is a field effect transistor, the constant current control circuit 1032 connects the drain of the field effect transistor to the LED light string to be powered. One terminal (LED-) is connected; the source of the field effect transistor is connected with the anode of the clamping diode DB1.
具体实施时，钳位二极管DB1的阴极接地，阳极通过电阻RB5连接在运算放大器UB1A的正相输入端。在后端线性恒流电路103启动后，经过运算放大器UB1A的调整，其正相输入端所连接恒流检测电阻所分得的电压值与其反向输入接入的恒流参考电压VREF相等，则当恒流参考电压VREF高于钳位二极管DB1的导通电压值(约0.7V)时，钳位二极管DB1将会导通接地，即由电阻RB6、电阻RB7、电阻RB8和电阻RB9并联组成的恒流检测电阻两端的电压值被钳位二极管DB1所限制，因此，钳位二极管DB1起到了一定的保护作用。During specific implementation, the cathode of the clamping diode DB1 is grounded, and the anode is connected to the non-inverting input terminal of the operational amplifier UB1A through the resistor RB5. After the back-end linear constant current circuit 103 is started, after adjustment of the operational amplifier UB1A, the voltage value obtained by the constant current detection resistor connected to its positive phase input terminal is equal to the constant current reference voltage VREF connected to its negative input terminal, Then when the constant current reference voltage VREF is higher than the conduction voltage value of the clamp diode DB1 (about 0.7V), the clamp diode DB1 will be turned on and grounded, that is, the resistance RB6, the resistance RB7, the resistance RB8 and the resistance RB9 are connected in parallel The voltage value at both ends of the composed constant current detection resistor is limited by the clamping diode DB1, therefore, the clamping diode DB1 plays a certain protective role.
并且，由于开关管QB1的发射极(开关管QB1为三极管)或源极(开关管QB1为MOS管)与钳位二极管DB1的阳极连接，因此流通开关管QB1的恒流值可以通过以下公式计算：In addition, since the emitter of the switching tube QB1 (the switching tube QB1 is a triode) or the source (the switching tube QB1 is a MOS tube) is connected to the anode of the clamping diode DB1, the constant current value of the switching tube QB1 can be calculated by the following formula :
当恒流参考电压VREF高于钳位二极管DB1的导通电压值时，流通开关管QB1的恒流信号为：I恒流＝DB1的导通电压值/恒流检测电阻的阻值；当恒流参考电压VREF低于钳位二极管DB1的导通电压值时，流通开关管QB1的恒流信号为：I恒流＝恒流参考电压VREF/恒流检测电阻的阻值。通常，钳位二极管DB1的导通电压值为0.7V，恒流检测电阻的阻值为电阻RB6、电阻RB7、电阻RB8和电阻RB9并联后的总阻值。When the constant current reference voltage VREF is higher than the conduction voltage value of the clamping diode DB1, the constant current signal flowing through the switch tube QB1 is: Iconstant current =the conduction voltage value of DB1/the resistance value of the constant current detection resistor; When the constant current reference voltage VREF is lower than the conduction voltage of the clamping diode DB1, the constant current signal flowing through the switch tube QB1 is: Iconstant current = constant current reference voltage VREF / resistance value of the constant current detection resistor. Usually, the conduction voltage of the clamping diode DB1 is 0.7V, and the resistance of the constant current detection resistor is the total resistance of the resistors RB6, RB7, RB8 and RB9 connected in parallel.
在本实施例中，第一供电输出端连接到LED灯串的正极LED+，通过开关管QB1的恒流控制，再串接恒流检测电阻(电阻RB6、电阻RB7、电阻RB8和电阻RB9的并联电阻)到地，恒流检测电阻将LED灯串的电流大小转换成电压信号接入到运算放大器UB1A与恒流参考电压VREF(由外部主芯片进行控制，或者接入固定电压，若为固定电压则输出的恒流值I恒流则为固定值，不能进行恒流大小的调节)进行比较和放大，从而控制开关管QB1调整LED灯串的电流保持恒定。In this embodiment, the first power supply output terminal is connected to the positive pole LED+ of the LED lamp string, and is controlled by the constant current of the switch tube QB1, and then connected in series with the constant current detection resistor (parallel connection of resistor RB6, resistor RB7, resistor RB8 and resistor RB9) Resistor) to ground, the constant current detection resistor converts the current of the LED light string into a voltage signal, which is connected to the operational amplifier UB1A and the constant current reference voltage VREF (controlled by an external main chip, or connected to a fixed voltage, if it is a fixed The voltage then outputs the constant current value I(constant current then is a fixed value, and the adjustment of the constant current size cannot be carried out) to compare and amplify, thereby controlling the switching tube QB1 to adjust the current of the LED light string to keep constant.
具体实施时，LED灯串一般会串联多颗LED灯，其中单颗LED的工作电压一般为2.8V～3.4V，多颗LED灯串联后的工作电压将相应增大。以开关管QB1为MOS管为例，开关管QB1的漏极与源极之间的电压：VDS＝VOUT1—LED灯串工作电压—恒流参考电压VREF。因此，后端线性恒流电路103进入工作状态后，开关管QB1的漏极与源极之间的电压VDS将会受到LED灯串的工作电压大小的影响，此外还可能受到多路输出变压器TB101的交叉调制(一般范围为7％)的影响。In practice, the LED light string generally connects multiple LED lights in series, and the working voltage of a single LED is generally 2.8V to 3.4V, and the working voltage of multiple LED lights in series will increase accordingly. Taking the switch tube QB1 as a MOS tube as an example, the voltage between the drain and the source of the switch tube QB1 is: VDS =VOUT1 —the working voltage of the LED light string—the constant current reference voltage VREF . Therefore, after the back-end linear constant current circuit 103 enters the working state, the voltage VDS between the drain and the source of the switching tube QB1 will be affected by the working voltage of the LED light string, and may also be affected by the multi-output transformer. Effect of TB101's intermodulation (7% typical range).
在现有技术中，随着LED灯串电压的变化，开关管QB1的漏源电压VDS电压也同步发生变化，开关管QB1的这部分功率(VDS*恒流值I恒流)将会转换成热量的形式散发出来，VDS电压越大，开关管QB1的功耗越大，温度越高。因此功耗过大的开关管QB1会降低电源效率并且导致开关管QB1过热而容易损坏。为了降低开关管QB1的温度，可以采用多个MOS管或三极管并联作为开关管QB1使用，但这一技术方案导致了成本的增加。为此，本实施例对后端线性恒流电路103作出进一步的改进。In the prior art, as the voltage of the LED light string changes, the drain-source voltage VDS voltage of the switch tube QB1 also changes synchronously, and this part of the power (VDS * constant current value Iconstant current ) of the switch tube QB1 will be Converted into heat and dissipated, the greater the VDS voltage, the greater the power consumption of the switch tube QB1, and the higher the temperature. Therefore, the switching tube QB1 with excessive power consumption will reduce the power supply efficiency and cause the switching tube QB1 to overheat and be easily damaged. In order to reduce the temperature of the switch tube QB1, multiple MOS tubes or triodes can be used in parallel as the switch tube QB1, but this technical solution leads to an increase in cost. For this reason, this embodiment makes further improvements to the back-end linear constant current circuit 103 .
参见图4～图6，本实施例通过在所述恒流控制电路1032与所述待供电LED灯串连接处P引出一路电压采集输出端ADC_12V，以实时检测待供电LED灯串的电压变化，为电压采集输出端ADC_12V与参考信号输入端PWM_REF之间的压降设定一个阈值，或者，为电压采集输出端ADC_12V的输出电压设定一个恒定值(参考信号输入端PWM_REF的电压VREF一般较小)，当电压采集输出端ADC_12V与参考信号输入端PWM_REF之间的压降大于所述阈值，或者电压采集输出端ADC_12V的输出电压大于所述恒定值时，通过调整前端电源电路101中的控制信号输入端Cont的控制信号PWM_12V，控制光耦PCB101将LED灯串的工作电压的变化情况(即第一供电输出端OUT1的电压变化情况)反馈到PWM控制芯片UB101，PWM控制芯片UB101控制开关管QB101改变占空比，从而使得电压采集输出端ADC_12V的电压值减去参考信号输入端PWM_REF的电压值等于或接近预设的所述阈值(或者电压采集输出端ADC_12V的电压值等于或接近所述恒定值)，因此，本实施例可以通过控制信号输入端Cont的控制信号PWM_12V，限定电压采集输出端ADC_12V与参考信号输入端PWM_REF之间的压降，从而减小开关管QB1的漏源电压VDS受到LED灯串的电压变化的影响，降低开关管QB1的功耗和保证了电源效率。Referring to Fig. 4 to Fig. 6, in this embodiment, a voltage acquisition output terminal ADC_12V is drawn at the connection point P between the constant current control circuit 1032 and the LED light string to be powered, so as to detect the voltage change of the LED light string to be powered in real time, Set a threshold value for the voltage drop between the voltage acquisition output terminal ADC_12V and the reference signal input terminal PWM_REF, or set a constant value for the output voltage of the voltage acquisition output terminal ADC_12V (the voltage VREF of the reference signal input terminal PWM_REF is generally lower than small), when the voltage drop between the voltage acquisition output terminal ADC_12V and the reference signal input terminal PWM_REF is greater than the threshold, or the output voltage of the voltage acquisition output terminal ADC_12V is greater than the constant value, by adjusting the control in the front-end power supply circuit 101 The control signal PWM_12V of the signal input terminal Cont controls the optocoupler PCB101 to feed back the change of the working voltage of the LED light string (that is, the change of the voltage of the first power supply output terminal OUT1) to the PWM control chip UB101, and the PWM control chip UB101 controls the switching tube QB101 changes the duty ratio so that the voltage value of the voltage acquisition output terminal ADC_12V minus the voltage value of the reference signal input terminal PWM_REF is equal to or close to the preset threshold (or the voltage value of the voltage acquisition output terminal ADC_12V is equal to or close to the constant value), therefore, this embodiment can limit the voltage drop between the voltage acquisition output terminal ADC_12V and the reference signal input terminal PWM_REF by controlling the control signal PWM_12V of the signal input terminal Cont, thereby reducing the drain-source voltage V of the switch tube QB1The DS is affected by the voltage change of the LED light string, which reduces the power consumption of the switching tube QB1 and ensures the power efficiency.
在本实施例中，由于第一供电输出端OUT1和第二供电输出端OUT2的输出电压均由多路输出变压器TB101所输出，则以上通过控制信号输入端Cont的控制信号PWM_12V来减小开关管QB1的功耗的同时，必然会使得多路输出变压器TB101的所有输出绕组的电压发生改变(即给电视机主板供电的第二供电输出端OUT2的输出电压也将发生改变)，但是，由于本实施例在第二供电输出端OUT2与电视机主板之间设有DC-DC电压调节电路102，因此本实施例能够防止因对前端电源电路的输出电压调整过大而导致电视机主板供电电源的变化范围过大的情况发生，而DC-DC电压调节电路102可以根据实际情况采用降压或者升压电路。In this embodiment, since the output voltages of the first power supply output terminal OUT1 and the second power supply output terminal OUT2 are both output by the multi-output transformer TB101, the control signal PWM_12V of the control signal input terminal Cont is used to reduce the voltage of the switching tube. While the power consumption of QB1 will inevitably make the voltages of all output windings of the multi-channel output transformer TB101 change (that is, the output voltage of the second power supply output terminal OUT2 that supplies power to the mainboard of the TV set will also change), but, due to this In this embodiment, a DC-DC voltage regulating circuit 102 is provided between the second power supply output terminal OUT2 and the main board of the TV set, so this embodiment can prevent the power supply of the main board of the TV set from being damaged due to excessive adjustment of the output voltage of the front-end power supply circuit. If the variation range is too large, the DC-DC voltage regulation circuit 102 can use a step-down or step-up circuit according to the actual situation.
本发明提供的一种低功耗的恒流与稳压控制电路，设置有前端电源电路、DC-DC电压调节电路和后端线性恒流电路，利用前端电源电路调节两路输出的供电电压，并在前端电源电路中建立反馈电路，以及在反馈电路中设有控制信号输入端，以实现控制前端电源电路在第一供电输出端和第二供电输出端的电压；由于控制信号输入端的电压信号将会同时影响第一供电输出端和第二输出端的输出电压，因此本发明进一步通过DC-DC电压调节电路来保证输出至主板电路的电压信号的稳定；并通过设立后端线性恒流电路自动适应串联的LED背光灯数量的变化，可以根据LED背光灯串联后的电压值调整所述控制信号输入端的电压值，从而通过前端电源电路及其反馈电路控制所述第一供电输出端、第二供电输出端的输出电压，而第一供电输出端连接至LED背光灯进行供电，实现了与LED背光灯数量相适应的电压自动化调节，降低电路开关元件的功耗，并保证了主板电路的供电电压的稳定性。The present invention provides a low power consumption constant current and voltage stabilization control circuit, which is provided with a front-end power supply circuit, a DC-DC voltage regulation circuit and a rear-end linear constant current circuit, and uses the front-end power supply circuit to adjust the power supply voltage of two outputs, And a feedback circuit is established in the front-end power supply circuit, and a control signal input terminal is provided in the feedback circuit, so as to realize controlling the voltage of the front-end power supply circuit at the first power supply output terminal and the second power supply output terminal; because the voltage signal at the control signal input terminal will It will affect the output voltage of the first power supply output terminal and the second output terminal at the same time, so the present invention further ensures the stability of the voltage signal output to the mainboard circuit through the DC-DC voltage regulation circuit; The change in the number of LED backlights connected in series can adjust the voltage value of the control signal input terminal according to the voltage value of the LED backlights connected in series, so as to control the first power supply output terminal and the second power supply output terminal through the front-end power supply circuit and its feedback circuit. The output voltage of the output terminal, and the first power supply output terminal is connected to the LED backlight for power supply, which realizes the automatic voltage adjustment suitable for the number of LED backlights, reduces the power consumption of the circuit switching elements, and ensures the power supply voltage of the motherboard circuit. stability.
参看图7，是本发明提供的低功耗的恒流与稳压控制电路的又一实施例的结构示意图。Referring to FIG. 7 , it is a structural schematic diagram of another embodiment of the low power consumption constant current and voltage stabilization control circuit provided by the present invention.
本实施例与前文所述的实施例的区别点在于，在前文所述的实施例的基础上，进一步地，本实施例提供的低功耗的恒流与稳压控制电路还包括一控制主芯片104。其中，前端电源电路101、DC-DC电压调节电路102和后端线性恒流电路103的基本构造与工作原理与前文所述的实施例相同，在此不再赘述。The difference between this embodiment and the aforementioned embodiments is that, on the basis of the aforementioned embodiments, further, the low power consumption constant current and voltage regulation control circuit provided by this embodiment also includes a control main chip 104 . Among them, the basic structure and working principle of the front-end power supply circuit 101 , the DC-DC voltage regulation circuit 102 and the back-end linear constant current circuit 103 are the same as those of the above-mentioned embodiments, and will not be repeated here.
所述控制主芯片104与所述控制信号输入端Cont、所述参考信号输入端PWM_REF以及所述电压采集输出端ADC_12V分别连接；The control main chip 104 is respectively connected to the control signal input terminal Cont, the reference signal input terminal PWM_REF and the voltage acquisition output terminal ADC_12V;
所述控制主芯片104根据所述电压采集输出端ADC_12V的电压变化，调节输出至所述控制信号输入端Cont的信号大小，以控制所述前端电源电路101的第一供电输出端OUT1、第二供电输出端OUT2的输出电压值；并通过所述参考信号输入端PWM_REF向所述后端线性恒流电路103输入所述恒流参考电压VREF。The control main chip 104 adjusts the magnitude of the signal output to the control signal input terminal Cont according to the voltage change of the voltage acquisition output terminal ADC_12V, so as to control the first power supply output terminal OUT1 and the second power supply output terminal OUT1 of the front-end power supply circuit 101. the output voltage value of the power supply output terminal OUT2; and input the constant current reference voltage VREF to the back-end linear constant current circuit 103 through the reference signal input terminal PWM_REF.
具体地，当所述控制主芯片104检测到所述电压采集输出端ADC_12V与所述参考信号输入端PWM_REF的电压差值大于预设的阈值时，所述控制主芯片104将输出至所述控制信号输入端Cont的电压信号占空比减小。具体实施时，所述控制主芯片104内置有模数转换器，用于将所述控制主芯片104接入的电压信号转换为数字信号。从电压采集输出端ADC_12V采集获得的电压信号首先经过模数转换器的转换后，获得相应的数字信号，再通过控制主芯片104中的其它处理单元的处理。Specifically, when the control main chip 104 detects that the voltage difference between the voltage acquisition output terminal ADC_12V and the reference signal input terminal PWM_REF is greater than a preset threshold, the control main chip 104 will output to the control The duty cycle of the voltage signal at the signal input terminal Cont decreases. During specific implementation, the control main chip 104 has a built-in analog-to-digital converter for converting the voltage signal connected to the control main chip 104 into a digital signal. The voltage signal collected from the voltage collection output terminal ADC_12V is first converted by an analog-to-digital converter to obtain a corresponding digital signal, and then processed by controlling other processing units in the main chip 104 .
本实施例由于采用了同一个控制主芯片对控制信号输入端Cont、所述参考信号输入端PWM_REF以及所述电压采集输出端ADC_12V三个端子的信号进行处理，因此在前文所述的有效效果的基础上，进一步地可以实时依据参考信号输入端PWM_REF以及电压采集输出端ADC_12V的信号变化而向控制信号输入端Cont发出相应的控制信号，因此可以迅速对LED灯串工作电压的变化进行响应。In this embodiment, the same control main chip is used to process the signals of the three terminals of the control signal input terminal Cont, the reference signal input terminal PWM_REF, and the voltage acquisition output terminal ADC_12V, so the effective effect described above On the basis, it can further send corresponding control signals to the control signal input terminal Cont according to the signal changes of the reference signal input terminal PWM_REF and the voltage acquisition output terminal ADC_12V in real time, so it can quickly respond to the change of the working voltage of the LED light string.
本发明实施例还提供了一种自适应供电调节的电视机，包括：电视机主板、背光LED灯串，以及前文任一项所述的低功耗的恒流与稳压控制电路。An embodiment of the present invention also provides a TV with self-adaptive power supply regulation, including: a TV main board, a backlight LED light string, and the low power consumption constant current and voltage stabilization control circuit described in any one of the preceding items.
其中，所述低功耗的恒流与稳压控制电路与所述电视机主板和所述背光LED灯串分别连接，用于根据所述背光LED灯串的工作电压通过接入控制信号，自适应调节供给所述背光LED灯串的电压信号，并稳定输出至所述电视机主板的供电电压信号。Wherein, the low power consumption constant current and voltage stabilizing control circuit is respectively connected with the main board of the TV set and the backlight LED light string, and is used to automatically control the signal by accessing the control signal according to the working voltage of the backlight LED light string. Adaptively adjust the voltage signal supplied to the backlight LED lamp string, and stably output the power supply voltage signal to the main board of the TV set.
本实施例利用改进后的线性恒流与稳压控制电路，应用在电视机领域中而对电视机主板、电视机背光LED灯串的供电信号进行控制。具体地，利用第一供电输出端OUT1自动根据背光LED灯串数量的变化而调整输出电压；利用DC-DC电压调节电路对第二供电输出端的电压进行升压或降压处理，从而对供给电视机主板的电压信号进行固定，因此保证供给电视机主板的电压信号不受背光LED灯条数量的变化的影响；既实现了与LED背光灯数量相适应的电压自动化调节，降低电路开关元件的功耗，又保证了电视机主板的供电电压的稳定性。以上所述是本发明的优选实施方式，应当指出，对于本技术领域的普通技术人员来说，在不脱离本发明原理的前提下，还可以做出若干改进和润饰，这些改进和润饰也视为本发明的保护范围。In this embodiment, the improved linear constant current and voltage stabilization control circuit is applied in the field of television to control the power supply signals of the main board of the television and the LED lamp strings of the television backlight. Specifically, use the first power supply output terminal OUT1 to automatically adjust the output voltage according to the change in the number of backlight LED lamp strings; The voltage signal of the main board of the TV set is fixed, so that the voltage signal supplied to the main board of the TV is not affected by the change of the number of backlight LED strips; it not only realizes the automatic adjustment of the voltage corresponding to the number of LED backlight lights, but also reduces the power of the circuit switching components power consumption, and ensure the stability of the power supply voltage of the TV motherboard. The above description is a preferred embodiment of the present invention, it should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications are also considered Be the protection scope of the present invention.
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410476653.7ACN104253955B (en) | 2014-09-17 | 2014-09-17 | Low-power-consumption constant-current and voltage-stabilizing control circuit and television |
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410476653.7ACN104253955B (en) | 2014-09-17 | 2014-09-17 | Low-power-consumption constant-current and voltage-stabilizing control circuit and television |
| Publication Number | Publication Date |
|---|---|
| CN104253955Atrue CN104253955A (en) | 2014-12-31 |
| CN104253955B CN104253955B (en) | 2017-09-12 |
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410476653.7AActiveCN104253955B (en) | 2014-09-17 | 2014-09-17 | Low-power-consumption constant-current and voltage-stabilizing control circuit and television |
| Country | Link |
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| CN (1) | CN104253955B (en) |
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