养鸡场鸡舍灯光控制器系统设计
- 格式:doc
- 大小:1.04 MB
- 文档页数:20
智慧灯光设施控制系统设计方案智慧灯光设施控制系统的设计方案:1. 系统概述智慧灯光设施控制系统是利用先进的信息技术和传感器技术,实现对灯光设施的自动化管理和控制。
该系统通过对周围环境的感知和分析,智能调整灯光亮度、颜色和场景,以实现节能、舒适的照明效果,并具备远程监控和管理功能。
2. 硬件设计系统由主控制器、传感器、执行器和通信模块等组成。
主控制器负责接收传感器采集的环境信息,并根据预设的算法进行灯光控制策略的计算和调整。
传感器模块包括光强传感器、温度传感器和人体感应传感器,用于采集环境亮度、温度和人员活动等信息。
执行器模块包括灯具驱动器和色温调节器,用于控制灯具亮度和颜色。
通信模块用于与外部系统进行数据交互,实现远程监控和管理。
3. 软件设计系统软件分为下位机程序和上位机程序。
下位机程序运行在主控制器上,负责接收传感器数据、运行控制算法并向执行器发出控制指令。
上位机程序为远程监控和管理平台,可以通过网络连接与下位机通信,显示实时数据和报警信息,并进行参数配置和控制命令下发。
4. 控制算法设计系统的控制算法涉及灯光亮度调节、色温调节和场景切换等方面。
亮度调节算法根据环境亮度和人员活动进行自适应调整,达到舒适和节能的照明效果。
色温调节算法根据环境温度和时间等因素,自动调整灯光的色温,以提供符合人眼视觉习惯的照明效果。
场景切换算法根据不同场景的需求,自动调整灯光的亮度、色温和颜色,例如工作场所、会议场所和休闲场所等。
5. 远程监控和管理系统具备远程监控和管理功能,可通过上位机程序进行远程查看实时数据、报警信息和运行状态,实现远程控制和参数配置。
同时,系统可以与其他智能建筑系统集成,实现跨系统联动和协同控制。
6. 安全性设计系统的安全性设计包括数据加密传输、访问权限控制和系统备份等方面。
数据加密传输保证了数据的安全性,防止数据泄漏和篡改。
访问权限控制通过用户认证和授权,实现不同用户的权限管理,确保系统的安全性。
灯光控制系统设计简介本文档旨在设计一个灯光控制系统,用于实现对灯光的集中控制和智能化管理。
通过该系统,用户可以方便地控制和调节灯光亮度、颜色和模式,提升用户体验和节能效果。
系统需求1. 控制:系统应能够控制多个灯光设备,包括开关、亮度和颜色的调节。
2. 联动:系统应支持多个灯光设备之间的联动,实现不同场景下的灯光自动切换。
3. 定时:系统应具备定时开关灯和模式切换的功能,方便用户根据需求自动调整灯光状态。
4. 连接:系统应支持多终端连接,包括手机、平板等设备,方便用户在不同场景下控制灯光。
5. 智能化:系统应具备智能化管理功能,如通过光线传感器实现自动调节灯光亮度等。
设计方案硬件设备1. 灯光控制器:选择适合灯光控制的硬件设备,如智能灯泡、灯带等,并确保能够接入系统进行控制。
2. 网络设备:建立稳定可靠的局域网连接,以实现多终端的控制与联动。
3. 光线传感器:安装光线传感器,用于智能化管理和自动调节灯光亮度。
软件系统1. 控制界面:设计直观简洁的控制界面,支持灯光开关、亮度、颜色和模式的调节。
2. 联动设置:允许用户根据需求设置不同场景下的灯光联动,如晚上自动调暖色灯光。
3. 定时功能:提供定时开关灯和模式切换的功能,用户可根据需求设置自动化定时任务。
4. 连接管理:支持多终端连接管理,用户可使用手机、平板等设备进行灯光的控制和管理。
5. 智能化管理:通过光线传感器等智能设备实现自动调节灯光亮度,提升用户体验和节能效果。
实施计划1. 确定需求:明确用户对灯光控制系统的具体需求和功能要求。
2. 设计方案:根据需求设计灯光控制系统的硬件设备和软件系统。
3. 采购设备:购买所需的硬件设备和网络设备,确保设备的兼容性和稳定性。
4. 开发软件系统:开发控制界面、联动设置、定时功能、连接管理和智能化管理等软件功能。
5. 安装设备:安装灯光控制器、光线传感器等硬件设备,并建立稳定可靠的网络连接。
6. 测试和调试:对系统进行全面测试和调试,确保功能正常、稳定可靠。
Advances in Engineering Research (AER), volume 61International Conference on Mechanical, Electronic, Control and Automation Engineering (MECAE 2017)The Design of Chicken House Electronic Intelligent Lighting ApparatusBiqing Li 1, b, Zhao Li 2, a, Xiuru Tan 1, b1College of Mechanical and Electronic Engineering, Hezhou University, Hezhou Guangxi 542899,China2Management Engineering Department, Guangxi vocational and technical college ofcommunications, Liuzhou Guangxi 530000, Chinaa****************,b****************Keywords: Automatic lighting; photosensitive resistance, light control, the clock control. Abstract. This page proposed an automatic henhouse light filling system which used microcomputer as main control unit. It can be achieved light up in the daytime through the photoconductive resistance induction light intensity is insufficient; illuminated lighting at night in a fixed time. The System to sense and measure the light intensity by using photosensitive resistance and LM358 , then compares and output the measured value, and then SCM can control the LED light according to the variation of the output measured value. The System to achieved electricity saving and control the lighting time by using the clock chip DS1302 and batteries, to measure the indoor temperature and humidity by using DHT11 temperature and humidity chip, and to showed the current environment of temperature and humidity values and real time by using the 1602 chip. With the advantages of simple design, easy maintenance, cheap cost, the system can be widely used in the field of poultry breeding industry.1.IntroductionHenhouse electronic intelligence fill-in light system can automatically detect the intensity of the external light and control the automatic lighting of the lamp, so as to let people know the lighting intensity. People can set the range of lighting intensity; once the lighting intensity is below this range, the system can directly take measures to make the light intensity be within this range.2.Design ideaPrinciple of filling light. Chickens are very sensitive to the changes in light intensity. Under natural conditions, when spring comes, the sunshine duration is gradually extended, and the hens begin to lay eggs and reproduce. When autumn approaches, with the gradual shortening of the sunshine duration, the hens’ abilities to reproduce also gradually reduce, and then they moult one after the other, thus stop laying eggs. Modern laying hens still retain this nature, the changes of solar terms have great impacts on them. In order to keep a high laying rate during the laying period of laying hens, the daily lighting time must be maintained above 14 ~ 16 hours. As the season changes, the natural lighting sometimes cannot meet the demands for lighting time of laying hens during the laying period, so it is necessary to manually adjust the lighting.Design scheme. This scheme is based on the SCM STC89C52 chip. Photosensitive resistor and LM358 constitute photosensitive resistor access detection circuit. DS1302 and 2032 button cell constitute clock control circuit. DHT11 constitutes temperature and humidity testing circuit. LCD1602 constitutes display part. The relay, triode and 100W bulb constitute the lamp control circuit.The clock control is achieved by using SCM and DS1302: when there is an input signal, the corresponding pin of SCM is high level; when there is no input signal, and the time is between 4a.m. and 10p.m., the pin of SCM is the low level signal (set output signal), if not in this time period, the pin is still high level.After the SCM sends a starting signal, DHT11 switches from low-power mode to high-speed mode; after the host sends out the starting signal, DHT11 begins to send a response signal and 40bit data, and also trigger a signal acquisition. Select reading partial data, under this mode, DHT11 receives the starting signal and then triggers a temperature and humidity acquisition, and displays the value on the LCD 1602. If not receiving the starting signal sent by the host, DHT11 will not take the initiative to acquire temperature and humidity. After the data acquisition is completed, it will automatically switch to the low-speed mode.3.Hardware circuit designThe design is composed of SCM minimum system, light-operated detection circuit, clock control circuit, temperature and humidity induced circuit and display circuit.The system has no special requirements for the processing speed, so it choose STC89C52 SCM produced by STC Company. STC89C52 adds online debugging function, thus the development of this chip does not require expensive hardware emulator, and it realizes real-time emulation. All resources can be used by the user and can be programmed online or in the system. The design uses P0 port, P1 port, P2 port and P3 port of SCM, which realizes data reading and writing as well as LED lighting control. P3 port is used as the download port.Reset circuit. When the system is in normal working condition, after the oscillator is stable, if RST pin has a high level and maintains 2 machine cycles (24 clock cycles), the CPU can respond and reset the system. Reset is divided into manual reset and power-on reset. The system of this design adopts power-on automatic reset and a normally open button is connected in the circuit in parallel, press the switch for a certain period of time, it will be able to make the RST pin to a high level so as to reset the SCM. The reset circuit of the system is shown in Figure 1.Figure 1 Reset circuitCrystal oscillator circuit. There is a high-gain inverting amplifier used to form the oscillator inside STC89C52. The signal produced by the oscillator is sent to CPU to be used as CPU clock signal, so as to drive the CPU to generate the machine cycle that executes the command function. The SCM pins XTAL1 and XTAL2 are the input and output terminals of the amplifier.The oscillation circuit of the system is shown in Figure 2.Figure 2 Crystal oscillator circuitThe circuit consists of two parts: signal acquisition and signal processing.(1) Signal acquisition part of lighting intensity: Photosensitive resistor is used as signal acquisition device. Photosensitive resistor is a kind of photoelectric device based on photoconductivity effect. When there is no light, photosensitive resistance value (dark resistance) is very large, and the current (dark current) in the circuit is very small. When exposed to light, the conductivity of semiconductor materials increases, and the resistance decreases. The resistance value increases with the lighting decreases.(2) Signal processing part: This design uses the integrated voltage comparator LM358 as the core component for signal processing. Two lighting states of intensive light and darkness are converted to two voltage values V1 and V2, which are regarded as the input voltage of the comparator; the twocomparators set two reference voltages Vref1 and Vref2. The working process analysis is as follows: when the lighting is strong, V1> Vref1>Vref2, the output voltages of the two comparators are (5V, 0V). When the lighting is dark, V2< Vref2 < Vref1, the output voltages of the two comparators are (-5V, 5V). Thus, it completes the conversion from analog signal to digital signal.4.Software designThe program flow is shown in Figure 23. When the circuit begins to run, the program is initialized, and the first line of LCD shows the student number: 0910618014, the second line shows the name: HU XI. Then, the first line shows the time, and the second line shows the temperature and humidity. After the time program starts to run, the time display changes per second (synchronize with the seconds). When the second shows 60, the second returns to zero, minute plus one; when the minute shows 60, the minute returns to zero, hour plus one; when the hour shows 24, the hour returns to zero.5.ConclusionThis design only stimulates to control the henhouse light, so it just uses some light-emitting diodes to simulate the light used in the henhouse, and the 5V low-voltage power source is used to stimulate the 220V mains supply that drives the light in the henhouse. In reality, we can use 220V mains supply instead of the 5V power supply and the ordinary lighting lamp used in the henhouse instead of the light-emitting diodes. Besides, we can control the circuit lighting with the relay. Acknowledgements2016 The project of improving the basic ability of young teachers in Colleges and universities in Guangxi: “Design and development of elect ronic commerce platform of agricultural products based on Semantic Technology” (No, KY2016YB455).2015 college students' innovative training program: “Research on the application of value added travel experience in the mobile terminal of the ‘ethnic custom travel’ in Guangxi” (No 201511838070); & “The design and development HeYuanTong Campus Mobile Phone APP based on Android” (No 201511838034).Project of scientific research and technology development project of Hezhou: “Design and implementation of agricultural products e-commerce platform based on Semantic Technology” (No, Hekeneng 1506006).References[1] B.Q LI, Y.F LING, H.Y ZHANG, S.Y ZHENG: The Design And Realization of Cherry TomatoHarvesting Robot Based on IOT. International Journal of Online Engineering, 12(12), 23, (2016).[2] B.Q LI, W.L GUAN, S.Y Zheng, X.G Yue: OPTIMISATION DESIGN OF CORN PRECISIONSEEDER BASED ON MULTI-ROUTE AND MULTI-CHANNEL CONTROL. JOURNAL OF THE BALKAN TRIBOLOGICAL ASSOCIATION, 21(4A), 1215, (2015).[3] B.Q Li, Et Al, The Design Implementation Of The APP Of Experiencing Guangxi Folk Custom,In: PROCEEDINGS OF THE 2016 INTERNATIONAL CONFERENCE ON ECONOMICS AND MANAGEMENT INNOVATIONS, Wuhan, China, 2016, PP.47-50.[4] B.Q Li, Et Al, Intelligent Control Management System and Its Application, In: PROCEEDINGSOF THE 2016 INTERNATIONAL CONFERENCE ON ECONOMICS AND MANAGEMENT INNOVATIONS, Wuhan, China, 2016, PP.68-71.[5] B.Q Li, Et Al, Design And Implementation Of Tanks War Game Based On The Android Platform,In: PROCEEDINGS OF THE 2016 2ND WROKSHOP ON ADVANCED RESEARCH AND TECHNOLOGY IN INDUSTRY APPLICATIONS, Dalian, China, 2016, PP.963-966.。
畜牧场照明与电力供应设备的设计与配置随着畜牧业的发展,畜牧场的照明和电力供应设备的设计与配置变得越来越重要。
在一个有效的畜牧场中,适当的照明和可靠的电力供应是确保畜牧生产顺利开展的关键因素之一。
本文将讨论畜牧场照明与电力供应设备的设计与配置,从而帮助提高畜牧场的生产效率和质量。
首先,畜牧场的照明设计至关重要。
为了提供良好的工作环境和合适的光照条件,照明设备必须能够满足以下要求:1. 光照亮度:畜牧场的不同区域和功能区需要不同的光照亮度。
例如,饲养区域需要较高的光照,而休息区域则需要较暗的光线。
为了确保畜禽的生长和健康,应根据动物的特性和需求来确定适当的光照亮度。
2. 光照均匀性:为了避免阴影和光线不均匀的问题,照明设备应能够提供均匀的光照分布。
这可以通过合理设置灯具的数量和位置来实现。
3. 能源效率:考虑到能源消耗和环境保护,照明设备的能源效率也是一个重要的考虑因素。
LED照明灯具在提供合适照明的同时,能够显著减少能源消耗,因此是畜牧场照明的理想选择。
另外,电力供应设备的设计和配置对畜牧场的正常运行也至关重要。
以下是一些关键要点:1. 主电源:畜牧场的主电源应能够稳定地为各个功能区域提供电力供应。
主电源应配备过载保护装置和接地系统,以确保安全使用。
在电网不稳定的地区,备用发电机的配置也是必不可少的。
2. 输电线路:为了减少电流损耗和电压降低,应选择合适的导线和线缆来搭建输电线路。
电线和线缆应经得起环境的考验,并应根据电流负载和输电距离来选择合适的规格和材料。
3. 电力配电:根据畜牧场的规模和需求,电力配电系统应设计合理。
针对不同的区域和设备,应进行分类配电,确保电力供应的稳定性和可靠性。
配电箱和开关设备也应符合安全标准,并进行适当的维护和检查。
4. 紧急备用电源:为了避免因电力故障而导致的生产中断,畜牧场还应配置紧急备用电源。
柴油发电机和蓄电池是常见的备用电源,可以提供电力供应的储备和过渡。
最后,在设计和配置畜牧场的照明和电力供应设备时,还需要考虑以下几个方面:1. 环境适应性:畜牧场的照明和电力设备应能够适应多变的气候和环境条件。
鸡舍灯光控制器学院:能动学院年级专业:2008级机械电子工程学号:********姓名:樱凝指导教师:中国甘肃兰州目录中文摘要 (1)英文摘要 (1)引言 (2)1.方案论证 (2)2.系统设计2.1系统功能 (2)2.2总体设计 (3)2.2.1系统框图 (3)2.2.2各模块框图 (3)2.3原理简述 (4)2.3.1补光原理 (4)2.3.2电路原理 (4)2.4器件选择 (4)3.电路设计3.1直流稳压电源 (5)3.1.1直流稳压电源电路图 (6)3.1.2器件选择和参数计算 (6)3.2光照控制电路3.2.1光照控制电路电路图及原理 (6)3.2.2器件选择和参数计算 (6)3.3时钟控制电路3.3.1电子钟电路 (7)3.3.2逻辑控制电路 (9)3.4主电路3.4.1主电路图 (13)3.4.2说明 (13)3.5整体电路图 (13)3.6结果分析 (14)3.6.1直流稳压电源模块 (14)3.6.2CP模块 (15)3.6.3电子钟模块 (15)3.6.4控制模块 (15)4.结论 (16)参考文献 (17)摘要对鸡舍灯光控制方式进行分析,综合其优缺点提出一种合理的控制模式。
运用电子技术相关知识设计了鸡舍灯光自动控制电路。
采用光照控制电路和时钟控制电路组合控制,实现了对鸡舍进行自动补光。
解决了不同天气、不同季节鸡舍灯光控制复杂的问题。
核心部分是控制电路,其优劣决定了补光的合理性与准确性等整体性能。
设计过程中采用了加拿大Interactive Image Technologies Ltd.公司的设计软件Multisim7.0,通过电脑仿真来设计电路图,并测试其各个模块的功能,最终实现设计要求。
关键词:鸡舍补光;光照控制;时钟控制AbstractSheds light on the analysis of control, its advantages and disadvantages of the integrated control of a reasonable model. Knowledge of the use of electronic technology designed sheds light automatic control circuit. Illumination using the clock control circuit and control circuit combination of control, the realization of automatic sheds light up. Solution of different weather, different seasons sheds light control of complex issues. The core of the control circuits, their advantages and disadvantages determine the reasonableness of premium light, such as overall performance and accuracy. The design process used in Canada, Interactive Image Technologies Ltd. The company's design software Multisim7.0, through computer simulation to design schematics, and test the functions of its various modules, and ultimately the design requirements.Keywords: sheds light up; light control; clock control引言鸡舍的灯光控制是蛋鸡饲养中的重要一环。
根据鸡舍结构、饲养方式的不同,要确定相应的控制方法。
不同灯光控制器不仅控制原理不同,而且其适用范围也不同。
目前在实际生产采用的鸡舍灯光控制器的类型主要有:DF-24型可编程序定时控制器、KG-316型微电脑时控开关、渐开渐灭型灯光控制器、速开速灭型灯光控制器等,这些灯光控制器采用电脑芯片进行定时控制,价格比较昂贵。
也有采用石英钟或其它方式作定时控制的灯光控制器,有的就是简单的定时控制,有的带有光敏控制。
但其控制方式基本相同。
本设计采用常见的电子元器件实现光照控制和时钟控制相结合的控制电路。
与高端的鸡舍灯光控制器相比,虽然功能较少,精度不高,但实现了基本的控制功能,满足了实际需要,同时大大降低了成本,适合于中小规模的养鸡场。
与低端的鸡舍灯光控制器相比,功能比较完备,控制效果要更好。
1.方案论证系统的方案有三种:①恒光强电路设定鸡舍内的光照强度,对鸡舍内光照强度进行检测,与设定值比较后输出控制信号,控制补光设备补光,使鸡舍内的光照强度恒定。
②光照延时电路白天利用自然光照,傍晚从某一设定时刻开始补光,用延时装置控制补光设备补光一段时间。
③光照、时钟双控电路用时钟电路设定需要补光的时间段和不需要补光的时间段,在需要补光的时间段内,光照控制电路控制补光设备补光,使鸡舍内的光照强度恒定。
方案1比较容易实现,但不够科学,没有考虑鸡的生活习性,另外耗能也比较大;方案2节约了电能,充分利用了自然光,但不易实现凌晨补光和阴雨天的补光,延迟补光的开始时间也需要随着季节的改变而改变,不方便调节;方案3具有方案1、2的优点,同时弥补了其缺陷:在夜晚设定了不补光的时间段,使鸡能够休息好,在补光的时间段保持鸡舍内的光照强度恒定,在晴天实现了傍晚、凌晨双段补光,同时解决了阴雨天气补光的问题,在季节变换时也不需要调节。
因此采用方案3。
2.系统设计2.1系统功能该系统应具备以下功能:①在晴天实现日出前、日落后双段时间补光②在阴雨天可实现自动补光③季节交替时能自动调节补光时间的长短2.2总体设计2.2.1系统框图鸡舍灯光控制器的原理框图如下,电路包括以下几个部分:直流稳压电源、光照控制电路、时钟控制电路以及主电路。
图1 鸡舍灯光控制器原理框图2.2.2各模块框图直流稳压电源如图2:光照控制电路如图3:时钟控制电路如图4:图2直流稳压电源原理框图图3光照控制电路原理框图图4时钟控制电路原理框图主电路如图5:图5主电路原理框图2.3原理简述2.3.1补光原理补光原理如图6.图6 补光原理图如上图6所示,光照控制和时钟控制两种控制方式叠加在一起就是补光的实际效果,夏季补光实现了凌晨提前二个小时补灯光,天亮后接受自然光,天黑后延续二个小时补光。
随着昼夜时差;春、夏、秋、冬补光时间自行调节,冬季补光时间相对最长,补光时间可提前及延长4-5小时之久。
通过对光敏电阻的调整,还可以设定阴雨天全天自动补光的功能。
2.3.2电路原理如系统框图所示,对市电进行变压、整流、滤波、稳压后获得直流稳压电源,为光照控制电路、时钟控制电路提供低压直流电源;光照控制电路、时钟控制电路对控制量进行处理后控制主电路中补光设备的运行,进行补光。
直流稳压电源、光照控制电路、主电路为模拟电路;时钟控制电路为数字电路。
2.4器件选择表1:元器件明细表3.电路设计3.1直流稳压电源3.1.1直流稳压电源电路图考虑到直流稳压电源的输出电压固定,输出电流变化范围较小,可采用二极管稳压电路。
电路图如右图7:3.1.2器件选择和参数计算 输出电压:V U O 6= 负载电流:mA I L 40~10=UI 的选择:UI =(2~3)UZ=12~18V变压器的选择:变比k=220/(12~18)=12.2~18.3:1;可取k=15:1,此时UI=14.7V 稳压管的选择:V U U O Z 6==,mA I Z 60~5= 限流电阻的选择:Ω=Ω+-=+-=3.19340567.14max min Im max k I I U U R L Z z inΩ=Ω+-=+-=3.124106067.14min max Im min k I I U U R L Z z ax ;取Ω=150R电容的选择:取C=220μf整流二极管的选择:D1~D4选用IN4007 3.2光照控制电路3.2.1光照控制电路电路图及原理 使用光敏电阻将光强信号转化为电信号,通过晶体管放大后控制继电器的吸合,设计电路如右图8.根据光敏电阻的特点,在充足的自然光线下光敏电阻R3为低阻2K Ω ,这时晶体管Q1截止,继电器K 释放,当夜暮来临后光敏电阻呈高阻2M Ω,Q1饱和导通,继电器吸合,K 的常开触点接通补光灯泡供电回路。
3.2.2器件选择和参数计算V1即直流稳压电源的输出电压,为6VLED1为电源指示灯,mA I V U VD VD 20~5,6.1==图7 直流稳压电源电路图图8 光照控制电路电路图R1为保护电阻,Ω=Ω-=-=880~22020~56.1611k I U V R VD VD ,取Ω=4701R 晶体管Q1选择9013R3为光敏电阻,低阻2K Ω,高阻2M Ω R2取为6 K Ω 电位器R4的选择:对于Q1,Ω≈K r be 2,Q1导通时V U be 7.0=,故V V U r r R U be be be R 8.27.022623=⨯+=+= R3=2K Ω时应保证Q1可靠截止,[]()Ω=Ω-=+-=K K r R R U U V R be R R 52.1828.28.26)(23331min 4∥∥ R3=2M Ω时应保证Q1饱和导通,[]()Ω=-=+-=K K M r R R U U V R be R R 1.9828.28.26)(23331max 4∥∥ 故电位器R4取为10 K Ω继电器K1选择电压继电器,V U K 61=D1反并联在K1线圈两端,其反压保护作用,选用IN4007 3.3时钟控制电路 3.3.1电子钟电路 1.CP 模块CP 信号发生器是秒表电路的核心,其作用是产生一个标准频率的脉冲信号,振荡频率的精度和稳定度决定了电子钟的质量。
设计中采用555定时器与RC 组成多谐振荡器来实现。
设计CP 信号发生器如右图9所示。
考虑到计时最小单位为1s ,故设定输出的脉冲频率为1Hz ,周期T=1s ,占空比为2/3。
多谐振荡器振荡周期的计算公式如下:()()1s2ln 23/12ln 3/22ln 121211221211=+=+====+=C R R T T T TC R T T C R R T由于实际电路中要求R1、R2≥1K Ω,同时R1+R2≤3.3M Ω,故取C1=10μF ,代入上式计算得图9 CP 信号发生R1=R2=48 KΩ。