压力机压力测试仪毕业设计.doc

摘要
此设计为一压力测控仪,应用纯硬件电路,通过当前压力值和设定压力值的比较来自动控制输出。控制部分应用组合逻辑电路,结构简单,性能稳定。传感部分应用经典传感器电路,偏置电流小、失调小、增益高、共模抑制能力强、响应快、漂移低、性能稳、价格低廉。输出部分采用光电耦合防止由于高压引起的干扰。采用数码管作为本系统的显示部分,其体积小,功耗底,响应速度快,易于匹配,可靠性高和寿命长。该系统优点在于速度快,抗干扰能力强,可靠性高。
此压力测控仪实用价值高,在控制中实现了一表多路显示,减少了机械表的使用量,不但降低了生产设备成本,同时确保了生产过程的一致性,使生产效率及产品质量得到了较大提高。
关键字: 自动控制逻辑电路传感器
Abstract
The design topic of this subject is a instrument of the pressure measures and control, applied pure hardware electric circuit, pare the current pressure value with set up the pressure value to auto- control the exportation. The logical electric circuit of control is simple and stable. Classic electric circuit of sensor has many excellences such as excursion electric current and maladjustment is less, magnified ability is higher, feedback is faster, more stable and cheaper than others. Higher- voltage electric circuit, which adopts phototube, can prevent of the interferences. The LED is used as the manifestation of this system, its volume is smaller, and the power is less, responding to the speed quicker, apt to match, the dependable is high with life span long. The advantages of this system are quick, the anti- interference ability is strong, and the dependable is high.
This instrument’s the value of practice is very high, which realizes that single meter display many roads outputs, not only reduce the usage of the machine meter and equipments cost, but also insure the consistency of the production line at the same time, improve the efficiency and quantities.
Key words: auto-control logic circuit sensor
目录
引言 5
1、任务书 6
2、设计思路 6
3、主要电路设计原理与计算 7
、传感器的选择 7
、传感器的正确选用原则 7
、传感器信号处理及放大电路 11
、输出控制 12
、选择继电器 14
、通道选择 16
、显示部分 25
、电源部分 25
、变压器选择 27
、总装图简介 28
4、电路板 29
、电路板设计的一般原则 29
、电路板的选用 29
、电路板的尺寸 29
、布局 30
、布线 31
、焊盘 31
、大面积填充 32
、接地 32
、地线的共阻抗干扰 32
、任何连接地线 33
、抗干扰设计 33
、为增加系统抗电磁干扰能力应该采取的措施 33
、降低噪声与电磁干扰的窍门 34
、电路板设计指导 35