英文文献及翻译

AT89C51 single-chip microcomputer-based controller, combined with
integrated temperature sensor AD590J composed of constant temperature
water temperature control system.
Chemical, chemical experiments and research on water temperature
requirements of high performance and accuracy, the current market
face chemistry, chemical experiments and study the high price of
heated water systems. In this paper, the design of single-chip
component AT89C51 from the temperature control system for people with
low-cost, high precision, intelligent control, etc.
The water temperature of the performance indicators are:
Temperature range: 0 ~ 1O0 ℃; temperature range: 0 ~ 99.9 ℃;
temperature: 0.4 ℃; heating power: 1000W.
Part of the hardware circuit
AT89C51 selected as the system CPU, it is a low-power, high -32-performance, 4kB flash chip programmable / erasable read-only memory
8-bit microcontroller COMS.
Block diagram of the system AT89C51 single-chip by chip, IO
expansion port 8255 chip, 8032 chip digital-to-analog conversion,
analog-to-digital conversion chip 0809, keyboard control, status
indication circuit, sampling circuit temperature thermostat control
circuit, driver circuit and display circuit, such as group into.
1.1 temperature sampling circuit
Temperature sampling circuit using AD590 current-mode
temperature-sensitive device of its stability and linearity are
better. When in AD590 for the current 273.2uA, temperature increase
1℃, the current increase in 1uA. The current is converted to voltage
signal by analog-to-digital converter ADC0809, AT89C51 single-chip
temperature monitoring and conversion. One resistor R measurement
using a low temperature coefficient of resistance, temperature
coefficient of 10 x l0_6 / ℃. When monitoring the temperature of lO0
℃ when generated in the resistor voltage 18.66V about, when the
temperature is 0 ℃ when generated in the resistance of about 1 3.66V
voltage, that is, at a temperature of 0 ~ 1O0 ℃ in resistance on
pressure drop resulting from bad to 5v. However, when the temperature
is 0 ℃ demodulation IC2 potential output allows for OV, the time
when 1O0 ℃ for IC2 output 5v, in the constant temperature water tank
3 installed AD590, which are located under the sink in the various
parts, using its monitoring of temperature changes in the market tank
in order to control the stirring motor to ensure uniform temperature
sink.
1.2 thermostat control circuit
Constant temperature control circuit from heating thermostat
temperature setting and the composition of the two parts of the
circuit. The thermostat circuit settings temperature to provide the -33-working conditions of the heating circuit, the circuit set by the
keyboard combination of software programming to achieve common. In
addition to each button and set the IO port connected to 8255, but
also through a door with the

AT89C51 and T0 timer connected so that
when the button is depressed immediately after the interruption to
the application AT89C51, 8255 inquiry, and at the same time the
functions of the corresponding control . One set is the key type from
the set and the AT89C51, D / A converter analog voltage measurement
is the AD590, after the detection signal AT89C51, D / A converter
provides analog, IC3 constitute a comparison amplifier, IC4 ratio
amplifier , BG1, BG2, T constitutes a thyristor conduction angle
control circuit, a single bipolar transistor oscillator circuit the
lower the frequency, SCR's on-the shorter the time the smaller the
heating power, on the contrary higher. Single-junction transistors
and the oscillation frequency by the ratio of amplifier output
voltage control, AT89C51 single-chip temperature settings through the
sample and the temperature difference after the value, after
amplification by comparison with the temperature change to mediate
voltage thyristor the conduction angle in order to achieve the
adjustment of heating power to meet the temperature requirements of
the waters of the thermostat.
1.3 Drive Circuit
When the 8255 high output corresponding IO port, the drive
transistor turn-on 9013, so that the relay action, in order to drive
the work of the relevant circuit. Significant choice for a show so
that the display to choose between the "settings" and "measurement".
1.4 Keyboard control and status indication circuit
With the 8255 connected to the IO port 8 and 9 LED button to
complete the common waters of the control thermostat and the
instructions state. In addition to each button with the 8255 -34-connected to the IO port, but also with AT89C51 it connected the
timer so that when the button is depressed immediately after the
interruption of AT89C51 applications, and query the status of 8255 in
order to carry out the functions of the corresponding control. 1.5
shows the circuit Display circuit using a half the number of table 4
show the temperature head waters of the measurement of temperature
and set temperature.
Skeleton of the software, contains initialization, configuration
subroutine, subroutines to deal with temperature, showing subroutine.
Completion of system initialization after power-on reset 8255 and
software initialization and pre-heated water for the water to wait
for work, and open the inlet solenoid valve, when the corresponding
button press interrupted when AT89C51, read 8255 the status of the
population to determine the function keys in order to call the
corresponding subroutine. Subroutine completed one set of the set
temperature function. Initialization settings for the "0o.0o", when
the choice set and to identify key addition and subtraction
operations for each click on the Settings button software settings
for the corresponding temperature of the addition and subtraction

operation count, and the value storage and display. Subroutine to
deal with the role of temperature is the temperature set values and
the difference to the SCR trigger circuit heating thermostat control.
2.1 The use of Pro / E to establish mold standard parts library
Family
Pro/E is part of the family table (or assembly, or the
characteristics of) a collection of these parts (or assembly or
characteristics) are broadly similar, but in 12 some small
differences, for example, fastening screws Hexagon many kinds of
specifications, but they seem to be like and to implement the same -35-function, so in the Pro / E in them as a part family is a very useful
table in the family the same as a table-driven components parts to be
identified. In Pro / E use group table has the following advantages:
1) simple and compact to create and store a large number of objects.
2) For the generation of standard parts to save a great deal of time
and work.
3) parts from a series of documents to generate change, do not have
to re-create and generate for each part.
4) In the parts to create tiny changes in the relationship do not
have to use to change the model.
Table feature allows three-dimensional mold standard parts
library and standard library mold the development and use of things
become very easy. The following guide to commonly used as an example
to create a lead-chu-chu series of standard parts. First, Pro / E in
the completion of the three-dimensional modeling guide column, and
the need to change the size parameters defined as symbols. To mark
the size of symbol table for the family members did not indicate the
size of the features of a non-changing, dependent on the existence of
other features.
Family Table is essentially constituted by the rows and
columns of the table to start, you can use the Pro / TABLE to create
and modify. Here contains examples and their appropriate values, the
use of specific projects were listed. Generic model is not in the
group table of the project be included in each instance will be
automatically generated in accordance with design intent, Family
Table, regardless of the merits of another to create a new table or
modify an existing table, you can add to the table project. The use
of the above-mentioned methods. Enterprises can die design in
accordance with the need to build their own three-dimensional mold
standard parts library.-36-2.2 The use of Pro / E to establish the standard mold base
library
In the use of Pro / E to establish the mold standard parts
library, in order to further improve the efficiency of die design,
quality and standardization, it is necessary to consider the
establishment of standard mold base library, the following discussion
of how to use Pro / E to establish the standard mold base. The
establishment of standard mold base the first thing to consider is
the business of pr

ocessing capacity punching equipment, punching
equipment to the processing capacity as well as equipment based on
the work table to consider the standard form of mold, practicality
and versatility will be higher. In the three-dimensional mold
standard parts library has been established under the premise of the
establishment of standards mold-base much to the convenience and
quick. First of all, to enter the Pro / ASSMBLY equipped) mode, with
the establishment of similar communities standard parts, the specific
path for the operation: ASSMBLY (components) -- Family Tab (Family
Table add-item (additional items)) -- Component (component), and then
choose to change to take place in the assembly of parts or components
as the assembly of the project group table, and in the assembly do
not need to change family (such as fasteners) you do not need to
select. instances in the assembly of the assembly according to the
agreed relationship between the automatically generated . other
aircraft such as the bending modulus, tensile modulus planes.
Taking full account of this, pressing equipment and typical
performance parameters under the premise of stamping parts, you can
use the same solution to create a standard mold base.
At present, some colleges and universities as a result of
provincial funding in the strained devices, laboratory equipment, -37-more backward, in chemistry and chemical engineering laboratories
still use a contact thermometer to control water temperature. In
order to overcome the factors that a lot of inconvenience to the
original based on the old thermostat has been designed transformation
of waters. Proved by the use of the design，to meet the current
chemistry, chemical engineering and research needs of the
experimental results.
针对化工早期接点温度计恒温水域控温存在的缺点，本文介绍了一种基于
AT89C51单片机为主控制器，结合AD590J集成温度传感器等组成的恒温水域温
控系统。
化学、化工实验及其研究对恒温水域的性能及精度要求很高，而目前市场上
面对化学、化工实验及研究的恒温水域系统价格很高。本文设计的由AT89C51单
片机组成的温控系统具有成本投人低，精度高、智能控制等优点。该恒温水域的
性能指标为：温控范围：0～IO0℃；温度设定范围：0～99.9℃；温差：
0．4℃；加热功率：1000W 。-38-本系统选用AT89C51作为CPU，它是一种低功耗、高性能、片内4kB快闪可编
程／擦除只读存储器的8位COMS微控制器。
该系统框图由AT89C51单片机芯片、IO口扩展芯片8255、数模转换芯片8032、模
数转换芯片0809、键盘控制、状态指示电路、温控采样电路恒温控制电路、驱动电
路和显示电路等组成。1.1 温度采样电
路
温度采样电路采用了AD590电流型温度敏感型器件其稳定度和线

性度均较
好。在0~C时AD590的电流为273.2uA，温度每增加1℃ ，电流增加1uA。该电流
转换为电压信号，通过模数转换ADC0809、AT89C51单片机实现温度的监测和转
换。其中电阻R采用低温度系数计量电阻，温度系数为10×l0_6／℃。当被监测
温度为lO0℃时在该电阻上产生约18．66V的电压，当温度为0℃时在该电阻上
产生约13．66V的电压，即在温度为0～1O0℃在电阻上产生的压降差为5v。但
当温度为0℃时解调电位器使IC2输出端为OV，当1O0℃时IC2输出端为5v，在
恒温水域的水槽内安装三只AD590，分别位于水槽上中下各部分，用其监测水
槽的温场变化，以便控制搅拌电机工作，保证水槽的温度均匀。
1．2 恒温控制电路
恒温控制电路由温度设定和恒温加热两部分电路组成。温度设定电路为恒温
加热电路提供工作条件，由键盘设定电路结合软件编程来共同实现。每一个设定
按键除与8255的IO 口相连外，还通过一个与门与AT89C51的定时器T0相连，
以便当按键按下后立即向AT89C51申请中断，查询8255口状态，同时进行相应
的功能控制。其中设定量是由设定键键入并经AT89C51、D／A转换的电压模拟量，
测量是AD590的检测信号经过AT89C51、D／A转换提供的模拟量，IC3构成比较
放大器，IC4构成比例放大器，BG1、BG2、T构成可控硅导通角控制电路，单结晶
体管振荡电路的频率越低，可控硅的导通时间越短加热功率越小，相反则高。而
单结晶体管的振荡频率受比例放大器输出电压控制，AT89C51单片机通过温度
设定值与温度采样值比较后的差值，经比较放大后产生随温度变化的电压值来
调解可控硅的导通角，从而实现对加热功率的调节，满足了恒温水域的恒温要
求。
1.3 驱动电路-39-当8255相应IO口输出高电平时，驱动三极管9013导通，使继电器动作，
从而驱动相关电路工作。显示选择用于使显示器在“设定值”和“测量值”之间
选择显示。
1.4 键盘控制和状态指示电路
与8255的IO口相连的8个按键和9个LED共同完成恒温水域的控制功能和
状态指示。其中每个按键除与8255的IO口相连外，还通过与AT89C51的定时器
哟口相连，以便当按键按下后立即AT89C51申请中断，并查询8255口状态，以
便进行相应的功能控制。
1.5 显示电路
显示电路采用一块4位半数字表头来显示恒温水域内的测量温度和设定温
度值。
软件部分主要包括初始化、设定子程序、恒温处理子程序、显示子程序。初始
化完成系统加电后对8255的复位和软件的初始化并将恒温水域预置为等待进水
工作状态，打开进水电磁阀，当有键按下时AT89C51相应中断，读取8255的口
状态，判

断按键的功能，以便调用相应的子程序。其中设定子程序完成温度的设
定功能。先进行初始化设定，当选择设定键并确定加减操作后每按一下设定键软
件就对温度设定值进行相应的加减计数操作，并将该值进行存储和显示。恒温处
理子程序的作用是将设定的温度值进行比较，并将该差值送给可控硅触发电路
进行加热恒温控制。
2.1 利用Pro／E建立模具标准件库
Pm／E的族表是零件(或装配或特征)的集合，这些零件(或装配或特征)基
本上是相似的，但在一两处有些微小的差别，例如，内六角紧固螺钉有许多种
规格，但它们看来是相象的并执行同样的功能，因此在Pro／E中把它们作为零
件族是非常有用的，在族表中的零件同样作为表驱动零件被识别。在Pro／E中
使用族表有以下几点好处：
1)简单紧凑地创建和存储大量对象。
2)对于标准件的生成节约了大量的时间和工作。
3)从一个零件文件生成系列变化，不必重新创建和生成每个零件。-40-4)在零件上创建微小的变化，不必使用关系去改变模型。
族表功能使三维模具标准件库及标准模架库的建立和使用成为很方便的事
情。下面以常用的导柱为例来建立导柱系列标准件。首先在Pro／E 中完成导柱
的三维造型，并把需要变化的尺寸定义为参数符号。以符号标注的尺寸为族表成
员，未标出的尺寸的特征为非变化的，依附于其它特征而存在。族表实质上是由
行和列构成的展开表，可以使用Pro／TABLE去创建和修改。这里包含了实例和
它们适当的值，列则被具体项目使用。类属模型未在族表中被包含的项目在每个
实例中会根据设计意图自动生成，族表的另一个优点是不论创建一个新表还是
修改一个已有的表，都可以向表中添加项目。运用上述方法。各企业可以根据模
具设计需要建立自己的三维模具标准件库。
2.2 利用Pro／E建立标准模架库
在利用Pro／E建立了模具标准件库后，为了进一步提高模具设计效率、质
量和标准化程度，有必要考虑建立标准模架库，下面讨论如何利用Pro／E建立
标准模架库。建立标准模架库首先要考虑的是本企业冲压设备的加工能力，以各
冲压设备的加工能力以及设备工作台面为依据考虑标准模架的形式，实用性和
通用性会更高一些。在三维模具标准件库已经建立的前提下，建立标准模架要方
便和快捷得多。首先要进入Pro／ASSMBLY 配备模式下工作，与建立零件标准件
族类似，具体操作路径为：ASSMBLY(组件)--Family Tab(族表 add-item(增加
项目))-- Component(元件)，然后选择在装配中要发生变化的零件或部件作为
装配族表的项目，而在装

配族中不需要变化的(例如紧固件)则不必选取。在装配
实例中按所约定的装配关系自动生成。其它的如弯曲模架、拉伸模架。在充分考虑
本冲压设备性能参数和典型冲压件的前提下，都可以用同样的解决方案来建立
标准模架库。
目前，部分省属高校由于设备经费较紧张、实验设备较落后，化学化工实验
室仍使用着接点温度计控制恒温水域。为克服其诸多不便因素，在原基础上对老
式恒温水域进行了设计改造。经使用证明该设计满足了目前化学、化工实验及研
究的需要，效果良好。