单片机--at89c51单片机控制的恒温水域温控系统—-毕业论文设计

AT89C51 single-chip temperature-controlled water temperature control system Early contact thermometers for chemical water temperature thermostat shortcomings, this paper introduces an approach based on 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 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, AT89...