毕业论文基于单片机简易数控直流电压.doc

摘 要 本设计以AT89S52单片机为核心控制芯片，实现数控直流电源功能的方案。设计采用放大器构成源，实现了～+V，电压步进，纹波mV，具有较高的精度与稳定性12V和5V电源为系统供电。该电路的原理是通过MCU控制DA的输出电压大小，通过放大器放大，参考电压，真正的电压还是由电压模块LM350输出使用3数码管可以显示三位数一个小数位，比如可以显示V，采用动态扫描驱动方式。ABSTRACT The design is with the MCUAT89S52 for the core control chip,which carry out the project that the function of the number controls the direct current power supply.Designed with the precision of eight DA converter DAC0832, three-adjustable regulators LM350 and a UA741 Operational Amplifiers constitute Regulators source, the output voltage range of +1.4 V ~ +9.9 V, 0.1V voltage step NC Regulators Power, it has with high precision and stability and only have the biggest ripple of 10 mV. Meanwhile, the program used only five keys to achieve the convenience of the output voltage setting ,with setting value adjustments. It has three kinds of adjust function,which can carry out micro-adjustment (Stepping volume 0.1)and the coarse adjustment (Stepping volume 1). The show part we have adopted a three-dimensional digital pipe to show the output voltage value. And we designed the 12V and 5V power supply system for electricity. The principle of that electric circuit was that the output voltage size which passes the MCU to control DA, passing the amplifier amplification, and the voltage is the reference voltage of the LM350. And the real voltage is still the LM350 outputs are from the voltage mold piece. Making use of five buttons to adjustment voltages, and pass the total cathode Christian Trinity LED to display the outputs voltage .In this design I used 3 piece code tubes, which can show three position numbers, one of them is a fraction position. for example ,it can show a 5.90 Vs. In this design I adopt the scan to drive way is dynamic state sweep. With traditional steady press power supply to compare to have an operation convenience, the power supply stability high characteristics, its exportation electric voltage size adoption figures show. Keywords: Numerical Control, Steppi