理化实验室环境参数显示屏的研制

Development of display screen for environment parameters in physical and chemical laboratory

探讨了理化实验室环境参数显示屏的工作原理,通过各个电路的匹配设计,即根据A/D转换集成电路的输入电平以及各个传感器的输出电平的大小,将各个通道的放大倍数设置不一样,目的是最终到A/D转换集成电路的信号电平基本相等,这样可以利用大气参数变化缓慢的特点,用MCU控制电子开关实现多个通道共用一个采样电路.在采样的间隙,用MCU读时钟模块,刷新日期.多套系统通过近半年的运行,试验结果表明:系统可靠性和测试精度满足要求.

The principle of display screen for environment parameters is presented in this paper. Through matching design of circuits, in which according to the input level of A/D converter IC and the output level of sensors, each channel is configured to different gain, the input level of A/ D converter IC will get approximately equal level. Based on the characters of slow changing environment parameters, many channels can use the same sampling circuit with electronic switches that is controlled by MCU. Between the gaps of sampling, MCU reads the data of IC, then refreshes calendar and time. Many sets of display screen have been run for half a year. It shows that the stability and testing accuracy of this system are satisfied.