一种数字化总线式火灾探测器

介绍以微型单片机PIC16C54/56、串行A/D芯片LTC1297和离子烟雾传感器为基本部件,利用LTC1297的自动断电功能,组成数字化总线式火灾探测器的基本原理,结合实际应用,分析了串行A/D芯片可供选择的几种工作方式,并给出了试验结果,该探测器具有结构简单、耗电量小、测量精确和控制灵活等特点,适合远距离总线式数据采集系统的要求,大大地提高了火灾报警系统的可靠性,对设计各种类型的数字化总线式探测器具有实用参考价值。     

基于现场总线的矿井涌水量实时监测系统

为解决矿井涌水量实时监测问题,提出了流量与水位的综合转换法。利用该方法并结合现场总线技术开发出矿井涌水量实时监测系统,具体论述了系统的网络结构和软、硬件设计。实际运行表明该系统很好地满足了现场需要。     

DSP在交通测速雷达中的应用

介绍了DSP芯片TMS320VC5402的特性和在交通执法机构使用的测速雷达中的应用。利用雷达检测车辆运动产生的多普勒频率,在DSP芯片中利用现代谱估计的算法进行频谱分析得到多普勒频移。整个装置体积小、质量轻,可实现便携式测量。速度测量结果准确可靠。给出了系统的结构框图及DSP程序流程图。     

Prediction control of active power filters

A prediction method to obtain harmonic reference for active power filter is presented. It is a new use of the adaptive predictive filter based on FIR. The delay inherent in digital controller is successfully compensated by u-sing the proposed method, and the computing load is not very large compared with the conventional method. Moreover, no additional hardware is needed. Its DSP-based realization is also presented, which is characterized by time-variant rate sampling, quasi synchronous sampling, and synchronous operation among the line frequency, PWM generating and sampling in A/D unit. Synchronous operation releases the limitation on PWM modulation ratio and guarantees that the electrical noises resulting from the switching operation of IGBTs do not interfere with the sampled current. The simulation and experimental results verify the satisfactory performance of the proposed method.     

Fluorescence properties and application of doping complexes Eu1-xLx (TTA)3Phen as light conversion agents

Light conversion agents Eu1-x Lx (TTA)3 Phen (L denotes La3+ , Gd3+ , Y3+ ) complexes were prepared,and the influence of doping ions on fluorescence properties was investigated by elementary analysis, FTIR and fluorescent spectra. The results show that FTIR spectra of Eu1_x Lx (TTA)3 Phen complex system are identical with that of EuTTA3 Phen, which indicates that the complexes Eu1 xLx(TTA)3Phen are similar in structure to Eu (TTA)3Phen. For the above doping elements, co-fluorescence enhancement has the following order: Gd3+ ＞Y3+ ＞La3+ , and the optimum mole fractions of doping elements are 0.4, 0.2 and 0.5 respectively for Gd3+ , Y3+ ,La3+. Among all the complexes, Eu0.6 Gd0.4 (TTA)3 Phen complex has the strongest fluorescent intensity. Applying Eu0.6 Gd0.4 (TTA)3 Phen complex to plastic and printing inks, bright red fluorescence plastic and printing inks are obtained when the content of europium reaches 0.1% (mass fraction).     

电网电流检测系统的标度变换和单片机显示

本文提出了一种用霍尔传感器测量电网电流的方法主要说明其标度变换和单片机显示的过程。     

通风局扇变频控制系统

介绍了井下通风局扇的变频控制系统。该系统以变化的瓦斯浓度为参量 ,根据模糊控制规律 ,调整井下通风机的转速 ,可高效、安全地实现瓦斯的自动排放 ,节能效果明显。     

自动配料控制系统的研制

介绍了采用OMRONCPLC为主控机的自动配料控制系统 ,其可通过变频调速实现给料控制。该系统具有精度高、可行性好、抗干扰能力强等优点 ,有一定的推广价值。     

红外秒速耳温计设计中的关键技术问题

很多情况下，需要用红外耳温计迅速测量体温。文中介绍了红外耳温计的设计方法，在介绍其工作原理和软硬件设计的基础上，重点介绍了产品设计中关键技术问题的解决方法。按此方法设计出来的红外耳温计基本达到国外同类产品的水平。