共查询到20条相似文献，搜索用时 125 毫秒
1.
可编程精密差动测量放大器 总被引：1，自引：0，他引：1
介绍了一种由DAC电压衰减器作为集成运放反馈电路的低噪声、低漂移、高输入阻抗和高共模抑制化的可编程精密差动测量放大器。LCD显示模块为控制提供友好的人机界面、实时显示放大倍数，并提供GAL可编程逻辑器件构成键盘编码器的方法。 相似文献
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数字程控放大器设计与应用 总被引：2，自引：0，他引：2
在自动控制系统或智能仪器中，如果测量信号的范围比较大，为保证必要的测量精度，经常采取改变量程的办法，当改变量程时测量放大器的增益也相应地加以改变，这种变化通常是自动进行，即不需要人为的改变电路连接，而是通过软件实现放大器增益的改变，这样可以实现仪器量程的自动切换，另外，通过改变增益的方法使系统功能增强，在核测量中，稳谱的方法之一就是改变输入信号的放大倍数，这就需要用到数字控制放大器，并针对核仪器要解决的具体问题要求放大器的放大倍数在一定范围内变化，并且放大倍数调节要求精细，该文提供了这种数控放大的一种设计方案，它的放大倍数范围为9－9．999，其倍数的调节步长为0．001倍。 相似文献
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王兰生 《水文地质工程地质》1982,(2)
声光水位仪是根据地下水具一定的导电特性,使之导通仪器电路,经放大后,触发声、光显示的原理制成。仪器外形见图1,其结构及电路图见图2。由水位触头,放大器,干簧管,声、光显示等组成。 相似文献
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《物探化探计算技术》2016,(3)
在长周期大地电磁测深仪中,探测的大地电场信号频率低、频带宽、能量弱、幅度小且易受环境噪声的影响。为了提高大地电场信号的测量精度,基于STM32微处理器,以TI公司的运算放大器和模数转换器相结合,搭建了由增益放大器、低通滤波器、差分驱动器、高精度Δ-∑A/D转换器和微处理器组成的一种长周期大地电场信号数据采集电路。测试表明,采集电路的主要技术指标满足电场信号采集要求。 相似文献
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介绍一种实用的多功能工程测振仪器的设计思想和实现方法，关重点分析了模拟放大器、信号自触发和高速Ａ／Ｄ转换器等部分电路的设计方案和工作过程。 相似文献
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在放射性测井中,伽玛射线通过探测器所输出的脉冲幅度一般为几十毫伏到一千多毫伏。要对这些信号进行处理,就必须先进行放大。这项工作由脉冲放大器来完成。 煤田放射性测井仪器对脉冲放大器的要求如下: 1.由于甄别器对脉冲幅度有一定要求,所以放大器应有足够大的放大倍数。 相似文献
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介绍了将集成运算放大顺输入端用电阻接地,组成开环放大电路,并用电容器输入电路隔开,成功地解决了同时接收交流或直流电压和流速仪接触信号。用施密特触发器组成脉冲展宽电路,并作分析计算。电路设计新颖、简洁。 相似文献
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高水测驗时,水深、流速大,容易冲断电线,妨碍测驗。以前曾有人試制过电子管单管測流放大器,但需要高压电路,且养护費用大,針对上述情况,我們用半导体試制放大器。这种放大器,經过一个多月努力,于5月30日試制成功,衡阳水文站进行試測,测到了近10米水深的洪峰。放大器只用了1.5伏的千 相似文献
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在复杂地质条件下进行钻探或处理事故时,常有需要增加钻压的情况。而所选钻机其所能产生的轴向压力是一定的。因此,在钻机选定后如何增加钻压的问题是个非常重要的问题,有时是一个非常急迫的问题。乌克兰国立矿业大学的专家们利用水力动力学原理研制出了一种新型钻压水动力增效装置,可以解决上述问题,值得借鉴。介绍了这种钻压水动力增效装置（ГУОН）的工作原理及其技术性能指标,并通过试验结果与理论计算结果进行了对比。 相似文献
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《Physics and Chemistry of the Earth, Part A: Solid Earth and Geodesy》1999,24(9):837-840
This paper describes a magnetotelluric (MT) survey carried out on the western edge of the Amiata geothermal region (Tuscany, Italy). In order to enhance the resolution of subsurface conductivity along the survey line and to define the deep features related to geothermal system heat recharge a continuous profiling method was used The standard wide-band MT data were collected at 28 sites, and 130 high frequency telluric-magnetotelluric (TMT) soundings were carried out at sites adjacent to the main wide-band sites. To tackle the problem of high electrical noise in the area the wide-band data were recorded simultaneously at two sites of the profile (local remote) and at a third far remote and electrically quiet site.Two-dimensional (2D) inversion of both TM and TM-TE data was performed, taking into account topographic and coast effects. The inversion results were able to define both shallow and deep resistivity anomalies whose structural significance is in good agreement with information derived from other geophysical data.Of particular geothermal interest is the evidence of a large conductive anomaly at a depth ranging between 2 and 4 km within the deep metamorphic basement. This anomaly could indicate the presence of a hitherto unidentified deep reservoir that is in communication with the reservoir exploited at present in the Amiata area. 相似文献
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在岩体土力学科研中,需要测定岩土在爆炸振动情况下的动力学参数,如加速度、速度、位移、压力等. 为了获得所需参数的测量,采用压电晶体加速度计作为传感元件,以测量爆破振动加速度.它有如下优点:体积小、灵敏度高、被测振动频率范围宽. 放大器要满足爆破测量要求,能适用于强烈爆破振动加速度测量是困难的,因为前置放大器不仅要有高输入阻抗,而且要耐震,能承受较高的瞬态冲击电压而不被击穿,并且传输 相似文献
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HOU Guiting QIAN Xianglin WANG Shuyuan SUN Jing Department of Geology Peking University Beijing 《《地质学报》英文版》2000,74(2):391-393
The ultra-long electromagnetic wave remote sensing technique developed by Peking University is one of new future techniques, which can detect the submarine geological information from the depth of 20 to 10000 m below the surface by receiving natural ultra-long electromagnetic waves (n Hz to n 100 Hz). The new remote sensor is composed of three parts: a main instrument with a portable computer, an antenna with an amplifier and an external power.The new remote sensing technique is characterized by good stability and reproducibility at the same spot but at different times and high sensitivity and high signal-to-noise ratio, and can reveal geological and lithologic boundaries as well as strata and related mineral sources. Two years of marine geological experiments on this technique have indicated that it can solve many problems in marine geological exploration, e.g. the burial depths of sea-floor mud, Quaternary sediments and submarine structures. This technique can be applied to detecting the sea bed depth 相似文献
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This paper describes a high input impedance preamplifier ,a main amplifier ,including its specification and the circuits theories .An acceleration measurement system consist of the piezoelectric acceleration 、preamplifier、cable 、main amplifier and oscilloscope for measureing the acceleration of vibration due to explosion .The features of the system are :1.good stability ,2.small zero shift ,3.The preamplifier is a new circuit which consists of four transistors 3DG6C,3DG4E. Its input impedance is as high as 1500MΩ and is able to undertake a high instantaneous impulse voltage ,4.There is no power supply set near the preamplifier .The signal transmiting cable is also the power supply cable so that the transmiting characteristic is very well .when the cable length is varied from 1 meter to 1000 meters ,the frequency response of system will not change .The decrement of output amplitude is less than 6% etc. 相似文献
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V. I. Korenbaum S. V. Gorovoy A. A. Tagiltsev A. E. Kostiv A. E. Borodin I. A. Pochekutova A. M. Vasilistov A. C. Krupenkov A. D. Shiryaev D. I. Vlasov 《Doklady Earth Sciences》2016,466(2):187-190
The problem of controlling the state and location of scuba divers is of importance. This work consider the possibility to use for this purpose a low-frequency noise of a scuba diver. The noise of a scuba diver under a dry swimming suite near the trachea and in the water at a distance of 50 m was recorded.It wa shown that both sygnals are characterized by the presence of quasi-periodic components induced by the amplitude modulation of wide-band breathing noises by the brething rhythms of a scuba diver. The quasi-periodic componentss distinguished can be used to evaluate the physiological parameters of the state of a scuba diver and to establish his location. 相似文献
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讨论了高阶Duffing型微分方程周期解的存在性,此类方程是二阶Duffing型方程的推广,具有重要的理论意义。利用同胚延拓和不动点方法,构造处理了一类比文献所述条件更弱的Duffing型方程。通过构造一个先验界,利用Schaud-er不动点方法得到解的存在性结论,所使用的方法能广泛适用于各种边界条件。 相似文献
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经典的油气差异聚集理论描述了油气在一系列不同盖层条件圈闭中的聚集现象:在盖层封闭性较好的圈闭序列中油气的聚集过程表现为差异聚集作用,在盖层不好的圈闭序列中油气的聚集过程表现为差异渗漏作用。当新生成的油气再次充注到老的油藏里时,将采用另外一种类型的差异聚集方式进行聚集——差异溶解作用。差异溶解作用的实质是油、气分子之间的溶解不平衡,其表现形式为新生成的油气在原有油藏里边溶解边聚集。差异溶解作用的结果是造成油气分布的复杂性,并呈规律性的变化:圈闭近源区充满干气或凝析气,远源区为油。 相似文献