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本文阐述了基于Ⅱ网络零相位法石英晶体测量中改变激励电功率列石英晶体电参数的影响。主要以Ⅱ网络零相位法为测量方法,配以软件调节,硬件补偿等措施改变施加在石英晶体两端的激励功率,从而完成激励功率相关性的研究。重点阐述系统电阻校准方法和串联谐振电阻的测量。 相似文献
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基于直接传输法的石英晶体谐振电阻测量技术研究 总被引:1,自引:1,他引:0
在研究IEC444-5标准中的直接传输法的基础上,结合π网络零相位法中测量方法,提出了一种石英晶体谐振电阻测量的方法;该方法在测量过程引入了矢量电压,采用测量复阻抗方法来减弱π网络杂散的影响;在此基础上设计了石英晶体串联谐振参数测量系统,该系统采用DDS技术,有效提高了测量精度;实验结果表明,在1MHz~200 MHz频率范围内,石英晶体串联谐振电阻的测量误差不超过±10%(或±2Ω),满足石英晶体工业生产测量的需要. 相似文献
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傅冉舟 《自动化与信息工程》1997,18(4):14-15
本文介绍了专家系统在高精度温补晶振的计算机辅助制造中的实际应用,对今后人工智能在复杂因素条件下的计算机辅助制造有一定的启发作用。 相似文献
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李伟 《电子制作.电脑维护与应用》2014,(3)
本文介绍了8.192MHz石英晶体谐振器为例,说明了三次泛音电阻大于150Ω石英晶体谐振器的方法。利用条片具有泛音电阻大这一特点的同时,又结合圆片具有温度范围宽温度系数好的优点,在不改变整体设计结构的情况下,又能满足抑制泛音寄生频率的效果,给出了有效抑制石英谐振器三次泛音的设计公式和实测结果,增大三次泛音电阻可以有效抑制石英晶体谐振器的泛音振荡。 相似文献
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针对石油化工行业,尤其是油品的存储和交接过程中,精确测量温度的需求,论述了一种高精度手持式温度计的设计。该设计方案的感温元件使用Pt1000铂电阻和自主研发的嵌入式测量系统。详细讲解了温度计的测量原理和软硬件的设计方案,并给出了一种温度计环温补偿的软件算法。 相似文献
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高准确度宽温石英晶振热敏网络温度补偿 总被引:2,自引:1,他引:1
论述了热敏网络进行石英晶体温度补偿的基本方法,其中包括热敏电阻器的测量、非线性回归以及匹配算法,还介绍了补偿电路以及5种热敏网络的设计,并通过大量试验曲线讨论了在较宽温度范围内,当补偿准确度达到或超过1×10-6时应该考虑的各种因素。 相似文献
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介绍了一种供电阻传感器用的线性电桥电路的设计思想。该电路运用一只运算放大器实现非线性补偿,且补偿精度很高,有效地消除了电桥输出电压的非线性误差。 相似文献
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提出了一种可用于标准CMOS工艺下且具有二阶温度补偿电路的带隙基准源。所采用的PTAT2电流电路是利用了饱和区MOSFET的电流特性产生的,具有完全可以与标准CMOS工艺兼容的优点。针对在该工艺和电源电压下传统的启动电路难以启动的问题,引入了一个电阻,使其可以正常启动。基准核心电路中的共源共栅结构和串联BJT管有效地提高了电源抑制比,降低了温度系数。基于TSMC 0.35μm CMOS工艺运用HSPICE软件进行了仿真验证。仿真结果表明,在3.3V供电电压下,输出基准电压为1.2254V,温度系数为2.91×10-6V/℃,低频的电源抑制比高达96dB,启动时间为7μs。 相似文献
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D. K. BASU 《International journal of control》2013,86(4):393-399
A wide-range linear delay circuit is described. Such circuits have wide applications. The present circuit, which has excellent temperature stability, employs a compensated bootstrap circuit for generation of a linear ramp waveform and a regenerative Schmitt triggor comparator. The circuit provides good performance and sharp waveforms which may be used for triggering other digital circuits directly. 相似文献
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压阻式传感器热灵敏度漂移的变压源补偿 总被引:1,自引:1,他引:0
介绍了一种压阻式传感器灵敏度温度补偿的基本原理 ,并以加速度传感器为例 ,详细阐述了一种实用的变压源补偿电路。文章分析了整个温控电压源电路的温度特性 ,并给出补偿压阻系数的温度系数随温度变化的方法 相似文献
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This paper is aimed to carry out experimental verification of sensitive circuits of a quartz resonator applied in dew point recognition and it is proven at a microscopic level to be feasible in dew point recognition with great reliability and accuracy by using the high speed video. The sensor based on the sensitive circuits of a quartz resonator is composed of a quartz crystal and a Peltier module. Proactive approach is taken to produce condensation on the surface of the quartz crystal. The electrical parameters of the quartz crystal is changed due to dew condensation and then the resonant circuit stops oscillating. Initially, it needs to analyze the oscillation circuit and electrical characteristics of the quartz crystal, and then take photos of the surface of quartz electrodes with the high speed camera and microscope. Gray statistics is made for images of dew formation in its whole process. When the statistical results are analyzed in comparison to oscillation of the circuit, it shows that the time of the circuit oscillation stopping is roughly consistent with the time when moisture condensation occurs on the surface of the quartz electrode. And the time error of the two phenomena is less than 0.5 s, which is much less than response time of the platinum resistance sensor to the temperature. Furthermore, the results provide a strong theoretical basis for further measurement of the dew point temperature by this recognition method. 相似文献
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Inductor current sensing is very important in the control and monitoring of switching power converters. Traditional low cost implementation using a sensing resistor in series with the inductor will reduce the overall efficiency of the power converter. Conventional Hall effect current sensor could also be used to detect the inductor current. However, it will significantly increase the production cost of power converters. One simple and low cost implementation is to add a resistor–capacitor (RC) network in parallel with the inductor so that the inductor current can be derived from the added circuitry. The problem with RC sensing network is that the sensed variable is very sensitive to temperature variations. In this paper, a novel inductor current sensor using low cost negative temperature coefficient (NTC) thermistors to compensate the variation in the parasitic resistance of the inductor due to temperature changes is proposed. The changes in the cutoff frequency and steady state gain are also compensated by the added NTC thermistor circuit. With the compensated network, the sensed inductor current derived from the modified RC network will be independent of temperature variations. The compensated network can be applied to inductors fitted to power converters. Although experimental studies based on a buck converter were carried out to illustrate the correctness of the improved sensing technique, the proposed technique is applicable to other converter topologies. 相似文献
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三点式晶体振荡电路的起振特性与调节技术 总被引:3,自引:0,他引:3
根据一端口负阻抗分析法,并结合作者调节三点式晶体振荡电路的实践经验,分析了该类型电路的起振特性和起振条件,并提出了解决电路不起振等问题的一些基本经验和方法,从而为设计人员调节类似电路提供理论依据和技术支持。 相似文献
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