共查询到18条相似文献,搜索用时 140 毫秒
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为了在光刻机投影物镜中使用压电陶瓷对像质补偿镜组进行精密定位,设计了一种以集成运算放大器构成的压电陶瓷驱动电路。针对光刻物镜中压电陶瓷的亚微米量级高精度定位要求,研究了驱动电路的系统精度要求,并对系统误差进行分解,着重分析了运算放大器放对系统精度的影响。首先,分析运放失调误差的影响;其次,使用PSpice仿真获得运放的固有频率特性,分析工作带宽下运放有限开环增益的影响;然后,对运放反馈网络的影响进行分析;最后,分析运放输出噪声的影响。计算表明,在最坏情况下该压电陶瓷驱动电路中由运算放大器引起的系统误差小于130mV,满足系统误差分配的要求。试制了系统样机并进行了验证实验,实验结果表明由运放引起的系统误差不超过100mV,与理论分析的结果符合。 相似文献
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针对压电能量源,提出了一种具有压电能量源极性判定的高效改进型单脉冲序列可配置能量收集接口电路芯片。该芯片通过采用同步电容开关接口电路,实现了在压电能量源内部电流源过零时的电荷再分享,将压电能量源内部电容上的电荷转移至外部电容,再通过开关控制,实现外部电容上的电荷翻转,最后将翻转后的电荷输送回压电能量源内部电容。该方法避免了压电能量源内部电容上存储的电荷被内部电流源过零后中和而造成的能量损失,实现了较高的能量俘获效率。通过采用0.18 μm标准CMOS工艺完成电路和版图设计,芯片版图有效面积仅需0.06 mm2。仿真结果显示:在压电能量源开路电压为2.8 V时,能够实现最高81.8%的电压翻转效率,与标准的全桥整流结构压电接口电路相比较,所提出的结构在能量俘获能力方面实现了最大8.1倍的提升。 相似文献
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压电传感器低频动态补偿数字滤波器设计 总被引:1,自引:0,他引:1
弹载压电传感器调理电路因测试环境的特殊性,难以采用精密的高输入阻抗电荷放大器.本文针对该问题设计了小体积的调理电路,并针对该测量电路因低频特性不足而导致的低频信号测量误差较大的问题,提出了动态实时补偿数字滤波器方法.运用CPLD器件实现了基于数字滤波器的实时动态误差校正,经实验验证,该补偿滤波器有效地延伸了压电传感器的低频测量范围,提高了弹载传感器的测量精度. 相似文献
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一种闭环E类放大器的分析与设计方法 总被引:2,自引:2,他引:0
开环E类放大器的设计一般通过理论计算得出电路中各元件的参数,然后固化成硬件电路,一旦电路负载发生变化,E类放大器不再继续工作于最优状态且输出功率不稳定。本文提出了一种基于负载变化的闭环E类放大器的设计方法,当电路负载变化时,不需改变原硬件电路,通过调整电路中晶体管开关激励电压的占空比和频率,使E类放大器继续工作于最优状态,通过调节输入电压使输出功率保持不变。本文最后以输出功率1W、初始负载电阻50Ω为例进行了设计和仿真,仿真结果与理论一致。 相似文献
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高压大功率变换器中如何降低半导体开关器件的电压应力是关键技术问题,而开关器件直接串联是重要的解决方案之一。在开关器件直接串联的高压电路中,开关器件的动、静态均压特性是关键指标。准有源栅极控制QAGC(quasi-active gate control)电路是具有代表性的串联均压拓扑,其特点是通过一个外部驱动源实现串联器件的动态、静态电压应力均衡,与此同时,可用于多个开关器件直接串联控制。研究表明,当QAGC驱动串联器件多于2个时,均压网络为上层器件提供的驱动电荷不足,降低串联器件的均压效果,严重时可能导致上层器件无法开通。针对这一问题研究了一种改进型QAGC电路,该电路将QAGC与一个辅助直流源相结合,辅助直流源在上层器件开通时刻提供额外驱动电荷,可保证器件的动、静态均压特性。分析了改进型QAGC的工作原理及设计方法,采用LTspice进行仿真并搭建实验平台进行验证,仿真和实验结果验证了电路拓扑的正确性。 相似文献
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《中国电机工程学报》2017,(6)
温度变化时聚合物材料内部的电荷输运特性或电极/介质界面处电荷注入的特性可能发生改变。因此,研究聚合物绝缘材料在高温下的空间电荷特性十分必要。该文采用新型的、具有高居里点的聚偏氟乙烯–三氟乙烯(polyvinylidene fluoride-trifluoroethylene,P(VDF-TrFE))薄膜作为压电传感器,分体设计了脉冲耦合电路、信号放大器电路和电极加热单元,建立了适用于室温~110℃的电声脉冲法(pulsed electro-acoustic method,PEA)空间电荷测量系统。从电声脉冲法测量空间电荷的原理出发,分析了对压电传感器输出的电压信号、最终空间电荷密度值的影响因素。计入了温度对试样中的声速和试样相对介电常数的影响,得出了温度影响空间电荷密度的幅值和位置的校正方法。利用该系统测量了纯环氧试样在不同温度下的空间电荷分布特性。 相似文献
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面向高性能轴承滚动体成型质量监控领域对重载多维高频强冲击载荷动态测量力传感器的急需,提出了一种基于PVDF压电薄膜三维重载力传感器新的结构形式及其测量原理,实现三维重载载荷动态测量。传感器敏感元件由上、中、下3层压电薄膜组组成,三维力变化引起每组不同面域切割的压电薄膜电荷量变化,从而实现三维力大小计算。传感器支撑壳体起到分载作用,从而实现重载载荷测量。对传感器样机进行了准静态标定实验,结果表明,该传感器具有较好的线性,非线性误差小于2%,能完成重载场合下的动态测量要求,为压电薄膜力传感器在重载多维载荷动态测量领域提供了重要的设计、研制及应用参考依据。 相似文献
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本文提出了一种新型的基于运算放大器的开关电容采样保持电路结构.采用速度补偿解决了高速高分辨采样保持电路对放大器要求增益高和速度快之间的矛盾.具体设计了采样保持电路.用Chart 0.35μmCMOS工艺,进行HSPICE仿真,结果表明,本文设计的采样保持电路的分辨率为10位,采样速率高于70MHz/S. 相似文献
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Kenji Uchino Jiehui Zheng Amod Joshi Yun-Han Chen Shoko Yoshikawa Seiji Hirose Sadayuki Takahashi J.W.C. de Vries 《Journal of Electroceramics》1998,2(1):33-40
Three techniques for measuring high voltage/power piezoelectric properties, which have been developed recently, are compared: a voltage-constant piezoelectric resonance method, a current-constant piezoelectric resonance method, and a pulse drive method. The conventional resonance method with a constant voltage circuit exhibits significant distortion (or a hysteresis) in the resonance frequency spectrum under a high vibration level due to large elastic non-linearity, which limits precise determination of the electromechanical coupling parameters. To the contrary, the resonance method with a constant current circuit (i.e., constant velocity) can determine the coupling parameters more precisely from a perfectly-symmetrical resonance spectrum. The general problem in both resonance methods is heat generation in the sample during the measurement. In order to separate the temperature characteristic from the non-linearity, it is recommended that the pulse method be used in parallel, even though the accuracy is not very high. 相似文献
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Markiewicz E. Kulek J. Pawlaczyk C. 《Dielectrics and Electrical Insulation, IEEE Transactions on》1999,6(3):304-308
A simple method is proposed to determine the parameters of a piezoelectric resonator equivalent circuit in the frequency range from 1 MHz to 1 GHz. Traditional methods use an electronic setup which always involves significant frequency range limitations. The present method overcomes this limitation by simultaneous measurement of the reflectivity coefficient of two samples with HP4191A RF impedance analyzer. The measurements are carried out on films of polyvinylidenefluoride (PVDF) and its copolymer (PVDF/trifluoroethylene (TRFE))(0.75/0.25) which were corona charged as well as corona charged and then thermally aged. Piezoelectric and elastic constants are calculated using the parameters of the piezoelectric resonator equivalent circuit 相似文献
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压电式振动能量采集的应用十分广泛,在许多能量采集装置中都采用压电元件实现能量转换。分析了振动能量采集装置中压电元件采集的能量输出管理电路,包括标准能量采集电路、DC-DC变换的优化标准能量采集电路、同步电荷提取电路、电感同步开关采集电路和双同步开关采集电路等五种电源管理电路的原理,比较了它们的能量采集输出效率,指出了各种电源管理电路的特点和适用条件。 相似文献
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W. E. Booij A. H. Vogl D. T. Wang F. Tyholdt N. P. Østbø H. Ræder K. Prume 《Journal of Electroceramics》2007,19(4):387-393
We have developed an analytical model for use in design and modelling of piezoelectric MEMS devices. The model allows for
incorporation of any number of device material layers in a multimorph structure including piezoelectric materials. The resulting
lumped circuit model fully incorporates the electro-mechanical coupling effects in the piezoelectric layers as well as electrical
or mechanical loading of the device structure. Since the model is analytic, and only requires the specification of well-defined
material properties, it allows for fast and interactive modelling of a multitude of MEMS device structures incorporating piezoelectric
materials. We will demonstrate the capability of the model by presenting results from fitting the model to impedance measurements
performed on cantilever structures. This allows for extraction of device and material parameters that are difficult to obtain
by other means, such as the piezoelectric coefficient and the mechanical quality factor. 相似文献
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Hoonbum Shin Varakorn Kasemsuwan Hyungkeun Ahn M. El Nokali Deuk-Young Han 《Journal of Electroceramics》2006,17(2-4):585-590
In this paper, the equivalent circuit model of a multilayer piezoelectric transformer (MPT) has been proposed and MPT has
also been fabricated using PMS-PZT to investigate the load and frequency characteristics. The model taking into account the
loss and the shift of resonant frequency due to the change of a stiffness caused from the lamination is developed based on
Mason’s equivalent circuit. The symbolic expressions were derived from the model. To verify the accuracy of the proposed equivalent
circuit model, MPT have been simulated. The simulation results have been compared with the experimental data. They are shown
to agree well over a wide range of various frequency and the load resistance. 相似文献
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基于虚拟仪器的无线脉搏检测仪设计 总被引:1,自引:1,他引:0
脉搏是人体生理特征的外在反映,对临床诊断有着重要的指导意义.通过压电传感器采集脉搏信号,设计硬件电路对脉搏信号进行调理和无线传输,结合虚拟仪器技术实现了脉搏波波形显示、存储、报警和特征值提取.对临床采集的10例高血压患者和10例正常人脉搏,利用支持向量机(SVM)的方法对提取的脉搏信号特征进行分类,实验表明,该方法可以... 相似文献