Dynamic Bridge Piezoelectric Amplifiers with Signal Generator

2012 ◽  
Vol 182-183 ◽  
pp. 374-377
Author(s):  
Hai Tao Xin
Keyword(s):  
Frequency Response ◽  
Piezoelectric Actuator ◽  
Power Supply ◽  
Dynamic Performance ◽  
Wide Frequency Range ◽  
Slew Rate ◽  
Frequency Range ◽  
High Demand ◽  
Positioning Accuracy ◽  
New Type

Piezoelectric amplifier is a very important part of the piezoelectric actuator. Not only positioning accuracy, but also dynamic performance and power are demanded more and more highly. At present piezoelectric amplifier are mainly used in static applications, power and frequency response are usually incompatible. This paper developed a new type of piezoelectric amplifier to meet high demand for dynamic, which takes dual-power supply, bridge-output to achieved slew rate, power were doubled, and maintain a wide frequency range at the same time. Controller implements DDS unit through FPGA, which could achieve sine, triangle, square and sawtooth.

Design and Analysis of Force Sensor for Condition Monitoring System of Ball Cold Heading Forming

2013 ◽  
Vol 364 ◽  
pp. 253-256 ◽  
Author(s):  
Qi Zhang ◽  
Ying Jun Li ◽  
Ru Jian Ma ◽  
Xiu Hua Men
Keyword(s):  
Condition Monitoring ◽  
Dynamic Performance ◽  
Force Sensor ◽  
Dynamic Measurement ◽  
Wide Frequency Range ◽  
Force Sensing ◽  
Frequency Range ◽  
Advantages And Disadvantages ◽  
Condition Monitoring System ◽  
Forming Defects

In order to solve the forming defects in the steel ball cold heading process, a novel force sensor which chooses the PVDF piezoelectric films as force-sensing elements is designed. The advantages and disadvantages of piezoelectric force sensor on measurement of the cold heading force are compared with existing force sensors. By using FEM, sensor’s linearity and the structure size are analyzed. Compared with the traditional sensor, this structure is more reasonable. The presented PVDF piezoelectric force sensor has wide frequency range, good dynamic performance, and can realize dynamic measurement.

Design of multi-layered bandpass filter with independently controllable triple-passband response

2014 ◽  
Vol 6 (6) ◽  
pp. 611-618 ◽  
Author(s):  
Yung-Wei Chen ◽  
Hung-Wei Wu ◽  
Yan-Kuin Su
Keyword(s):  
Frequency Response ◽  
Bandpass Filter ◽  
Bottom Layer ◽  
Wide Frequency Range ◽  
Electromagnetic Simulation ◽  
Frequency Range ◽  
High Isolation ◽  
Full Wave ◽  
Simulation Results ◽  
Good Agreement

In this paper, a new multi-layered triple-passband bandpass filter using embedded and stub-loaded stepped impedance resonators (SIRs) is proposed. The filter is designed to have triple-passband at 1.8, 2.4, and 3.5 GHz. The 1st and 2nd passbands (1.8/2.4 GHz) are simultaneously generated by controlling the impedance and length ratios of the embedded SIRs (on top layer). The 3rd passband (3.5 GHz) is generated by using the stub-loaded SIR (on bottom layer). Using the embedded SIR, the even modes can be tuned within very wide frequency range and without affecting the odd modes. Therefore, the design of multi-band filters with very close passbands can be easily achieved and having a high isolation between the passbands. The filter can provide the multi-path propagation to enhance the frequency response and achieving the compact circuit size. The measured results are in good agreement with the full-wave electromagnetic simulation results.

scholarly journals Systems mutual loadings of traction asynchronous cars

2019 ◽  
Vol 294 ◽  
pp. 05009
Author(s):  
Andriy Afanasov ◽  
Oleksandr Shapovalov ◽  
Maryna Voitenko
Keyword(s):  
Power Supply ◽  
Power Efficiency ◽  
Reactive Power ◽  
Capital Expenditure ◽  
Wide Frequency Range ◽  
Electrical Machines ◽  
Rolling Stock ◽  
Frequency Range ◽  
Wide Range ◽  
High Level

The review of methods of post-repair tests of traction asynchronous motors under conditions of locomotive depot is carried out.The necessity of introducing special stands for post-repair tests is shown in order to improve their quality, reduce the number of failures of service equipment, improve safety of the railway transport. Let’s consider a question of power supply of the research asynchronous engine in wide frequency range and also a possibility of creation of the universal stand for testing important asynchronous engines of the electrorolling stock. Survey of possible versions of the scheme mutual loadings of asynchronous electrical machines which can be used for testing traction asynchronous engines of the rolling stock is executed. Such systems can be constructed both with use of the static converter of frequency, and without it. The given short characteristic of each alternative, certain advantages and shortcomings of each of system options. It is shown that systems with use of static converters of frequency differ in high power efficiency, allow to carry out tests in the wide frequency range of power supply, however have higher prime cost. Schemes without converters of frequency differ in smaller power efficiency, impossibility to carry out tests in the wide range of frequency of power supply, high level of consumption of reactive power . The results of the carried-out analysis can be used when choosing rational option of a system mutual loadings of asynchronous electric motors which will differ in higher functionality and power efficiency. Use of such systems will allow to lower capital expenditure for creation new and modernization of traction electrical machines that exist at the station for test.

Mechanical, Acoustic and Electromagnetic Evaluation of the Semi-Implantable Middle Ear Hearing Device (SIMEHD)

1997 ◽  
Vol 76 (5) ◽  
pp. 321-327 ◽  
Author(s):  
Hassan A. Abbass ◽  
Michael Kane ◽  
Steven Garverick ◽  
Wen H. Ko ◽  
Anthony J. Maniglia ◽  
...  
Keyword(s):  
Frequency Response ◽  
Middle Ear ◽  
Electromagnetic Interference ◽  
High Frequency ◽  
Ossicular Chain ◽  
Wide Frequency Range ◽  
Frequency Range ◽  
Force Output ◽  
Margin Of Safety ◽  
Hearing Device

The properties of the partially implantable middle ear hearing device (SIMEHD) were extensively studied. The internal unit was subjected to 5,000 cycles of bending at a force of 75 g (gravity) without failure. An accurate measurement of the force output of the SIMEHD was obtained (14 - 25 dynes/mA). This force is too small to cause any damage to the ossicular chain. The force resulting from electromagnetic interference over a wide frequency range (500 Khz - 1 Giga (109) Hz) was measured and noted to be within the margin of safety. The frequency response plots (500 - 8,000 Hz) were also obtained and revealed an excellent ability to amplify middle and high-frequency sounds.

scholarly journals Self-Calibrated Measurement of Frequency Response for Broadband Photodetectors Based on Two-Tone Photonic Sampling

2021 ◽  
Vol 9 ◽  
Author(s):  
Mengke Wang ◽  
Ying Xu ◽  
Yutong He ◽  
Zhao Liu ◽  
Yali Zhang ◽  
...  
Keyword(s):  
Frequency Response ◽  
Wide Frequency Range ◽  
Repetition Frequency ◽  
Difference Frequency ◽  
Ultra Wideband ◽  
Center Frequency ◽  
Frequency Range ◽  
Frequency Responses ◽  
Tone Signal ◽  
Photonic Sampling

A self-calibrated method to measuring the frequency responses of broadband photodetectors (PDs) is proposed based on photonic pulse sampling of two-tone microwave signal, with the help of a mode-locked laser diode (MLLD) and a Mach-Zehnder modulator (MZM). Firstly, the repetition frequency of the optical comb from the MLLD divides the whole measuring frequency range into several segments. Then, a close-spaced two-tone signal modulates every comb tooth through the MZM and generates the sum- and difference-frequency products, working as the probing signal to extract the frequency response of the PD in every segment. Hyper-fine frequency response of the PD at any frequency point can be obtained in every segment by subtly varying the center frequency of the two-tone signal while keeping the difference frequency fixed. Finally, the whole frequency response of the PD in ultra-wide frequency range is obtained by seamlessly stitching the segmental frequency responses. In our experiment, measurement of a commercial PD is demonstrated up to 49.765 GHz with an optical comb at the repetition frequency of 9.953 GHz and a two-tone modulation up to 4.9765 GHz. The measured results are compared with those by using the traditional methods to check accuracy. Moreover, the uneven responses of the MLLD and the MZM are fully subtracted, verifying the ultra-wideband, hyperfine and self-calibrated measurement of PDs based on the two-tone photonic sampling.

scholarly journals Detection and localization of multiple small damages in beam

2021 ◽  
Vol 13 (1) ◽  
pp. 168781402098732
Author(s):  
Ayisha Nayyar ◽  
Ummul Baneen ◽  
Syed Abbas Zilqurnain Naqvi ◽  
Muhammad Ahsan
Keyword(s):  
Frequency Response ◽  
Natural Frequencies ◽  
Signal To Noise Ratio ◽  
Moving Average ◽  
A Priori ◽  
Damage Index ◽  
High Signal ◽  
Frequency Range ◽  
Spatial Locality ◽  
System Frequency

Localizing small damages often requires sensors be mounted in the proximity of damage to obtain high Signal-to-Noise Ratio in system frequency response to input excitation. The proximity requirement limits the applicability of existing schemes for low-severity damage detection as an estimate of damage location may not be known  a priori. In this work it is shown that spatial locality is not a fundamental impediment; multiple small damages can still be detected with high accuracy provided that the frequency range beyond the first five natural frequencies is utilized in the Frequency response functions (FRF) curvature method. The proposed method presented in this paper applies sensitivity analysis to systematically unearth frequency ranges capable of elevating damage index peak at correct damage locations. It is a baseline-free method that employs a smoothing polynomial to emulate reference curvatures for the undamaged structure. Numerical simulation of steel-beam shows that small multiple damages of severity as low as 5% can be reliably detected by including frequency range covering 5–10th natural frequencies. The efficacy of the scheme is also experimentally validated for the same beam. It is also found that a simple noise filtration scheme such as a Gaussian moving average filter can adequately remove false peaks from the damage index profile.

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