scholarly journals A High-Speed Current Source for Magnetorheological Application

2021 ◽  
Author(s):  
Xie Lei ◽  
Yuhao Wang ◽  
Chuan Lu ◽  
Zhipeng Yang ◽  
Changrong Liao
Keyword(s):  
High Speed ◽  
Response Times ◽  
Low Cost ◽  
Current Source ◽  
Buck Converter ◽  
Damping Force ◽  
Initial Current ◽  
Modeling And Experiments ◽  
Novel Strategy ◽  
Speed Response

Abstract Current source is an indispensable component of magnetorheological (MR) systems. Though MR fluid has a phase change as fast as in 1 ms, the response of MR damper (MRD) to generate the damping force may be two orders of magnitude longer. Therefore, the rapid response of current source is a key to realize the real-time semi-active control of MR devices. This study proposes a programmable high-speed, low-cost current source exclusively for MR devices based on the synergy between supercapacitor and Buck converter (i.e., SSBC current source). SSBC current source features a strategy consisting of a lifting phase of supercapacitor and a following maintaining phase of Buck converter. Specifically, the high power density of supercapacitor contributes to rapidly lifting/raising the initial current, and then, like a “relay race”, the expected output is maintained through a Buck converter. Theoretical modeling and experiments are performed systematically. The response times (@ 95% of expected outputs) measured are 0.44, 0.84 and 1.88 ms for the outputs of 3, 6 and 9 A, respectively; these values are highlighted as the fastest level in this field. Besides, the response can be up to 24.6 and 43.7 times faster than the cases using supercapacitor and Buck converter to directly drive the MRD, respectively. SSBC current source is employed to generate a sequence of currents/magnetic inductions, only four variables of which need to be controlled programmatically: the order of lifting and maintaining phases, switching time of lifting phase, PWM duty cycle of Buck converter and duration of maintaining phase. The response time stability is verified by 100 cycles of on/off tests, showing a fluctuation of only 1.1%, which indicates a very reliable high-speed response. This study provides an exclusive power supply with a novel strategy for MR devices, which is believed to be an important promotion for MR technologies.

Vibration Mitigation of Rotors Suspended on Low-Cost Hybrid Gas Foil Bearing

2019 ◽  
Author(s):  
Kamal Kumar Basumatary ◽  
Karuna Kalita ◽  
Sashindra K. Kakoty ◽  
Seamus D. Garvey
Keyword(s):  
High Speed ◽  
Low Cost ◽  
Current Source ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Electromagnetic Actuators ◽  
Manufacturing Method ◽  
Foil Bearings ◽  
Foil Bearing ◽  
Small Series

Abstract The hybrid Gas Foil Bearings combining the Gas Foil Bearing and Active Magnetic Bearing is a possibility for application in high-speed turbomachinery and a few developments have been made in this context. As such, the cost of conventional Gas Foil Bearing increases due to its requirement of precise manufacturing method and the coating material for the top foil and bump foil. In case of Active Magnetic Bearing, the normal electrical arrangement includes a multiplicity of independently controlled current sources usually at least four drives per bearing which increases its cost. Therefore, the hybrid Gas Foil Bearing will have much higher cost. In this work, a new electrical arrangement for the electromagnetic actuators of the hybrid Gas Foil Bearing has been proposed. The new arrangement requires only two drives per bearing and the bias current has been provided (in the same set of windings) through a simple rectifier with small series choke and shunt capacitor. As the number of drives required is less, the proposed bearing will have low cost. Implementing the new approach, the force vectors are achieved using only two current-source drives whereas the usual conventional arrangement requires four such drives. Numerical simulations are performed to explore the capabilities of the low cost bearing.

Front-End Circuit in Electrical Resistance Tomography (ERT) for Two-Phase Liquid and Gas Imaging

2014 ◽  
Vol 70 (3) ◽  
Author(s):  
F. R. Mohd Yunus ◽  
R. Abdul Rahim ◽  
Suzanna Ridzuan Aw ◽  
N. M. Nor Ayob ◽  
M. P. Jayasuman ◽  
...  
Keyword(s):  
Electrical Resistance ◽  
High Speed ◽  
Low Cost ◽  
Bubble Radius ◽  
Current Source ◽  
Electrical Resistance Tomography ◽  
Two Phase ◽  
2D Simulation ◽  
Phase Liquid ◽  
Frequency Changes

A steady and precise Voltage Control Current Source (VCCS ) with broad bandwidth plays a very important role in the quality of final images for the Electrical Resistance Tomography (ERT) system. Therefore, a model of current source is proposed in the paper which implement advanced Howland current pump as VCCS. The model are simulated through a software named multisim, and the simulation results show the proposed high-speed operational amplifier (op-amp) LM7171 is capable to produce constant output current at 10 mA (peak) when the frequency changes between 1 kHz to 500 kHz with load varies from 10 Ω to 1 kΩ. A two-dimensional (2D) simulation was performed using COMSOL and the results showed that the model is capable to detect air bubble (radius=10 mm) in a two-phase liquid and gas. The result presented with opposite excitation method with 150 kHz current at 10 mA. The measurement of boundary potentials are significantly influenced by bubble positions particularly towards the boundary. They are hoped to provide useful approaches for the design of practical and low-cost VCCS in ERT system.

Development and production experience of the multilayer curtain-coated linerboard of Ji’an PM No. 3,

TAPPI Journal ◽  
2014 ◽  
Vol 13 (2) ◽  
pp. 17-25
Author(s):  
JUNMING SHU ◽  
ARTHAS YANG ◽  
PEKKA SALMINEN ◽  
HENRI VAITTINEN
Keyword(s):  
Titanium Dioxide ◽  
High Speed ◽  
Food Packaging ◽  
Production Efficiency ◽  
Positive Impact ◽  
Low Cost ◽  
Board Structure ◽  
Flexographic Printing ◽  
Curtain Coating ◽  
Coating Formulations

The Ji’an PM No. 3 is the first linerboard machine in China to use multilayer curtain coating technology. Since successful startup at the end of 2011, further development has been carried out to optimize running conditions, coating formulations, and the base paper to provide a product with satisfactory quality and lower cost to manufacture. The key challenges include designing the base board structure for the desired mechanical strength, designing the surface properties for subsequent coating operations, optimizing the high-speed running of the curtain coater to enhance production efficiency, minimizing the amount of titanium dioxide in the coating color, and balancing the coated board properties to make them suitable for both offset and flexographic printing. The pilot and mill scale results show that curtain coating has a major positive impact on brightness, while smoothness is improved mainly by the blade coating and calendering conditions. Optimization of base board properties and the blade + curtain + blade concept has resulted in the successful use of 100% recycled fiber to produce base board. The optical, mechanical, and printability properties of the final coated board meet market requirements for both offset and flexographic printing. Machine runnability is excellent at the current speed of 1000 m/min, and titanium dioxide has been eliminated in the coating formulations without affecting the coating coverage. A significant improvement in the total cost of coated white liner production has been achieved, compared to the conventional concept of using virgin fiber in the top ply. Future development will focus on combining low cost with further quality improvements to make linerboard suitable for a wider range of end-use applications, including frozen-food packaging and folding boxboard.

Low-Cost High-Speed Techniques for Real-Time Simulation of Power Electronic Systems

2007 ◽  
Author(s):  
R. E. Crosbie ◽  
J. J. Zenor ◽  
R. Bednar ◽  
D. Word ◽  
N. G. Hingorani
Keyword(s):  
Real Time ◽  
High Speed ◽  
Low Cost ◽  
Electronic Systems ◽  
Power Electronic ◽  
Real Time Simulation ◽  
Time Simulation

High-speed electro-optic switch using buried electrode structure in polymer Mach–Zehnder waveguide

2016 ◽  
Vol 30 (06) ◽  
pp. 1650063 ◽  
Author(s):  
Jingwen Sun ◽  
Jian Sun ◽  
Yunji Yi ◽  
Lucheng Qv ◽  
Shiqi Sun ◽  
...  
Keyword(s):  
Insertion Loss ◽  
Rise Time ◽  
High Speed ◽  
Low Cost ◽  
Characteristic Parameters ◽  
Electrode Structure ◽  
Processing Cost ◽  
Electro Optic ◽  
Disperse Red 1 ◽  
Excellent Photostability

A low-cost and high-speed electro-optic (EO) switch using the guest–host EO material Disperse Red 1/Polymethyl Methacrylate (DR1/PMMA) was designed and fabricated. The DR1/PMMA material presented a low processing cost, an excellent photostability and a large EO coefficient of 13.1 pm/V. To improve the performance of the switch, the in-plane buried electrode structure was introduced in the polymer Mach–Zehnder waveguide to improve the poling and modulating efficiency. The characteristic parameters of the waveguide and the electrodes were carefully designed and the fabrication process was strictly controlled. Under 1550 nm, the insertion loss of the device was 12.7 dB. The measured switching rise time and fall time of the switch were 50.00 ns and 54.29 ns, respectively.

scholarly journals Towards a Glass New World: The Role of Ion-Exchange in Modern Technology

2021 ◽  
Vol 11 (10) ◽  
pp. 4610
Author(s):  
Simone Berneschi ◽  
Giancarlo C. Righini ◽  
Stefano Pelli
Keyword(s):  
Ion Exchange ◽  
Communication Networks ◽  
High Speed ◽  
High Performance ◽  
Low Cost ◽  
Modern Technology ◽  
Historical Background ◽  
Wide Range ◽  
Happy Marriage

Glasses, in their different forms and compositions, have special properties that are not found in other materials. The combination of transparency and hardness at room temperature, combined with a suitable mechanical strength and excellent chemical durability, makes this material indispensable for many applications in different technological fields (as, for instance, the optical fibres which constitute the physical carrier for high-speed communication networks as well as the transducer for a wide range of high-performance sensors). For its part, ion-exchange from molten salts is a well-established, low-cost technology capable of modifying the chemical-physical properties of glass. The synergy between ion-exchange and glass has always been a happy marriage, from its ancient historical background for the realisation of wonderful artefacts, to the discovery of novel and fascinating solutions for modern technology (e.g., integrated optics). Getting inspiration from some hot topics related to the application context of this technique, the goal of this critical review is to show how ion-exchange in glass, far from being an obsolete process, can still have an important impact in everyday life, both at a merely commercial level as well as at that of frontier research.

scholarly journals In-Plane Monolithic Integration of Scaled III-V Photonic Devices

2021 ◽  
Vol 11 (4) ◽  
pp. 1887
Author(s):  
Markus Scherrer ◽  
Noelia Vico Triviño ◽  
Svenja Mauthe ◽  
Preksha Tiwari ◽  
Heinz Schmid ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
High Speed ◽  
Low Cost ◽  
Photonic Devices ◽  
Monolithic Integration ◽  
Light Emitters ◽  
Fully Integrated ◽  
Large Lattice ◽  
Hybrid Iii ◽  
Gain Material

It is a long-standing goal to leverage silicon photonics through the combination of a low-cost advanced silicon platform with III-V-based active gain material. The monolithic integration of the III-V material is ultimately desirable for scalable integrated circuits but inherently challenging due to the large lattice and thermal mismatch with Si. Here, we briefly review different approaches to monolithic III-V integration while focusing on discussing the results achieved using an integration technique called template-assisted selective epitaxy (TASE), which provides some unique opportunities compared to existing state-of-the-art approaches. This method relies on the selective replacement of a prepatterned silicon structure with III-V material and thereby achieves the self-aligned in-plane monolithic integration of III-Vs on silicon. In our group, we have realized several embodiments of TASE for different applications; here, we will focus specifically on in-plane integrated photonic structures due to the ease with which these can be coupled to SOI waveguides and the inherent in-plane doping orientation, which is beneficial to waveguide-coupled architectures. In particular, we will discuss light emitters based on hybrid III-V/Si photonic crystal structures and high-speed InGaAs detectors, both covering the entire telecom wavelength spectral range. This opens a new path towards the realization of fully integrated, densely packed, and scalable photonic integrated circuits.

Based on FPGA Intelligent Physiological Parameters Acquisition

2013 ◽  
Vol 344 ◽  
pp. 107-110
Author(s):  
Shun Ren Hu ◽  
Ya Chen Gan ◽  
Ming Bao ◽  
Jing Wei Wang
Keyword(s):  
High Speed ◽  
Low Cost ◽  
Physiological Parameters ◽  
Sensor Data ◽  
Low Power Consumption ◽  
Physiological Signal ◽  
Pulse Sensor ◽  
Monitoring Applications ◽  
Field Programmable ◽  
Design Ideas

For the physiological signal monitoring applications, as a micro-controller based on field programmable gate array (FPGA) physiological parameters intelligent acquisition system is given, which has the advantages of low cost, high speed, low power consumption. FPGA is responsible for the completion of pulse sensor, the temperature sensor, acceleration sensor data acquisition and serial output and so on. Focuses on the design ideas and architecture of the various subsystems of the whole system, gives the internal FPGA circuit diagram of the entire system. The whole system is easy to implement and has a very good promotional value.

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