Analysis of dynamic-characteristic curve of tunnel diodes

1967 ◽  
Vol 3 (3) ◽  
pp. 114 ◽  
Author(s):  
T. Koryu Ishii
Keyword(s):  
Dynamic Characteristic ◽  
Characteristic Curve ◽  
Tunnel Diodes

Research on the Dynamic Loading Method of High Speed Spindle

2011 ◽  
Vol 103 ◽  
pp. 475-479
Author(s):  
Jie Meng
Keyword(s):  
Dynamic Characteristic ◽  
Dynamic Loading ◽  
High Speed ◽  
Characteristic Curve ◽  
Loading Method ◽  
Input And Output ◽  
Loading System ◽  
Loading Modes

This paper presents a method of dynamic loading on high speed spindle used dynamometer. Based on the range of speed and power, considering the performance of different high speed spindle, two loading modes are put forward. The loading system can measure input and output parameters and draw characteristic curve of high speed spindle at one time. These methods can be used to study the dynamic characteristic of the high speed spindle, whose states at different working points are obvious.

scholarly journals ANALYSIS OF THE DYNAMIC CHARACTERISTIC CURVE OF THE CAR POWER SUPPLY SYSTEM

2021 ◽  
pp. 87-96
Author(s):  
А.V. Puzakov ◽  
Keyword(s):  
Solar Cell ◽  
Dynamic Characteristic ◽  
Power Supply ◽  
Power Supply System ◽  
Characteristic Curve ◽  
Technical Condition ◽  
Supply System ◽  
Rotor Speed ◽  
Load Current ◽  
Loading Modes

Units of modern cars require an uninterrupted supply of electricity of the required quality, therefore, the prompt determination of the technical condition of the power supply system (SE) is an urgent task. During the operation of the car, there is a dynamic redistribution of electricity consumed for the needs of consumers between the car generator and the storage battery (AKB). The efficiency of the balance of electricity on board the car is influenced not only by the power of consumers, the mode of movement of the car, weather and climatic factors, but also by the technical condition of the generator and battery, however, insufficient attention has been paid to this. It has been established that the currents of the generator, the field winding and the battery, as well as the voltage of the on-board network, can serve as indicators of the technical condition of the vehicle’s ESS. The purpose of the article is to develop typical loading modes of a vehicle’s solar cell and a technique for their modeling in laboratory conditions. The leading method for solving this problem is fixing the ESS parameters using an analog data recorder with variations in the load current and the generator rotor speed. In the course of the experiment, the loading modes were changed in the order of increasing the generator rotor speed. The nature of the change in the parameters of the solar cell in the case of a working generator and a charged battery has been determined. The efficiency of the solar cell can be indirectly estimated by the ratio of the areas limited by the charging and discharging currents of the battery of the dynamic characteristic curve. With a load current of 10 A, the energy supplied by the battery generator exceeds the energy consumed for the work of consumers. When the load current increases to 15 A, the energy balance shifts towards the discharge part. The experimentally established dependences of the change in the parameters of the solar cell with variations in the load and speed modes of operation can be considered a scientific novelty. The practical significance of the research carried out is to increase the reliability of diagnosing SE based on the analysis of indicators of its technical condition. Further research will be aimed at determining changes in the parameters of the vehicle’s ESS in the process of occurrence and development of generator and battery malfunctions.

Study on dynamic characteristic and forging capacity of the direct drive press with symmetrical toggle booster mechanism driven by TPMLM

2021 ◽  
pp. 095440542199563
Author(s):  
Jingzhou Gao ◽  
Shengdun Zhao ◽  
Jingxiang Li ◽  
Wei Du ◽  
Yongfei Wang
Keyword(s):  
Dynamic Characteristic ◽  
Performance Optimization ◽  
Structural Parameters ◽  
Characteristic Curve ◽  
Research Work ◽  
Linear Motor ◽  
The Novel ◽  
Direct Drive ◽  
The Press ◽  
Permanent Magnet Linear Motor

Compared with the conventional servo press, the direct drive press even has no transmission mechanism, so it has advantages in controllability, precision and energy management. But, the forging capacity of the direct drive press is limited by the power of the linear motor. In this paper, a novel press driven by a tubular permanent magnet linear motor (TPMLM) is presented, and a symmetrical toggle booster mechanism is specially proposed to enhance the forging capacity. The mathematical model of the toggle booster mechanism is established, The TPMLM is designed, and the experimental prototype of the novel press is manufactured. The forging capacity and dynamic characteristics of the press are studied theoretically and experimentally. The results show that the introduction of the symmetrical toggle booster mechanism enriches the dynamic characteristic curve of the press and enhances the forging capacity. Therefore, the structural parameters of the toggle mechanism and the working position of the slider can be adjusted to meet different technological requirements. In addition, based on the research work, three directions are proposed to improve the forging capacity of the novel press. The research contributes to the performance optimization and development of direct drive press.

The Role of a Decision Rule in Symptomatic Pulmonary Embolism Patients with a Non-high Probability Ventilation-perfusion Scan

1997 ◽  
Vol 78 (02) ◽  
pp. 794-798 ◽  
Author(s):  
Bowine C Michel ◽  
Philomeen M M Kuijer ◽  
Joseph McDonnell ◽  
Edwin J R van Beek ◽  
Frans F H Rutten ◽  
...  
Keyword(s):  
Pulmonary Embolism ◽  
Decision Rule ◽  
Predictive Value ◽  
Patient Population ◽  
High Probability ◽  
Characteristic Curve ◽  
Stepwise Logistic Regression ◽  
Pulmonary Angiogram ◽  
Symptomatic Pulmonary Embolism ◽  
Perfusion Scan

Summary Background: In order to improve the use of information contained in the medical history and physical examination in patients with suspected pulmonary embolism and a non-high probability ventilation-perfusion scan, we assessed whether a simple, quantitative decision rule could be derived for the diagnosis or exclusion of pulmonary embolism. Methods: In 140 consecutive symptomatic patients with a non- high probability ventilation-perfusion scan and an interpretable pulmonary angiogram, various clinical and lung scan items were collected prospectively and analyzed by multivariate stepwise logistic regression analysis to identify the most informative combination of items. Results: The prevalence of proven pulmonary embolism in the patient population was 27.1%. A decision rule containing the presence of wheezing, previous deep venous thrombosis, recently developed or worsened cough, body temperature above 37° C and multiple defects on the perfusion scan was constructed. For the rule the area under the Receiver Operating Characteristic curve was larger than that of the prior probability of pulmonary embolism as assessed by the physician at presentation (0.76 versus 0.59; p = 0.0097). At the cut-off point with the maximal positive predictive value 2% of the patients scored positive, at the cut-off point with the maximal negative predictive value pulmonary embolism could be excluded in 16% of the patients. Conclusions: We derived a simple decision rule containing 5 easily interpretable variables for the patient population specified. The optimal use of the rule appears to be in the exclusion of pulmonary embolism. Prospective validation of this rule is indicated to confirm its clinical utility.

Analysis of magnetic force and dynamic characteristic for non-contact permanent magnet linear drive device

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1337-1345
Author(s):  
Chuan Zhao ◽  
Feng Sun ◽  
Junjie Jin ◽  
Mingwei Bo ◽  
Fangchao Xu ◽  
...  
Keyword(s):  
Finite Element ◽  
Permanent Magnet ◽  
Dynamic Characteristic ◽  
Driving Force ◽  
Magnetic Circuit ◽  
Response Speed ◽  
Computation Method ◽  
Element Analysis ◽  
Element Simulation ◽  
The Relationship

This paper proposes a computation method using the equivalent magnetic circuit to analyze the driving force for the non-contact permanent magnet linear drive system. In this device, the magnetic driving force is related to the rotation angle of driving wheels. The relationship is verified by finite element analysis and measuring experiments. The result of finite element simulation is in good agreement with the model established by the equivalent magnetic circuit. Then experiments of displacement control are carried out to test the dynamic characteristic of this system. The controller of the system adopts the combination control of displacement and angle. The results indicate that the system has good performance in steady-state error and response speed, while the maximum overshoot needs to be reduced.

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