New Method to Characterize Magnetic Hysteresis in Soft Ferrites Up to High Frequencies

2006 ◽  
Vol 55 (1) ◽  
pp. 311-315 ◽  
Author(s):  
B. Tellini ◽  
R. Giannetti ◽  
G. Robles ◽  
S. Lizon-Martinez
Keyword(s):  
Magnetic Hysteresis ◽  
New Method ◽  
High Frequencies ◽  
Soft Ferrites

Externally Pressurized Bearings—II: Vibration Attenuators

1968 ◽  
Vol 90 (3) ◽  
pp. 614-617 ◽  
Author(s):  
D. F. Wilcock ◽  
W. E BeVier
Keyword(s):  
Frequency Response ◽  
Closed Loop ◽  
Magnetic Hysteresis ◽  
Rolling Element Bearings ◽  
High Frequencies ◽  
Gear Teeth ◽  
Hydrostatic Bearing ◽  
Performance Factors ◽  
Rolling Element ◽  
Turbine Blading

Rolling element bearings are vibration generators, and in addition are stiff, so that they transmit rotor generated noise as well to the machine frame and casing. Self-acting (hydrodynamic) bearings are also very rigid, so that they are excellent transmitters of rotor generated vibration, e.g., front gear teeth, turbine blading, or magnetic hysteresis. A typical rotor weighing 1000 lb may be supported on bearings having a stiffness of 3 × 106 lb/in., and hence will be a good vibration transmitter up to a frequency of 172 cps. Hydrostatic bearings afford an opportunity to control the bearing frequency response so that attenuation of middle and high frequencies can be secured. Analysis of the hydrostatic bearing as a closed-loop servomechanism reveals methods of designing them for attenuation without serious consequences in other performance factors. They may be used as the primary bearing, or as separate isolator bearings in conjunction with rolling element or self-acting bearings. Some examples of possible applications are discussed.

Development of a Non-Contact Precision Measurement Technique Using Optical Frequency Combs

2012 ◽  
Vol 523-524 ◽  
pp. 877-882 ◽  
Author(s):  
Taro Onoe ◽  
Satoru Takahashi ◽  
Kiyoshi Takamasu ◽  
Hirokazu Matsumoto
Keyword(s):  
High Resolution ◽  
Frequency Comb ◽  
High Sensitivity ◽  
Distance Measurement ◽  
New Method ◽  
Optical Frequency ◽  
Optical Frequency Combs ◽  
High Frequencies ◽  
Frequency Combs ◽  
Lock In

We develop a new method for high-resolution and contactless distance measurement based on self frequency beats of optical frequency combs. We use two optical frequency comb lasers with Rb-stabilized repetition frequencies for doing accurate distance measurement. The repetition frequencies of the optical frequency combs are different, thus parts of the high frequencies such as several gigahertz of self beats are beat-downed to several megahertz without an RF frequency oscillator. The phases of the beat signals of several megahertz frequencies are measured by a lock-in amplifier with a high resolution and high sensitivity. The new method is applied to distance measurement for objects which have rough-surface in the distance range of several-meters.

scholarly journals Amendment of the measurement of the equivalent series resistance at high frequencies

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Huimin Liu ◽  
Baoquan Ai ◽  
Fengguo Li
Keyword(s):  
Linear Relation ◽  
Large Deviation ◽  
Series Resistance ◽  
New Method ◽  
Equivalent Series Resistance ◽  
Low Frequencies ◽  
High Frequencies

A new method is proposed in (Ivković, Marković, Ivković, & Cvetanović, 2017) to measure the equivalent series resistance (ESR) and the inductance of a coil at low frequencies. However, a special phenomenon has appeared at high frequencies. It is found that the intercept has appeared and the measured inductance value had a large deviation from its nominal value. According to the analysis of result, an amended method is proposed in this paper. The inductance value should be amended according to the linear relation between the measured value and the nominal value.

Measurement and Modeling of Thermal Effects on Magnetic Hysteresis of Soft Ferrites

2007 ◽  
Vol 43 (11) ◽  
pp. 3952-3960 ◽  
Author(s):  
Hai Yan Lu ◽  
Jian Guo Zhu ◽  
S. Y. Ron Hui
Keyword(s):  
Thermal Effects ◽  
Magnetic Hysteresis ◽  
Soft Ferrites

scholarly journals APPLICATION OF MAGNETOELASTIC EFFECTS FOR STRESS ASSESMENT AND RISK MITIGATION IN CONSTRUCTIONS

2016 ◽  
Vol 21 (2) ◽  
Author(s):  
DOROTA JACKIEWICZ ◽  
MICHAL NOWICKI ◽  
ROMAN SZEWCZYK ◽  
ADAM BIENKOWSKI ◽  
MACIEJ KACHNIARZ ◽  
...  
Keyword(s):  
Natural Environment ◽  
Mechanical Load ◽  
Risk Mitigation ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Constructional Steel ◽  
New Method ◽  
Stress Assessment ◽  
Steel Truss ◽  
Magnetic Hysteresis Loops

<p>Stress assessment in the steel constructions is crucial for risk mitigation. NDT methods are widely used in such applications. However, many of these methods are hazardous, due to the radiation or chemicals used. The proposed magnetoelastic method is neutral to the natural environment. In this paper, development of such a method of stress assessment in constructional steel samples is presented. Measurements of the magnetic hysteresis loops of the sample members were performed under varying mechanical load on the specially designed steel truss test stand, which allowed to obtain magnetoelastic B<sub>m</sub>(σ)<sub>Hm</sub> characteristics. The results confirm the feasibility of the new method of NDT stress assessment in the steel truss constructions.</p>

Sign in / Sign up

Export Citation Format

Share Document