Showing papers on "Magneto published in 1992"

Power supply circuit for an internal combustion engine

Abstract: The internal combustion engine has a battery and a magneto for an ignition system of the engine. The magneto has a charge coil and a source coil for generating a first alternating current and a second alternating current, respectively. The alternating current is rectified and the rectified current is supplied to the battery for charging. The second alternating current is supplied to electric loads to be operated by the engine.

Movement sensor for bicycle

Abstract: The utility model relates to a movement sensor for bicycles, which is composed of a magnetic field producing device and magneto sensitive elements. The state of the moving of the bicycle is changed into an electrical signal by the utility model. The movement sensor for bicycles is used for the cycle which uses ferromagnetic substance spokes. The magnetic field producing device and magneto sensitive elements are arranged on a cycle frame near the point of the spokes. The magnetic field producing device is a permanent magnet or the combination of the permanent magnet and a soft magnet core. The magneto sensitive elements comprise a coil, a hall element, etc. The entire sensor can be packaged into integration sensor.

Optical and mechanical design of magneto-optical disk heads

Abstract: Key factors in designing the optics, lens actuator, and head base for commercial magneto- optical heads are discussed in this paper. The design and performance of two types of magneto-optical disk heads developed at Mitsubishi are presented.

An Integral Equation Method for Analysis of Three-Dimensional Magneto-Dynamics with Moving Objects

Abstract: A three-dimensional calculation method for magneto-dynamics with moving objects has been developed. Its features are as follows: (1) An IEM approach, based on the integral expression of magnetic vector potential, is applied to calculate eddy current, magnetization and magnetic force. (2) Transient current in coils can be calculated by considering motion of the coils or magnetic substances. (3) An external circuit including a condenser, resistance or electric source can be considered. The method has been applied to the evaluation of dynamic characteristics of linear type voice coil motor and calculation results agreed weel with experimental data.

Analysis of Two-Dimensional Flows in Magneto-Dynamic Plasma Accelerators.

Abstract: The main focus of this dissertation is the study of ionized gas flows through magnetodynamic accelerators, also called MPD thrusters. The analysis is based on a one-fluid magneto-hydrodynamic model. The fundamental parameters considered here are the magnetic Reynolds number and the Hall parameter. This dissertation is focused on the regime of large magnetic Reynolds number. Two methods of analysis are considered in this study. First, a singular perturbation based on the small parameter E = 1/Rm. This singular perturbation leads to the formal separation of the problem into several sub-problems defined in different regions, and linked by a suitable asymptotic matching process. The outer problem is solved using a numerical simulation based on a Galerkin finite element method. Several inner-regions are also considered: the inlet acceleration layer, the magnetic boundary layer over an insulator, and the flow around a weak corner. The second method of analysis is a regular perturbation method based on the perturbation of a uniform flow by a small deformation of the boundaries, leading to a linear problem of fourth order. This problem can be solved by Fourier transformation. This method is used to find the inner solution near an isolated corner and to calculate the flow inside a weakly divergent thruster. These methods give qualitative results for the structure of the flow in the thrusters. The results underscore the importance of the Hall effect which is responsible for the existence of strong transverse gradients within the thruster. The analysis shows that the quasi one-dimensional model is inadequate when the inter-electrode distance is not large compared to the magnetic interaction length. In addition, it is shown that expansion fans obeying classical gas-dynamic laws on a small length scale, originate at the tip of the electrodes, and that the current lines refract across the expansion fan. In particular, near the anode tip, current lines refract away from the electrode surface. Thesis Supervisor: Manuel Martinez-Sanchez Title: Associate Professor of Aeronautics and Astronautics

Electric machine with permanent magnets

Abstract: The machine is designed for operation under hard dynamic modes at high maximal speeds. It consists of a rotating inductor, whose magnet poles are formed by the alternating polarity oriented permanent magnet poles with magnet axes tangentially oriented towards the axis of the machine shaft. Between the tangentially oriented magnets (2) magneto conductive inserts (7) are placed and permanent magnets (3) are adjoined to the inserts. These permanent magnets (3) have radially oriented magnetic axes with constant height and alternating polarity forming the outer cylindrical surface of the inductor. The radial magnets (3) for every pole pair are formed by a single segment magnet with local poles magnetized with two polarities. The segment magnets, when there are more then one, are axially dislocated one to another at one pole division. Instead of segmented magnets, ring magnets can be used with locally magnetized poles with alternating polarity.

Magneto-optic system of a large-acceptance channel for radioactive nuclei separation

Abstract: The results of calculation and design aspects of separating magnetic channel COMBAS of the tandem of cyclotrons U-400 and U-400M (JINR) are given. The requirements for the magnetic field distribution are formulated on the basis of analysis of nonlinear distortions in heavy-ion beam optics. Pole profiles of the magnets have been optimized using two-dimensional models. Numerical 3-D field simulation of the magnets has been carried out to provide the necessary fringe field distribution. >

Axisymmetric magneto-mechanical problem including ferromagnetic materials

Abstract: The computation of the displacements of ferromagnetics as a consequence of magnetic fields is presented. A method of calculation is presented, and the results are compared with measurements. The effect of a nonlinear material characteristic is examined. Its influence on the force distribution is estimated. It is shown that the magnetic forces within the material caused by the nonlinear characteristic are very small compared with the surface forces. The numerical results agree well with measurements made on a test bench. >

Additional rim type rare-earth magneto electric machine rotor

Abstract: The utility model relates to a rare-earth permanent-magnet motor rotor of an additional wheel net type, which is provided with a magnetic conducting core body manufactured by ferromagnetic materials, permanent magnets and a protecting ring. The utility model is characterized in that the magnetic conducting core body is a ring shape, wherein, the diameter of an inner hole of the magnetic conducting core body is matched with the outer diameter of a driven wheel. The outer part of the magnetic conducting core body is provided with a non-ferromagnetic barrier frame of a net shape, wherein, the non-ferromagnetic barrier frame of a net shape is provided with a groove and the permanent magnets manufactured by rare-earth permanent-magnet materials are embedded in the groove. The permanent magnets are arranged in pairs, and the magnetic conducting core body, the permanent magnets, the protecting ring and the barrier frame of a net shape are mutually fixedly connected. After the inner hole of the magnetic conducting core body is matched with the driven wheel, a permanent-magnet rotor integrated with a driven device is formed, a support mechanism of the rotor is saved, and the entire structure of the driven device is simplified.

Magneto-optical disk device

Abstract: PURPOSE:To reduce the total thickness of a magneto-optical disk device by using in common a permanent magnet for focus/tracking control of an objective lens and magnet for generation of the data recording/erasing external bias magnetic filed for the magneto-optical disk in a paired form and furthermore fixing these magnets independently of a carriage. CONSTITUTION:A carriage 9 movable in the radius direction of a magneto- optical disk 10 is provided together with an objective lens holder 2 which contains an objective lens 1, focus coil 4, a tracking coil 3, etc., and the magnets 5 nd 6 which are fixed independently of the carriage 9 so that the same magnetic poles are set counter to each other on a carriage shift path. Then the magnetic fields close to the same magnetic poles are used for the focus and tracking control purposes among those magnetic fields generated by both magnets 5 and 6. Meanwhile the optical axis direction component of the magnetic filed is used as a bias magnetic filed which decides the magnetic filed direction when the data are recorded and erased to the disk 10 at a position near the recording area of the disk 10. As a result, a thin and light-weight magneto-optical disk device is obtained.

Methods of magneto-inductive flow measurement and magneto-inductive flowmeters

Abstract: The invention relates to a magnetically inductive flow meter which generates a combined signal made up of a coil generated alternating voltage and an alternating simulated voltage. An evaluating circuit processes the combined signal to determine a flow rate output value in a manner which minimizes the temperature and time drift influences on the components of the flow meter.