Showing papers on "Magneto published in 1993"

Coupled magneto-thermal field computation in three-phase gas insulated cables

Abstract: A numerical procedure employing the finite element technique is developed for the computation of the coupled magnetothermal field in three-phase gas insulated cables. The finite element formulation of both the electromagnetic and temperature field problems, the iterative procedure and the effective thermal conductivity of the insulation gas needed for the solution of the problem are presented here. Calculations made with the proposed method are presented in Part 2.

Auxiliary ignition system and method for aircraft engines

Abstract: An auxiliary ignition system comprising a first magneto having a normal operating mode and a start-up mode, and a second magneto having a normal operating mode and a start-up mode. A primary starter switch is operably wired to the first and second magnetos. Engagement of the primary starter switch activates the second magneto start-up mode and the first magneto start-up mode. Auxiliary ignition switches are operably connected to the primary starter switch wiring such that engagement of the auxiliary ignition switches after engagement of the starter switch causes the first and second magnetos to initiate engine ignition in their respective normal operating mode.

Electromagnetic center core dynamo

Abstract: A dynamo having an improved three piece stator system is disclosed. The dynamo stator system includes a physically continuous center winding located between two outer windings such that the configuration provides a strong series magnetic axis across the stator system to generate increased power output. The dynamo further includes a rotor system having a lateral offset mount which enables the rotor poles to rotate about the center winding. The dynamo further includes electrically coupling between the stator system elements to further increase the efficiency of the dynamo during operation and to reduce operational losses. In addition, magnetic insulation means is provided to insulate the rotor and stator elements. Brush means having a plurality of successive brush elements wherein each element has greater resistance than the previous element to further decrease operational losses is additionally provided.

Microprocessor-controlled inductive ignition system

Abstract: A microprocessor-controlled inductive ignition system uses a magneto inductive ignition circuit at engine starting speeds, and a microprocessor-controlled ignition circuit at engine running speeds. The microprocessor senses the ignition firings, computes the time between successive ignition firings, and disables the magneto inductive ignition system when the engine speed is greater than a predetermined cut-off speed. The ignition system enables an engine with a recoil starter to be started if the battery is low or if an alternator is used to power the microprocessor. At engine running speeds, the ignition system achieves a greater amount of timing advance than achievable with an inductive ignition system alone, thereby increasing engine efficiency.

The Present Status of Magneto-Optic Eddy Current Imaging Technology

Abstract: This paper provides a description of the basic working principles underlying a new kind of eddy current-based inspection technology called magneto-optic/eddy current imaging [1–4]. By combining magneto-optic imaging and eddy current excitation in an unconventional manner, it is now possible to obtain real-time eddy current images of fatigue cracks and areas of hidden corrosion in structures such as the fuselage of an aging aircraft. The paper begins with a description of working principles, then turns to specific examples of inspections performed on representative samples of commonly encountered airframe components, areas for potential improvement of the technology, and finally, new applications.

Combination low oil indicator and kill switch for internal combustion magneto driven engine

Abstract: An electrical switch has three terminals, one that is always connected to one side of an LED and in parallel to a resistor. A rocker slides a movable contact to and from an engine OFF or kill position, from and to an engine RUN position. An oil detector circuit uses the engines magneto system to light the LED when the switch is in the RUN position and the engine is rotated. The flashing LED provides a visual indication of low oil in the engine.

An Analysis of Nonreciprocal Phase Characteristics of Magneto-Optic Channel Waveguides Using Finite-Element Method

Abstract: To evaluate nonreciprocal phase characteristics of a magneto-optic channel waveguide, the formulation of a finite-element method based on a scalar wave approximation is discussed here for the first time. This problem is ascribed to the problem of solving a nonlinear eigenvalue equation. However, a simple iterative method is proposed here for solving the nonlinear eigenvalue equation. The validity and usefulness of the present method are demonstrated in analyzing magneto-optic rib waveguides and magneto-optic ridge waveguides. A discussion to increase a nonreciprocal phase shift in those waveguides also is given.

A magneto-optic crystal based current measurement device

Abstract: This paper describes the development and testing of an optical crystal based current sensor for use on medium and high voltage power networks. The sensor uses a terbium gallium garnet (TGG) magneto-optic crystal and is of an unlinked nature, with the sensing head consisting entirely of dielectric materials. Testing is reported at voltage levels up to 300 kV and current levels of 75 kA. A vibration compensation scheme and microprocessor based relay interface are described and temperature problems are discussed.

Single-phase brushfree neodymium iron boron ac generator

Abstract: The utility model relates to a magneto alternator. A pair of additional magnetic poles is added on a rotor of a motor; meanwhile, a group of transverse axis coils are arranged on a stator. Proper capacitors are connected in series with the transverse axis coils which can generate advanced electric currents. When load electric currents are augmented, total magnetic flux is increased, and thereby, the characteristic of the output voltage is improved to satisfy the used requirement. The magneto alternator has the advantages of simple structure, no slide rings or electric brushes, no need of a direct current excitation power supply, high efficiency, high reliability and low temperature rise. The technology is also applicable to a three-phase magneto alternator.

Magneto-sensitive optical rotary glass and its preparation method

Abstract: This invention relates to a magneto-sensitive optical glass with high Flood constant (0.26-0.38, wavelength of 632.8 nm), which features that Tb2O3-Al2O3-B2O3SiO2 series magneto-optical glass and secondary smelting are used. The product may be used in visible light and near-infrared band and has excellent drawing performance.

Method for continuously casting steel using magneto static field conducting method

Abstract: PURPOSE:To prevent the deterioration of the quality caused by the deep intrusion of bubbles and inclusions into molten steel. CONSTITUTION:In a continuous casting of the molten steel 6 by using a multi- hole nozzle 2 having two or more of discharging holes 7 at the side wall of the lower part, to both end parts in the width direction of a cast slab 5 at the lower part from the discharging holes 7 of the nozzle, static magnetic field conduction is executed by impressing the magnetostatic field in the crossing direction at the right angle to the long side surfaces of the cast slab 5 and at the same time, by impressing DC current in the crossing direction at the right angle to the short side surface of the cast slab 5 to execute the continuous casting. By this method, the internal defect and the surface defect of the cast slab 5 can remarkably be reduced.

External magnetic field applying device for magneto-optical disk

Abstract: PURPOSE:To provide an external magnet field applying device of a magneto- optical disk in which a magnetic field reversing speed at the time of recording applied to a magneto-optical disk is increased and the power consumption is reduced. CONSTITUTION:Switching transistors Q1 and Q2 are connected to a first and a second electromagnetic coils L1 and L2 which are wound in an opposite direction to each other. Control signals S1 and S2 corresponding to recording information are supplied to the control electrodes of the transistors Q1 and Q2 so as to apply the magnetic field, whose opposite polarities are reversing, to the magneto-optical disk.