Magnetic core

About: Magnetic core is a research topic. Over the lifetime, 30011 publications have been published within this topic receiving 155247 citations.

Gapped transformer design methodology and implementation for LLC resonant converters

Abstract: In the LLC resonant converter, the air gap is generally positioned in the core of the transformer for proper magnetizing inductance. Traditional transformer design methods assume infinite permeability of the core and no energy stored in the core. The improved design methodology for the gapped transformer is proposed with the optimum relative permeability and gap selection to meet the temperature rise and the magnetizing inductance requirements. The magnetizing current influences the magnetic flux in the core leading to the core saturation and core loss, while the resonant current contributes to the winding loss. The transformer design for a 200 W, 90 kHz LLC resonant converter is presented and experimental results validate the proposed methodology.

Process for making microcomponents integrated circuits

Abstract: A process for fabricating discrete electrical microcomponents, such as microtransformers, microautotransformers and microinductors, on a semiconductor substrate in which two patterned layers of electrically conductive material are electrically connected through vias in two interposed layers of electrically insulating material to form electrically conductive coils around a magnetic core formed by a patterned layer of magnetic material interposed between the two insulating layers. Laminated magnetic cores may be formed by patterning multiple layers of magnetic material. The microcomponents can also be formed without magnetic cores and can be formed on insulating substrates.

Discharge lamp lightening device

Abstract: Two fluorescent lamps are lightened by a single inverter circuit which provides switched power current to a single leakage transformer. The leakage transformer has a single primary winding coupled with said inverter circuit and a pair of secondary windings each coupled with a related fluorescent lamp. The core of said leakage transformer has a closed magnetic core with a pair of short legs each of which bridges across said closed magnetic path with a non-magnetic material so that said pair of short legs provides three windows and bypass leakage magnetic paths. The first window is defined by said pair of short legs, and each of the second and the third legs is defined by one of said short legs and said closed magnetic path. The primary winding is mounted in said first window, and each of said pair of secondary windings is mounted in said second or third window. The magnetic flux in said closed magnetic path provides high output voltage, which fires a lamp, then, the magnetic flux is switched to the leakage path which includes said short leg and the non-magnetic material, then, the output voltage is reduced but is enough to maintain the discharge current in the lamp.

Power control method based CT electricity getting device of high voltage transmission line

Abstract: The invention provides a power control method based CT electricity getting device of a high voltage transmission line, belonging to the field of high voltage technology. The high voltage transmission line successively penetrates through the middles of an electricity getting magnetic core and a measuring magnetic core; an electricity getting magnetic core coil and a measuring magnetic core coil are respectively positioned outside the electricity getting magnetic core and the measuring magnetic core; the electricity getting magnetic core coil is connected with an overvoltage protection and switching relay; the overvoltage protection and switching relay, a rectification filter circuit, a DC/DC module, a power management module and a voltage-stabilizing output circuit are connected; the rectification filter circuit is connected with a voltage-current detection circuit which is connected with the power management module; the power management module is connected with a farad capacitor whichis connected with the voltage-stabilizing output circuit; and the measuring magnetic core coil is connected with a sampling circuit which is connected with the power management module. The invention realizes that stable power is output within a larger current range and prevents the unsaturated situation of the magnetic cores when the current of the transmission line is large without heat-generating problems.

Optimal core dimensional ratios for minimizing winding loss in high-frequency gapped-inductor windings

Abstract: Numerical techniques are used to find the inductor core dimensional ratios that minimize winding loss. It is shown that common core shapes result in significant excess losses, even if the shape of the wire winding is optimized. A design example demonstrates the practical implications of this technique for choosing cores-a standard core with dimensional ratios close to optimum provides a 32 % savings in power loss compared to another popular core shape. Further improvements in power loss could be achieved by using optimized core shapes. Improvements to software for shape-optimization of windings are described, including accounting for different turn lengths at different radii, the ability to select gaps in different core legs, and better approximations of three-dimensional field geometry.