Inductor

About: Inductor is a research topic. Over the lifetime, 52565 publications have been published within this topic receiving 484068 citations. The topic is also known as: passive two terminal.

The Spherical Coil as an Inductor, Shield, or Antenna

Abstract: The spherical coil is an idealized form of inductor having, on a spherical surface, a single-layer winding of constant axial pitch. Its magnetic field inside is uniform and outside is that of a small coil or magnetic dipole. Its properties exemplify exactly some of the rules that are approximately applicable to practical inductors. Simple formulas are given for self-inductance, mutual inductance, coupling coefficient, effect of iron core, and radiation power factor in free space or sea water. This coil is the basis for evaluating the shielding effect of a closed conductive (nonmagnetic) metal shell. A special winding is described which enables simple and exact computation of self-resonance (the length of wire being just 1/2 wavelength in some cases).

Design method and material technologies for passives in printed circuit Board Embedded circuits

Abstract: The integration of passive components into the printed circuit board (PCB) as embedded passives integrated circuits (emPIC) results in a higher power density of power converters. To achieve a highly automated, low cost, integral manufacturing, the devices are constructed layer wise. Materials and processes necessary for the manufacturing of such circuits are described in this publication. Especially for magnetic components like inductors and transformers the design of such thin components is challenge. Because of the high aspect ratio, traditionally used models lead to a high calculation effort or use nonappropriate approximations. This contribution presents an analytic approach for the design. The model considers the magnetic flux distribution in the core and in the winding area and therefore allows a precise calculation of the inductivity as well as the losses in the device and their distribution. It is very well suited for a parametric analysis and thus for the synthesis of thin planar magnetic components. Material technologies for the construction of the capacitive layers and the magnetic cores are investigated. A ferrite polymer compound is adapted to be compatible with the PCB laminating process. Accordingly a 60-W offline converter was designed and fabricated using the new technology. Its transformer is entirely integrated in the PCB as well as 11 capacitors. Standard PCB lamination processes are used for the layerwise integration of the components. The circuit needs an area of the size of a credit card with a PCB thickness of 4 mm. Up to 82% efficiency could be demonstrated.

Design, Simulation and Applications of Inductors and Transformers for Si RF ICs

Abstract: List of Figures. List of Tables. Preface. Acknowledgments. Part I: Analysis and Simulation of Passive Devices. 1. Introduction. 2. Problem Description. 3. Previous Work. 4. Electromagnetic Formulation. 5. Inductance Calculations. 6. Calculation of Eddy Current Losses. 7. Asitic. 8. Experimental Study. Part II: Applications of Passive Devices. 9. Voltage Controlled Oscillators. 10. Distributed Amplifiers. 11. Conclusion. Appendices.

A novel low-loss modulation strategy for high-power bi-directional buck+boost converters

Abstract: A novel low-loss, constant-frequency, zero-voltage-switching (ZVS) modulation strategy for bi-directional, cascaded, buck-boost DC/DC converters, used in a hybrid electrical vehicle (HEV), is presented and its benefits over state-of-the-art converters and soft-switching solutions are discussed in a comparative evaluation. To obtain ZVS with the purposed modulation strategy, the buck+boost inductance is selected and the switches are gated in a way that the inductor current has a negative offset current at the beginning and the end of each pulse period. This allows the MOSFET switches to turn on when the anti-parallel body diode is conducting. As the novel modulation strategy is a software-only solution, there are no additional expenses for active or passive components compared to conventional modulation implementations. Furthermore, an analytical and simulation investigation predicts an excellent efficiency over the complete operating range and a higher power density for a multi-phase converter equipped with the low-loss modulation. Experimental measurements performed with a converter prototype verify the mode of operation and the ZVS principle.

Method and apparatus for sensing output inductor current in a dc-to-dc power converter

Abstract: A current sense circuit for a DC-to-DC power converter accurately senses the output inductor current without adversely affecting efficiency of the power converter. The current sense circuit produces a current sense signal having amplitude sufficiently above the noise floor so that accurate load control of the power converter is achieved. Specifically, the DC-to-DC power converter includes at least one power switch connected to an input voltage source. At least one phase sensing switch is connected to the input voltage source in parallel with the at least one power switch. A pulse width modulation circuit provides common control pulses for the at least one power switch and the at least one phase sensing switch responsive to a current sense signal. An output inductor is connected to the at least one power switch and to a load. A current sensor is coupled to the output inductor and providing the current sense signal to the pulse width modulation circuit corresponding to current passing through an internal DC resistance of the output inductor. The current sensor further includes a filter that includes an on-state resistance of the at least one power switch. The current sensor further includes a second filter adapted to remove noise from the current sense signal when the at least one phase sensing switch and the at least one power switch change state.