Wireless driven led semiconductor lightning system
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This document discusses wireless power transfer technologies and their application to LED lighting systems. It begins with an introduction to wireless power transfer and wireless-driven LED systems. It then provides background on the history of wireless power by discussing Nikola Tesla's Tesla coil experiments. The document outlines four main methods of wireless power transfer: electromagnetic induction, capacitive coupling, resonant inductive coupling, and microwave transmission. It also discusses LEDs and their advantages for lighting. The document concludes that wireless power techniques have opportunities to make LED products more convenient and reliable compared to traditional wired systems.
![REFERENCE
[1] http://en.wikipedia.org/wiki/Tesla coil
[2] Liang Huang and Aiguo Patrick Hu, “An overview of capacitively
coupled power transfer—a new contactless power transfer solution”,
2013 IEEE 8th Conference on Industrial Electronics and
Applications(ICIEA), pp 461- 464.
[3] http://en.wikipedia.org/wiki/Microwave_transmission
[4] Vikash Choudhary and Satendar Pal Singh, “Wireless Power
Transmission: An Innovative Idea”, International Journal of
Educational Planning & Administration. ISSN 2249-3093 Volume 1,
Number 3 (2011), pp. 203-210 23](https://image.slidesharecdn.com/wirelessdrivenledsemiconductorlightningsystem-160617114937/85/Wireless-driven-led-semiconductor-lightning-system-23-320.jpg)
Wireless driven led semiconductor lightning system
- 1. WIRELESS DRIVEN LED SEMICONDUCTOR LIGHTNING SYSTEM MALAVIKA S S7 F ROLL NO-33 1
- 2. CONTENTS • Introduction • History of power transfer • Tesla coil • General principle and classification of wireless power transfer • Electromagnetic induction • Capacitive coupling • Types of capacitive coupling • Resonant inductive coupling • Microwave transmission • LED • Application • Conclusion • Reference 2
- 3. INTRODUCTION • Transmission of electrical energy from a power source to an electrical load without man-made conductors. • The wireless-driven led (wd-led) -combine the advantages of wireless electrical power transfer and led semiconductor lighting technology • Traditional led lighting system sensitive to rigid environment such as humidity, corrosive and flammable • The wireless-driven LED lighting system should contain LED lighting module, wireless electrical power transfer system, LED driving circuit and electrical energy storage system. 3
- 4. HISTORY OF POWER TRANSFER Tesla coil A Tesla coil is an electrical resonant transformer circuit invented by Nikola Tesla around 1891 It is used to produce high-voltage, low-current, high frequency alternating-current Tesla used his Tesla coil circuits to perform the first experiments in wireless power transmission at the turn of the 20th century 4
- 5. 0PERATION • The high electric field causes the air around the high voltage terminal to ionize and conduct electricity • Colorful corona discharge, brush discharge • A Tesla coil is a radio frequency oscillator that drives an air-core double-tuned resonant transformer to produce high voltages. • Uses simple spark gap 5 Fig 1:tesla coil in operation
- 6. CONT.. 6 Transformer(T): to step the AC mains voltage up to a high enough voltage to jump the spark gap(5 and 30kV). Capacitor (C1): with the primary winding L1 forms tuned circuit of the Tesla transformer Spark gap(SG) that acts as a switch in the primary circuit Tesla coil (L1, L2): an air-core double-tuned resonant transformer, which generates the high output voltage. Capacitive electrode(E): in the form of a smooth metal sphere or torus attached to the secondary. Its large surface area suppresses premature corona discharge and streamer arcs, increasing output voltage. Fig 2:spark excited tesla coil
- 7. GENERAL PRINCIPLE & CLASSIFICATION OF WPT 1.Electro magnetic induction • Known as inductive charging • The transmitter(L1) and receiver coils(L2) form a transformer . • AC through (L1) creates an oscillating magnetic field (B) by Ampere's law. • The magnetic field passes through (L2), where it induces an alternating EMF (voltage) by Faraday's law of induction,which creates an AC current in the receiver 7 Fig 3:electromagnetic induction
- 8. CONT.. • The power transferred increases with frequency and the mutual inductance M, which depends on the distance D between them • A widely-used figure of merit is the coupling coefficient(K) ,equal to the fraction of magnetic flux through L1 that passes through L2. • Safe way of connection, the products can be enclosed from air, water or plastic in the atmosphere. • The transmission power and efficiency will change if the distance between the two coils become closer or farther 8
- 9. 2.CAPACTIVE COUPLING • In capacitive coupling (electrostatic induction), power is transmitted by electric field between electrodes such as metal plates. • The transmitter and receiver electrodes form a capacitor, with the intervening space as the dielectric. 9 Fig 4 a)capacitive coupled power transfer b)simplified ckt
- 10. CONT.. • Voltage is applied to the transmitting plate, and the oscillating electric field induces an alternating potential on the receiver plate by electrostatic induction • Causes an alternating current to flow in the load circuit • The amount of power transferred increases with the frequency, capacitance between the plates, proportional to the area of the smaller plate and inversely proportional to the separation 10
- 11. CONT.. • Used for low power applications, because the very high voltages required to transmit significant power can be hazardous,cause side effects such as ozone production. • Electric fields interact strongly with most materials, including the human body, due to dielectric polarisation. • The field is largely confined between the capacitor plates ,reduces interferences • Alignment requirements between the transmitter and receiver are less critical 11
- 12. TYPES • Bipolar design:two transmitter plate two receiver plates. • Each transmitter plate is coupled to a receiver plate. • The transmitter oscillator drives the transmitter plates in opposite phase by a high alternating voltage • The alternating electric fields induce opposite phase alternating potentials in the receiver plates • This "push-pull" action causes current to flow back and forth between the plates through the load. • The two plates in the receiving device must be aligned face to face with the charger plates 12
- 13. • Unipolar design: the transmitter and receiver have only one active electrode, • Either ground or large inactive capacitive electrode serves as the return path for the current. • The transmitter oscillator and the load is connected between the electrodes and a ground connection, • Inducing an alternating potential on the nearby receiving electrode , causing alternating current to flow through the load and ground. 13
- 14. 3.RESONANT INDUCTIVE COUPLING • Resonant inductive coupling or electro dynamic induction • Wireless transmission of electrical energy between two magnetically coupled coils that are part of resonant circuits tuned to resonate at the same frequency. • An electrical component which consists of two coils wound on the same core with capacitors connected across the windings to make two coupled lc circuits 14
- 15. CONT.. • The two LC circuits are in different devices; • A transmitter coil in one device transmits electric power across an intervening space to a resonant receiver coil in another device • Because the coil is highly resonant,energy placed in the coil dies away relatively slowly , if a second coil is brought near it, the coil can pick up most of the energy before it is lost • The fields used are predominately non-radiative , near field hardware is kept well within the 1/4 wavelength distance they radiate little energy from the transmitter to infinity. • If two coils resonate with the same frequency, a lot of energy moves from the transmitting coil to the receiving coils 15
- 16. 4. MICROWAVE TRANSMISSION • Transmitting energy by the use of electromagnetic waves called microwaves • Frequency range (1ghz to 300ghz) • Wavelength (30cm down to 1cm) • Distance covered by microwave signal depends on antenna height. • To increase coverage each antenna has a built in repeater that regenerates that signal before passing it on to the next antenna • Antennas are placed for each 25miles • Microwave power transmission belongs to a long-distance power transmission technology. 16
- 17. • The cost for the practical installation of microwaves power transmission system is very high • Due to the working frequency or wavelengths, the power in the transmission will interfere with present communication systems. It relies on three key elements: 1.Use of radio frequency to achieve transmission 2.Clear line of sight with no obstacle in path way 3.Regular relay stations required due to line of sight and cost consideration 17
- 18. ADVANTAGE • Multiple channel • Large bandwidth DISADVANTAGE • Towers are expensive to build • Signal absorption by atmosphere • Line of sight will be disrupted by obstacles 18
- 19. LED • LED is a PN junction diode which emits light when forward biased • The amount of light output is directly proportional to forward current. • N-type layer is formed on a P-type substrate by a diffusion process. • Terminals from both layer make anode and cathode . • light energy is released at the junction when electrons and holes are recombined. • After recombination the electrons in the conduction band of N-region falls into the holes in the valance band of P-region . • The difference in energy between the conduction band and valance band is radiated in the form of light 19
- 20. • The semiconductor material used for manufacturing LED: Gallium arsenide-infrared radiation Gallium phosphide-red or yellow Gallium arsenide phosphide-red or green Gallium nitride-blue • Si and Ge is not used ,because they are heat producing materials 20
- 21. ADVANTAGE • Products are more convenient by eliminating the wires in the lighting system. • Safer and more reliable by eliminating the fire hazard and risk of short circuit with conductive interconnections, • Waterproof and explosion proof by removing the electric contacts and wires that connect led lighting module • More flexible by transferring electric power to LED lighting module through air, water, glass and plastic without any electric connection. • Improve the reliability • Electrical shock protection, • Portable and environmentally sound 21
- 22. CONCLUSION • Opportunities and challenges always go alone with the new technologies. • In many areas, the wireless power technique can be integrated with led lighting or display system, which can make led products more convenient or reliable compared to the traditional system • And with the commercialization of wireless-driven LED products, more and more related applications will be found. 22
- 23. REFERENCE [1] http://en.wikipedia.org/wiki/Tesla coil [2] Liang Huang and Aiguo Patrick Hu, “An overview of capacitively coupled power transfer—a new contactless power transfer solution”, 2013 IEEE 8th Conference on Industrial Electronics and Applications(ICIEA), pp 461- 464. [3] http://en.wikipedia.org/wiki/Microwave_transmission [4] Vikash Choudhary and Satendar Pal Singh, “Wireless Power Transmission: An Innovative Idea”, International Journal of Educational Planning & Administration. ISSN 2249-3093 Volume 1, Number 3 (2011), pp. 203-210 23
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