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Wireless Power Transmission using inductive coupling, is one of the effective ways to transfer power between points without the use of conventional wire system. Wireless power transmissionis effective in areas where wire system is unreachable or impossible. The power is transferredusing inductive coupling, resonant induction or electromagnetic wave transmission depending on

whether its short range, mid-range or high range.The goal of this project Wireless power transmission mobile charger circuit using inductivecoupling is to charge a low power device using wireless power transmission. This is done usingcharging a resonant coil from AC and then transmitting subse uent power to the resistive load.The project is meant to charge a low power device uic!ly and efficiently byinductive coupling without the help of wires.

Block Diagram Explanation of Wireless Power Transmission Mobile Charger Circuit usingInducti e Coupling!

"ig# $ %loc! &iagram of Wireless Power Transmission 'obile Charger Circuit using (nductiveCoupling

(n this project, the wireless charger wor!s mainly on the principle ofinductive coupling . Withthis inductive coupling idea, we are trying to transfer power wirelessly to charge low powerdevices, such as mobile phones, cameras, wireless mouse etc.

"rom the bloc! diagram, it is clear that for the overall functioning of wireless charger circuit, itre uired a wireless power transmitter ) a wireless power receiver sections.

The transmitter coil in this wireless power transmitter section converts the &C power from anoscillator to a high fre uency AC power signal. This high fre uency alternating current, which islin!ed with the wireless power transmitting coil, would create an alternating magnetic field in thecoil due to induction, to transmit energy.

(n the wireless power receiver section, the receiver coils receives that energy as an inducedalternating voltage *due to induction+ in its coil and a rectifier in the wireless power receiversection converts that AC voltage to a &C voltage. "inally this rectified &C voltage would be feedto the load through a voltage controller section. That is, the wireless power receiver section smain function is to charge a low power battery through inductive coupling.

Working of Wireless Power Transmission Mobile Charger Circuit using Inducti eCoupling!

This project has mainly two sections, wireless power transmitter ) a wireless power receiversections. The Transmitter section of wireless charger circuit consists of a &C power source,oscillator and a transmitter coil. A constant &C voltage is provided by a &C power source, and

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this &C signal is the input to the oscillator circuit. This oscillator converts this &C voltage to ahigh fre uency AC power, and is supplied to the transmitting coil. &ue to this high fre uency ACcurrent, the transmitter coil energi es, and generates an alternating magnetic field in the coil.

DC power Source $ (t consists of a step down transformer that step downs the supply voltage to a

desired level, and a rectifier circuit to convert that AC voltage to &C signal.Oscillator Circuit: A modified Royer Oscillator circuit is used in our project. With this circuitwe can easily achieve a high oscillating current for the transmitter coil.

Theoscillator circuit used in the Wireless power transmitter section is given below.

"ig $ Transmitter section circuit

Wireless power transmitter section $/ere in the transmitter circuit section, we uses two 0channel enhancement power '12"3T *(4"567 8 9#,9 +,Two cho!es *:# ) : + , capacitor C*wor!s as a resonating capacitors+, diode &# ) & * provide cross coupled feedbac!+ , thetransmitter coil :*inductor+, resistors 4#,4 ,4; and 46 *wor!s as a biasing networ! for 9#)9 + etc. are used.

When power is given to the oscillator circuit, the &C current starts flowing through the two sidesof the coil *:#): + and also to the &rain terminals of the '12"3T. &uring the same instant,voltage appears on gate terminal of both the transistors and tries to turn 10 the transistors. Anyone of the transistor will be faster than the other and it will turn 10 first.

Assume that 9# will be turning on first, and then 9# s drain voltage will be clamped to nearground. At the same time, 9 will be in less conductive state or in off state, then 9 s drainvoltage will rise to pea! and starts to fall due to the tan! circuit formed by the capacitor C andthe primary coil of oscillator through one half cycle. The operating fre uency of the oscillator isdetermined by the resonance formula given below

" < = > ? > @ *:C+

0ote$ A /eat sin! is provided with each of the '12"3T to protect them from overheating andma!e them cool.

Transmitter Coil $ "or this Wireless power transmission mobile charger circuit usinginductivecoupling project, we can use mm enameled wire *'agnet wire+ for constructing the transmittercoils. Actually this enameled wire is a copper wire, which has a thin layer of insulation coatingson it. /ere the transmitter coil is constructed with a diameter of # .5cm or .5 inches and B.5 cmof length.

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The e uation for finding the inductance of a single layer air core coil is given below.

: < 7.77# 0 *a + *##6a D 56l+ /

0ow we are applying the desired values for the coil,

: < 7.77#> > *7.# 5 + **##6>7.# 5+ D * 56>7.7B5++ /

: < 7. E6 F/

Wireless power receiver section $ The receiver section consists of receiver coil, rectifier circuitand a voltage regulator (C. The AC current flowing through the transmitter coil creates amagnetic field. When we place the receiver coil with in a specific distance from this transmittercoil, the magnetic field in the transmitter coil eGtends to this receiver coil, and it induces an ACvoltage and generates a current flow in the receiver coil of the wireless charger. The rectifiercircuit in the receiver section converts this AC voltage in to &C and thevoltage regulator(C

helps to provide a constant limited regulated output voltage to the load for charging the low power devices. /ere we are using :' EB75 voltage regulator (C. (t is used because the (C givesa regulated 5H as its output and it don t allow more than 5H to the output.

The circuit diagram for 4eceiver section is given below.

"ig ; $ 4eceiver section circuit

The receiver coil in the wireless power receiver section is constructed using #B AWI copperwire having diameter of Bcm.The e uation for finding the inductance of a single layer air corecoil is given below.

: < 7.77# 0 *a + *##6a D 56l+ /

0ow we are applying the desired values for the coil,

: < 7.77#>; > *7.7B + **##6>7.7B+ D * 56>7.7#++ /

: < #. ;5 F/

The whole circuit section of our project is shown below.

8/18/2019 Wireless Power Transmission Using Inductive Coupling

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"ig 6 $ Wireless Power Transmission 'obile Charger Circuit using (nductive Coupling

Electronic Components!

Transmitter Section

• Holtage 2ource, Hdc$ ;7H

• Capacitors , C $ .B n"

• 4adio "re uency Cho!e,:#$ B. F/

• 4adio "re uency Cho!e, : $ B. F/

• Transmitter coil, :$ 7. E6 F/

Resistors:

• 4#$ #J

• 4 $ #7 J

• 4;$ K6 ohm

• 46$ K6 ohm

• 45$ #7 J

Diodes:

• &#$ &6#6B

• & $ &6#6B

Transistors:

• '12"3T, 9#$ (4"567

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• '12"3T, 9 $ (4"567

Receiver Section:

• &iode, &#, & , &;, &6$ &677E

• 4esistor, 4 #! ohm

• Holtage 4egulator (C$ (C :' EB75

• 4eceiver coil, :$ # . ;5 F/

Capacitors:

• C#$ .B n"

• C $ 7 F"<

"rom this Wireless power transmission mobile charger circuit using inductive couplingeGperiment, we conclude that wireless charging through inductive coupling is a better way forfuture energy transmission systems,that iswitricity *wireless electricity+ because with thistechnology we can transfer power wirelessly to charge electronic e uipment, vehicles, etc.

"ind the video related to wireless mobile charger,

"d antages of Wireless Power Transmission Mobile Charger!

• We can charge our mobile phone anywhere with this wireless mobile charger circuit.

• 0o need of separate mobile phone charger.

• 3asy to operate and it is environmentally friendly.

• &oes not need any wired charger.

Disad antages of Wireless Power Transmission Mobile Charger!

• :ow efficiency compared to the wired charging method.

• 3Gtra heating.

• The wireless mobile charging circuit is more complicated than the traditional charger.

• The cost is comparatively higher than the wired charger.

"pplications of Wireless Power Transmission Circuits!

•

Wireless Power Transmission Circuits can be used to charge camera batteries, mobile phones, wireless mouse, bluetooth headset etc.

• "uture development in this Wireless Power Transmission technology li!e witricity*wireless electricity+ will allow charging of car batteries, household e uipments, medicaldevices and other devices to charge wireless instead of wires.