report 2nd review

8/7/2019 report 2nd review

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CONTACTLESS POWER TRANSFER SYSTEM

A PROJECT REPORT

Submitted by

A. MOHAMMED HUSSAIN

S. NARENDRAN

SYED ADIL BAHAMANI

in partial fulfillment for the award of the degree

Of

BACHELOR OF ENGINEERING

in

ELECTRONICS AND COMMUNICATION ENGINEERING

TAGORE ENGINEERING COLLEGE

ANNA UNIVERSITY: CHENNAI 600 025

MAY 2011


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ABSTRACT:

This paper proposes a model of Contactless Power Transfer system

(CPTS), which adopts transformer with big air-gap and primary and

secondary coils. The system has the characteristics of long leakage

inductance, small magnetizing inductance and low coupling coefficient.

This makes the transmission efficiency very low, this model improves the

system efficiency by adopting resonance of compensation capacitance

and leakage inductance in transferring energy to the load. Thus the main

objective of the project is to transfer the power without any contact.

Keyword Contactless Power Transfer System (CPTS)


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CHAPTER 1

INTRODUCTION

1.1 INDUCTIVE POWER SUPPLY

Inductive Power Supply is a new technology which is advantageous incomparison to current-rails, cables and battery supply systems. The advantages of this new

developed technology are based on maintenance-free operation, no sparkling effects due to

contact problems, complete isolation of primary and secondary conductors and ruggedness

against dust and environmental conditions.

The inductive power supply is based on the principle of basic transformer,

which consists of a primary windings and secondary windings. But the only difference when

compared to transformer is these two windings are separated over a distance.

In normal transformer the power is transformed in frequency ranging 50-60

Hz, but this power frequency is not enough to transfer the power over a distance betweenprimary and secondary coils. So we need to increase the power frequency in the range of

KHz to achieve this power transfer.

This inductive power technology can be used for transport purposes like cars, buses,

trains as mentioned. Implementing and maintenance is easy and simple. Accessing of

multiple devices and vehicles are possible since the secondary coil is placed inside the each

vehicle so it gets the power from one primary winding.

The basis for this new developed technology is the use of a primary coil and

secondary coil, but the secondary coil is located on the moving transportation system

inductively coupled to a primary winding which is located and fixed along the track of the

transportation system.

There are a number of technical criteria to be solved to make this contactless

inductive power supply working with high efficiency and to become an economically power

supply system.


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The use of high frequency leads to acceptable dimensions of the active secondary

coil. The distributed winding on the primary leads to a large impedance and therefore

corresponding apparent power is required. The effect of specific compensating technologies

is that only real power has to be supplied by the high frequency power supply on the primary.

In addition special attention has to be given to the design of the secondary coil

arrangement to provide the magnetization of the air gap between primary winding and

secondary coil. The different design aspects of contact-less inductive power supply will be

presented.


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CHAPTER 2

CONTACTLESS POWER TRANSFER

2.1 PRINCIPLE OF OPERATION

IPT is a contactless power transfer system that allows electrical energy to be supplied

to mobile equipment without any mechanical contact. Each system is comprised of two parts,the primary and secondary. These are magnetically coupled, similar to a conventional

transformer.

The primary consists of a track power supply and track cable along the path of

electrification. The pickups and pickup regulators form the secondary. Unlike a conventional

transformer, where primary and secondary are tightly coupled, IPT is a loosely coupled

system. With higher operating frequencies (10 kHz to 25 kHz, power may be transferred

across air gaps of up to several centimeters.

2.2 BASIC BLOCK DIAGRAM

Here the system works based on the principle of transformer Power supply given to

the primary coil is at high freq which is in the range of kHz. But in this system there is a big

air gap between primary and secondary coils.

M

M

Microcontroller

(pwm)

Cptsprimary section

Hu

Cpts

Secondary section

Load


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Hence power supply given to the primary coil is at high freq which is in the range of

kHz. The primary coil links the secondary coil through the magnetic flux of lines due to the

high freq oscillations. The primary coil links the secondary coil through the magnetic flux of

lines as shown in Figure 2.1 due to the high freq oscillations .Thus it makes to induce current

in secondary coil that is given to load.

2.3 MAIN BLOCK DIAGRAM OF CPTS

The primary section and secondary section blocks are elaborated in the below shown

Figure 2.2.The primary section consist of microcontroller, MOSFET, and resonant converter

and the secondary section consist of inductor, rectifier, filter capacitor ,boost converter

,voltage regulator, battery charger, sensor and motor.

Magnetic Couplingacross air gap

(PWM )

microcontroller

Boostconvert

MOSFET

Secondary

Induct

Resonant

Rectifier

Filter

Capacit

Voltage

TrainMoto

Batter

y


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CHAPTER 3

CPTS PRIMARY SECTION

3.1 BLOCKS OF PRIMARY SECTION

The primary section has three main blocks

1. Microcontroller(Pulse Width Modulation)

2. MOSFET

3. Resonant converter

3.2 Microcontroller Advanced Kit - Pulse Width Modulation

It is easy to use a microcontroller to turn LEDs ON and OFF . But you can only turn

the LED ON and OFF. So what if you want to control the brightness of the LED? The same

problem comes up in robotics where you want to control the speed of a motor with a

microcontroller. It is not good enough to just turn the motor ON and OFF. To control the

brightness of the LED or speed of the motor you have to control the amount of current going

through the device. But how? One solution that may occur to you is to quickly turn the LED

or motor ON and OFF. The current only flows when the output is low (for microcontrollers

LED circuits are usually wired so current flows into the microcontroller when the output is

low, as shown in the tutorial at http://www.iguanalabs.com/1st2051.htm). The output of your

microcontroller will look like the following square wave as in Figure 3.2.1.

Figure 3.2.1 Output of Microcontroller


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If you turn an LED or motor ON and OFF fast enough then it will appear to stay on

continuously and since there is less current flowing overall the LED will appear less bright

and the motor will run at a slower speed. With this solution you can make the LED flash ON

and OFF as slow as 30 times a second but any slower and you start to see the LED blinking

which is not the desired result. Or, for the motor, it will lose its smooth operation and get

jerky. The solution does not work very well because the LED is still rather bright at 30 times

a second.

We are on the right track but rather than changing the number of times the output

goes ON and OFF, we change how long the output stays ON and OFF. Let's take a closer

look at one output cycle. An output cycle consists of a low period, tlow and a high period,

thigh. tlow + thigh = T, where T is the period (length of time) for one output cycle as in

Figure 3.2.2. thigh is also called an output pulse, or just pulse.

Figure 3.2.2 One Output Cycle

We will always keep T the same so that there is always the same number of output

cycles per second. If we increase the width of thigh then we must decrease tlow to keep T the

same. If we decrease thigh then we must increase tlow. For the case that we make thigh smallthen the output looks as Figure 3.2.3 .


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For the case that we make thigh large then the output looks like the following Figure

3.2.4.

Figure 3.2.4 LED is OFF for Long Time

The output is Vcc most of the time which turns off the LED. The current only flows

through the LED for the brief time that the LED is on during tlow. But since we are still

turning the LED on and off very fast (we will use about 100 times a second in the examples

below), you cannot see the LED blinking and it appears very dim. The total current that flows

through the LED is low. For the motor it will smoothly turn at a low speed. So we can

control the brightness of the LED or the speed of a motor by changing the width of thigh.

This is the secret of Pulse Width Modulation.

3.2.1 HOW IT WORK WITH MICROCONTROLLER

Next we will see how to make this work in an 8051. We can use the hardware setup as

shown in either the first microcontroller project for the 8051. The software examples work

for either of the hardware setups..

In the first This we uses two delay routines. One delay is used to control tlow and theother delay is used to control thigh. The example is set to minimize tlow and maximize thigh

to make the LED appear very dim. To make the LED brighter you can decrease R4 and

increase R3. This example works fine and shows an easy way to control the pulse width. The

biggest disadvantage is that it assumes you will be not be doing anything else in your

program. If you try to do some other processing you will affect the timing of the pulses.


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3.5 CIRCUIT DIAGRAM OF CPTS PRIMARY SIDE

The circuit diagram of the Power Transfer primary section is shown in the figure 3.5

below

In the above circuit diagram the microcontroller used is AT89c51 where two NOT gate

741s14 act as a driver , and two MOSFET drivers are used to control the MOSFET which is used

for speed switching. And the features and description of each component in primary side is

elaborated below.


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3.5.1 8-BIT MICROCONTROLLER (AT89C51)

Features

Compatible with MCS-51 Products

4K Bytes of In-System Reprogrammable Flash Memory

Endurance: 1,000 Write/Erase Cycles

Fully Static Operation: 0 Hz to 24 MHz

Three-level Program Memory Lock

128 x 8-bit Internal RAM

32 Programmable I/O Lines

Two 16-bit Timer/Counters

Six Interrupt Sources Programmable Serial Channel

Description

The AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with

4Kbytes of Flash programmable and erasable read only memory (PEROM). The device is

manufactured using Atmels high-density nonvolatile memory technology and is compatible with

the industry-standard MCS-51 instruction set and pinout. The on-chip Flash allows the program

memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer.

By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C51 is a

powerful microcomputer which provides a highly-flexible and cost-effective solution to many

embedded control applications. The AT89C51 provides the following standard features: 4K

bytes of Flash, 128 bytes of RAM, 32 I/O lines, two 16-bit timer/counters, a five vector two-level

interrupt architecture, a full duplex serial port, on-chip oscillator and clock circuitry. In addition,

the AT89C51 is designed with static logic for operation down to zero frequency and supportstwo software selectable power saving modes. The Idle Mode stops the CPU while allowing the

RAM, timer/counters, serial port and interrupt system to continue functioning. The Power-down

Mode saves the RAM contents but freezes the oscillator disabling all other chip functions until

the next hardware resets.


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Pin Diagram

Figure 3.5.1.1 pin diagram of microcontroller AT89C51

The above figure 3.5.1.1 shows the pin diagram of microcontroller AT89C51. Where it

has 40 pins ,in which it has three ports namely port1 (P1.0-P1.7), port(P2.0-2.7), port(P3.0-3.7).

Port 1

Port 1 is an 8-bit bi-directional I/O port with internal pullups. The Port 1 output bufferscan sink/source four TTL inputs. When 1s are written to Port 1 pins they are pulled high by the

internal pullups and can be used as inputs. As inputs, Port 1 pins that are externally being pulled

low will source current (IIL) because of the internal pullups. Port 1 also receives the low-order

address bytes during Flash programming and verification.


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Port 2

Port 2 is an 8-bit bi-directional I/O port with internal pullups. The Port 2 output buffers

can sink/source four TTL inputs. When 1s are written to Port 2 pins they are pulled high by the

internal pullups and can be sed as inputs. As inputs, Port 2 pins that are externally being pulled

low will source current (IIL) because of the internal pullups. Port 2 emits the high-order address

byte during fetches from external program memory and during accesses to external data memory

that use 16-bit addresses (MOVX @ DPTR). In this application, it uses strong internal pullups

when emitting 1s. During accesses to external data memory that use 8-bit addresses (MOVX @

RI), Port 2 emits the contents of the P2 Special Function Register.

Port 2 also receives the high-order address bits and some control signals during Flash

programming and verification.

Port 3

Port 3 is an 8-bit bi-directional I/O port with internal pullups. The Port 3 output buffers

can sink/source four TTL inputs. When 1s are written to Port 3 pins they are pulled high by the

internal pullups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled

low will source current (IIL) because of the pullups.

Pin Description

Table 3.1 pin description of AT89C51Pin Number Description

1-8 P1.0 - P1.7 - Port 19 RST - Reset

10-17 P3.0 - P3.7 - Port 318 XTAL2 - Crys tal19 XTAL1 - Crystal20 GND - Ground

21-28 P2.0 - P2.7 - Port 2

29 PSEN - Program Store Enable30 ALE - Address Latch Enable31 EA - External Access Enable

32-39 P0.7 - P0.1 - Port 040 Vcc - Positive Power Supply

Thus the pin description of microcontroller AT89C51 is show in the above tabular

column 3.1.


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3.5.2 HEX SCHMITT-TRIGGER INVERTERS (74LS14)

Features

Operation From Very Slow Edges Improved Line-Receiving Characteristics High Noise Immunity

Description

Each circuit functions as an inverter, but because of the Schmitt action, it has different

input threshold levels for positive-going (VT+) and negative-going (VT) signals. These circuits

are temperature compensated and can be triggered from the slowest of input ramps and still give

clean, jitter-free output signals.

Pin diagram

Figure 3.5.2.1 pin diagram of IC 7414

The pin diagram of inverter IC 7414 used is shown in the above figure 3.5.2.1.

These circuits are temperature compensated and can be triggered from the slowest of input ramps

and still give clean, jitter-free output signals.


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3.5.3 HALF-BRIDGE DRIVER (IR2111)

Features

Floating channel designed for bootstrap operation

Fully operational to +600V

Tolerant to negative transient voltage

dV/dt immune

Gate drive supply range from 10 to 20V

Under voltage lockout for both channels

CMOS Schmitt-triggered inputs with pull-down

Matched propagation delay for both channels

Internally set dead time

High side output in phase with input

Description

The IR2111(S) is a high voltage, high speed power MOSFET and IGBT driver with

dependent high and low side referenced output channels designed for half bridge applications.

Proprietary HVIC and latch immune CMOS technologies enable ruggedized monolithic

construction. Logic input is compatible with standard CMOS outputs. The output drivers feature

a high pulse current buffer stage designed for minimum driver cross-conduction. Internal dead

time is provided to avoid shoot-through in the output half-bridge. The floating channel can be

used to drive an N-channel power MOSFET or IGBT in the high side configuration which

operates up to 600 volts


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CHAPTER 4

CPTS SECONDARY SECTION

4.1 BLOCKS OF PRIMARY SECTION

The primary section has three main blocks

1. Secondary Inductor

2. Rectifier

3. Boost Converter

4. Voltage Regulator

5. Train Motor

6. Battery

4.1.1 CIRCUIT DIAGRAM OF CPTS SECONDARY SIDE

The circuit diagram of the Power Transfer primary section is shown in the figure 4.1

below


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4.2 Very Fast Soft Recovery Avalanche Rectifier (BYV26)

Features

Glass passivated junction

Hermetically sealed package

Very low switching losses

Low reverse current

High reverse voltage

Applications

Switched mode power supplies

Highfrequency inverter circuits


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DescriptionsDiode, ultrafast, 1a, 1000v; diode type:soft recovery; voltage, vrrm:1000v; current, if

av:1a; current, ifsm:30a; time, trr typ:75ns; voltage, vf max:2.5v; temperature, tj max:175c;

termination type:axial leaded; operating temperature range:-55c to +175c; case style:sod-57;

no. of pins:2; current, ifs max:30a; external diameter:3.8mm; external length / height:4.6mm;

forward voltage:2.5v; time, trr max:75ns

Figure 4.2.1 rectifier (BYV26)

Terminals: Plated axial leads, solderable per MIL-STD-750, Method 2026

Polarity: Color band denotes cathode end

Weight: approx. 369 mg

4.3 3-Terminal 1A Positive Voltage Regulator (7809)

Features Output Current up to 1A

Output Voltages of 5, 6, 8, 9, 10, 12, 15, 18, 24V

Thermal Overload Protection

Short Circuit Protection

Output Transistor Safe Operating Area Protection

Description

The KA78XX/KA78XXA series of three-terminal positive regulator are available in the

TO-220/D-PAK package and with several fixed output voltages, making them useful in a wide


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range of applications. Each type employs internal current limiting, thermal shut down and safe

operating area protection, making it essentially indestructible. If adequate heat sinking is

provided, they can deliver over 1A output current. Although designed primarily as fixed voltage

regulators, these devices can be used with external components to obtain adjustable voltages and

currents. And the pin diagram is shown in figure 4.3.1

Figure 4.3.1 Pin Diagram of 7809

4.4 SILICON POWER DARLINGTON TRANSISTOR (TIP122)

DESCRIPTION

The TIP120, TIP121 and TIP122 are silicon Epitaxial-Base NPN power transistors in

monolithic Darlington configuration mounted in Jedec TO-220 plastic package. They are

intented for use in power linear and switching applications. The complementary PNP types are

TIP125, TIP126 and TIP127, respectively.


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CHAPTER 5COMPARISON ,ADVANTAGES AND

DISADVANTAGES

5.1 COMPARISIONS BASED ON CRITERIA

Table 5.1 Comparison of Power Supply TechnologiesCriteria Current

Rail/BrushesCable Contactless,Inductive

Voltage Current DC,AC low frequency DC,AC low Frequency DC,AC high Frequency

No f Phases 1,3 1,3 1

Power Conversion No no yes


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Power Range Up to MW Up to MW Up to MW

Efficiency Low-high high high

Wear and Tear Yes (rail,brushes) Yes,cable no

Maintenance Yes yes no

Reliability Medium medium high

Sensitivity Environment Dust,ice No no

Safety Aspects Not isolated /hazards Isolated isolated

EMV,EMI Effects Low Low Medium

Pollution Yes,brushes No no

Cost (Install /Maint.) Medium Medium High/low

Regarding the characteristics shown in Tab.5.1 there are some advantages and

disadvantages of contactless power transfer who are pointed as follows.

5.2 ADVANTAGES

No wear and Tear

High Reliability

No sensitivity against enviornment conditions

Fully isolated system

No maintence requirment

5.3 DISADVANTAGES

Complexe technology


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High power conversion

High investment costs

HISTORY AND CURRENT STATUS

1988 : A power electronics group led by Prof. John Boys at The University of

Auckland in New Zealand, develops an inverter using novel engineering materials

and power electronics and conclude that power transmission by means of

electrodynamic induction should be achievable. A first prototype for a contact-less

power supply is built. Auckland Uniservices, the commercial company of The

University of Auckland, patents the technology


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with a thin EM shield structure with thickness of typically 0.7mm or less. Patent:

US6,501,364. 2001 : Prof. Ron Hui's team demonstrate that the coreless PCB transformer can

transmit power close to 100W in A low-profile low-power converter with coreless

PCB isolation transformer, IEEE Transactions on Power Electronics, Volume: 16

Issue: 3 , May 2001. A team of Philips Research Center Aachen, led by Dr. Eberhard

Waffenschmidt, use it to power an 100W lighting device in their paper "Size

advantage of coreless transformers in the MHz range" in the European Power

Electronics Conference in Graz. 2002 : Prof. Shu Yuen (Ron) Hui extends the planar wireless charging pad concept

using the vertical flux approach to incorporate free-positioning feature for multiple

loads. This is achieved by using a multilayer planar winding array structure. Patentwere granted as "Planar Inductive Battery Charger", GB2389720 and GB 2389767.

2004 : Electrodynamic induction used by 90 percent of the US$1 billion clean room

industry for materials handling equipment in semiconductor, LCD and plasma screen

manufacture 2005 : Prof. Shu Yuen (Ron) Hui and Dr. W.C. Ho of City University of Hong Kong

publish their work in the IEEE Transactions on a planar wireless charging platform

with free-positioning feature. The planar wireless charging pad is able to charge

several loads simultaneously on a flat surface. 2005 : Prof Boys' team at The University of Auckland, refines 3-phase IPT Highway

and pick-up systems allowing transmission of power to moving vehicles in the lab 2007 : A localized charging technique is reported by Dr. Xun Liu and Prof. Ron Hui

for the wireless charging pad with free-positioning feature. With the aid of the

double-layer EM shields enclosing the transmitter and receiver coils, the localized

charging selects the right transmitter coil so as to minimize flux leakage and human

exposure to radiation. 2008 : Industrial designer Thanh Tran, at Brunel University make a wireless lamp

incorporating a high efficiency 3W LED


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2009 : A simple analytical electrical model of electrodynamic induction power

transmission is proposed and applied to a wireless power transfer system for

implantable devices. 2009 : Sony shows a wireless electrodynamic-induction powered TV set, 60 W over

50 cm.

REFERENCES


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1. Brown., W. C. (September 1984). "The History of Power Transmission by Radio Waves" .Microwave Theory and Techniques, IEEE Transactions on 32 (Volume: 32, Issue: 9 On page(s):1230-1242+ ISSN: 0018-9480): 1230.

2. M.Ryu,et al., Comparison and analysis of the Contactless Power Transfer System Using theParameters of the Contactless Transformer in Proc. 2006. Power Electronics Specialists.

3. A. Ecklebe and A. Lindemann, Analysis and Design of a Contactless Energy TransmissionSystem with Flexible Inductor Positioning for automated Guided Vehicles ,in Proc. 2006 IEEEIndustrial Electronics Conf.

4. URL of Sonys Research http://www.techshout.com/wireless/2009/05/sony-unravels-technology-for-wireless-power-transfer/

5. William Beaty, Yahoo Wireless Energy Transmission Tech Group Message #787 , reprinted inWIRELESS TRANSMISSION THEORY .
http://en.wikipedia.org/wiki/Wireless_energy_transfer#cite_ref-35http://en.wikipedia.org/wiki/Wireless_energy_transfer#cite_ref-35http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1132833http://www.techshout.com/wireless/2009/05/sony-unravels-technology-for-wireless-power-transfer/http://www.techshout.com/wireless/2009/05/sony-unravels-technology-for-wireless-power-transfer/http://en.wikipedia.org/wiki/Wireless_energy_transfer#cite_ref-63http://en.wikipedia.org/wiki/Wireless_energy_transfer#cite_ref-63http://tech.groups.yahoo.com/group/wireless_energy_transmission/http://tech.groups.yahoo.com/group/wireless_energy_transmission/http://www.teslaradio.com/pages/wireless_102.htmhttp://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1132833http://www.techshout.com/wireless/2009/05/sony-unravels-technology-for-wireless-power-transfer/http://www.techshout.com/wireless/2009/05/sony-unravels-technology-for-wireless-power-transfer/http://en.wikipedia.org/wiki/Wireless_energy_transfer#cite_ref-63http://tech.groups.yahoo.com/group/wireless_energy_transmission/http://www.teslaradio.com/pages/wireless_102.htmhttp://en.wikipedia.org/wiki/Wireless_energy_transfer#cite_ref-35

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