Sunday 23 June 2013

Development of Wireless Battery Charging System

Development of Wireless Battery Charging System (IA-B212-13)


Abstract

A design for an energy harvesting device is proposed in this project, which enables scavenging energy from ambient radio frequency (RF) electromagnetic waves with covers the study of basis and designs of the wireless battery charger. Compared to common alternative energy sources like solar and wind, RF harvesting has the least energy density. The wireless charger will convert the RF/ microwave signal into a DC signal, and then store the power into a battery. Thus, this project tends to investigate the most suitable method to rectify the frequency to a valuable DC source needed by the load. This project is divided into several part parts: transmitter, receiver, antenna, charging circuit, matching circuit, boost step-up converter and hardware module. A complete discussion of the specifications of the battery charger is provided after data measurements. This research also includes component list, financial, data results, and other key information. Other than that, as result, the development of wireless battery charging system will successful within able to charge with a specific time frame

Introduction

Electronic devices technology like cellular phone and computer tablets became commercially available in the 1990’s. Since then, it has been like a snowball rolling downhill, ever increasing in the number of users and the speed at which the technology advances. When the devices were first implemented, it was enormous in size by today’s standards. This reason is two-fold, the battery had to be large, and the circuits themselves were large. The circuits of that time used in electronic devices were made from off the shelf integrated circuits (IC), meaning that usually every part of the circuit had its own package. These packages were also very large. These large circuit boards required large amounts of power, which meant bigger batteries. This reliance on power was a major contributor to the reason these devices were so big.
Through the years, technology has allowed the electronic devices to shrink not only the size of the ICs, but also the batteries. New combinations of materials have made possible the ability to produce batteries that not only are smaller and last longer, but also can be recharged easily. However, as technology has advanced and made our devices are smaller and easier to use, but still have one of the original problems, must plug it into the wall in order to recharge the battery. Most people accept this as something that will never change, so they might as well accept it and carry around either extra batteries with them or a charger. Either way, it’s just something extra to weigh a person down. There has been research done in the area of shrinking the charger in order to make it easier to carry. But as small as the charger becomes, it still needs to be plugged in to a wall outlet. How can something are called “wireless” when the object in question is required to be plugged in, even though periodically?
Now, think about this, what if it didn’t have to be that way? Most people don’t realize that there is an abundance of energy all around us at all times and being bombarded with energy waves every second of the day. Radio and television towers, satellites orbiting earth, and even the cellular phone antennas are constantly transmitting energy. What if there was a way that could harvest the energy that is being transmitted and use it as a source of power? If it could be possible to gather the energy and store it, we could potentially use it to power other circuits. In the case of the cellular phone, this power could be used to recharge a battery that is constantly being depleted.
Of course, right now this is all theoretical. There are many complications to be dealt with. The first major obstacle is that it is not a trivial problem to capture energy from the air. Thus, this research will use a concept called energy harvesting. Energy harvesting is the idea of gathering transmitted energy and either using it to power a circuit or storing it for later use. The concept needs an efficient antenna along with a circuit capable of converting alternating-current (AC) voltage to direct-current (DC) voltage.
Another thing to think about is what would happen when you get away from major metropolitan areas. Since the energy that is trying to harness is being added to the atmosphere from devices that are present mostly in cities and are not as abundant in rural areas, there might not be enough energy for this technology to work. However, for the time being, this research will focus on the problem of actually getting a circuit to work.
This thesis is considered to be one of the first steps towards what could become a standard circuit included in every electronics devices, and quite possibly every. A way to charge the battery of an electric circuit without plugging it into the wall would change the way people use wireless systems. However, this technology needs to be proven first.
It was decided to begin the project with a cellular phone’s battery first because of the relative simplicity of the battery system. Also, after prove that the technology will work in the manner suggested, cellular phones would most likely be the first devices to have such circuitry implemented on a wide scale. This advancement coupled with a better overall wireless service can be expected to lead to the mainstream use of cell phones as people’s only phones. This proposal is an empirical study of whether or not this idea is feasible. This first step is to get an external wireless circuit to work with an existing frequency and rectify the valuable direct current (DC) source where the medium of transmitting energy approximately through the air. With what this research proposed, the paper could pave the way for further study of the RF to DC manipulation as long as enhancement is a major intention.


Doubler Circuit


Table 8: The simulation result for, Doubler Circuit
F [MHz]
V(VPRB:Required) [V] - Real - Imag
I(IPRB:Required) [mA] - Real - Imag
RTL1 - voltage doubler
400
40.238755   -20.326693
239.696052   318.749535
0.905894
404.375
39.973391   -20.461672
242.418958   320.044722
0.906638
408.75
39.708358   -20.592942
245.135347   321.298238
0.907378
413.125
39.443706   -20.720546
247.844639   322.510569
0.908115
417.5
39.179487   -20.844529
250.546270   323.682204
0.90885
421.875
38.915747   -20.964936
253.239695   324.813638
0.909581
426.25
38.652534   -21.081813
255.924384   325.905366
0.910309
430.625
38.389892   -21.195205
258.599828   326.957888
0.911033
435
38.127866   -21.305157
261.265531   327.971706
0.911754
439.375
37.866496   -21.411715
263.921016   328.947324
0.912472
443.75
37.605824   -21.514925
266.565820   329.885246
0.913186
448.125
37.345888   -21.614833
269.199498   330.785978
0.913896
452.5
37.086727   -21.711486
271.821620   331.650027
0.914602
456.875
36.828375   -21.804929
274.431773   332.477900
0.915305
461.25
36.570869   -21.895209
277.029556   333.270103
0.916004
465.625
36.314241   -21.982371
279.614585   334.027143
0.916698
470
36.058524   -22.066462
282.186492   334.749524
0.917389

























Villard Circuit

Table 9: The simulation result for, Villard Circuit
F [MHz]
V(VPRB:Required) [V] - Real - Imag
I(IPRB:Required) [A] - Real - Imag
RTL1 - villard circuit
400
59.261300   9.386068
0.000000   0.000000
1
404.375
59.261300   9.386068
0
1
408.75
59.261300   9.386068
0
1
413.125
59.261300   9.386068
0.000000   0.000000
1
417.5
59.261300   9.386068
-0.000000   0.000000
1
421.875
59.261300   9.386068
0
1
426.25
59.261300   9.386068
0.000000   0.000000
1
430.625
59.261300   9.386068
0
1
435
59.261300   9.386068
0
1
439.375
59.261300   9.386068
0
1
443.75
59.261300   9.386068
0
1
448.125
59.261300   9.386068
0
1
452.5
59.261300   9.386068
0.000000   0.000000
1
456.875
59.261300   9.386068
0.000000   0.000000
1
461.25
59.261300   9.386068
0
1
465.625
59.261300   9.386068
0
1
470
59.261300   9.386068
-0.000000   0.000000
1

























Villard and Doubler Circuit

Table 10: The simulation result for, Villard and Doubler circuit
F [MHz]
V(VPRB:Required) [V] - Real - Imag
I(IPRB:Required) [uA] - Real - Imag
RTL1 - villard + doubler
RTL2 - villard + doubler
400
19.089911   -7.140567
26.214357   29.483946
0.940553
1
404.375
19.057725   -7.163821
27.077503   30.423965
0.940634
1
408.75
19.025416   -7.187381
27.962106   31.381531
0.940715
1
413.125
18.992982   -7.211228
28.868538   32.356728
0.940797
1
417.5
18.960422   -7.235346
29.797159   33.349608
0.940881
1
421.875
18.927732   -7.259718
30.748342   34.360243
0.940965
1
426.25
18.894911   -7.284327
31.722435   35.388626
0.941049
1
430.625
18.861957   -7.309158
32.719821   36.434837
0.941135
1
435
18.828870   -7.334197
33.740883   37.498946
0.941221
1
439.375
18.795649   -7.359429
34.785977   38.580944
0.941308
1
443.75
18.762291   -7.384840
35.855495   39.680901
0.941396
1
448.125
18.728796   -7.410417
36.949804   40.798821
0.941484
1
452.5
18.695165   -7.436147
38.069296   41.934757
0.941573
1
456.875
18.661395   -7.462019
39.214351   43.088725
0.941663
1
461.25
18.627488   -7.488019
40.385351   44.260738
0.941753
1
465.625
18.593442   -7.514137
41.582680   45.450803
0.941845
1
470
18.559257   -7.540361
42.806743   46.658972
0.941936
1
  

   

Charge the load with using the frequency


On this condition, our project’s tests are intended to execute with load by using the ambient frequency as a result of analysis using the RF.  From this part, the source from the voltage stabilizer battery will charge the load and directly proportional voltage stabilizer getting charge from the energy harvesting simultaneously.  Thus, the execution of analysis must sure it will charge our hand phone, Samsung Galaxy Note 1.

Project implementation and testing


Result and Discussion
Figure 100: Combine with pure voltage battery (v), current (a/h), frequency (f) and load output (V) vs. time with load (Samsung galaxy note 1) 

Table 18: table of charge the load with using the frequency
TIME
(MINUTE)
PURE VOLTAGE BATTERY (V)
BATTERY VOLTAGE (V)
CURRENT (A/H)
FREQUENCY (F)
OUTPUT WITH LOAD (V)
POWER
(W)
0
1.42
1.44
1.75
0.766
4.438
6.657
10
1.42
1.288
1.75
1.131
4.439
6.6585
20
1.43
1.272
1.75
1.145
4.436
6.654
30
1.44
1.283
1.75
0.997
4.438
6.657
40
1.44
1.284
1.75
0.852
4.438
6.657
50
1.43
1.281
1.75
0.778
4.437
6.6555
60
1.44
1.28
1.75
0.764
4.438
6.657
70
1.42
1.44
1.75
0.766
4.438
6.657
80
1.42
1.288
1.75
1.131
4.439
6.6585
90
1.43
1.272
1.75
1.145
4.436
6.654
100
1.44
1.283
1.75
0.997
4.438
6.657
110
1.44
1.284
1.75
0.852
4.438
6.657
120
1.43
1.281
1.75
0.778
4.437
6.6555
130
1.44
1.28
1.75
0.764
4.438
6.657
140
1.42
1.44
1.75
0.766
4.438
6.657
150
1.42
1.288
1.75
1.131
4.439
6.6585
160
1.43
1.272
1.75
1.145
4.436
6.654
170
1.44
1.283
1.75
0.997
4.438
6.657
180
1.44
1.284
1.75
0.852
4.438
6.657
190
1.43
1.281
1.75
0.778
4.437
6.6555
200
1.44
1.28
1.75
0.764
4.438
6.657
210
1.42
1.288
1.75
1.131
4.439
6.6585
220
1.43
1.272
1.75
1.145
4.436
6.654
230
1.44
1.283
1.75
0.997
4.438
6.657


The Observation of the Result

            From what has been shown on the graph for the real approached and the simulation above, the voltage doubler is better compare than Villard voltage. From the aspect of voltage, voltage doubler more reliable to harvests because the both part of research, the real approached and simulation have a better result. The equilibrium of doubler voltage and doubler ampere is stand the research more convince to imply the success of this research The Voltage doubler can produce a maximum frequency of harvesting and do the same for its ampere. So, this research has revealed that the Watt, p that voltage doubler produce are better than Villard Circuit. The ampere that Villard circuit produce is 0A if guided through the simulation result. This part of research was conveyed us to make a decision that we will use the Doubler Circuit for proposed of the research, frequency harvesting.
            For the second part of the research, the analysis using the voltage stabilizer has opened a new chapter in which, using the voltage stabilizer has played a very important role in this study. The both of analysis of using the frequency and without using the frequency allow us to identify the real concept of the application. In the meantime, we have made a discovery where this study has shown that use the Radio Frequency’s energy harvesting is something that can be implemented to produce a constant DC output with assist the voltage stability and boost converter and yield data for future research.

Conclusion

From the research results, it is found that the proposed voltage doubler circuit and Villard circuit operates at the frequency of 470 MHz with the specified input power levels. The results have shown that there is feasible to harvest the ambient of radio frequency with lie on distance. This is significant, as the work shows that RF energy in the GSM- 470 band can be harvested from the ambient RF source using the Doubler circuit topology. The power density levels from a GSM base station is expected from 0.5 W/m2 to 2 W/m2 for a distance ranging from 100 cm - 650 cm.
Experimental results show that this research have completed the goal of being able to charge the mobile phone approximately in area 80cm2 directly from ambient frequency and approximately able to charge the mobile phone range it over 6.5 meters by using the single battery while the ambient frequency was able to charge the battery indeed. Circumventing the proprietary circuitry in the charging path will allow future adaptation of the wireless RF energy harvesting concept produced by this research.
As the wireless technology is getting popular nowadays, the demand of battery is also increasing. The battery needs to be recharged or changed eventually. Therefore our team is inspired to design the wireless battery charger. This wireless battery charger will eliminate all the hassle with the battery.
As for now, there are no known companies which develop the wireless battery charger. This means that the opportunity is very big. Also, people tend to spend more money for convenience. It gives more reason that this device will have a very good market.