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| 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.
