26-11-2010, 11:20 PM
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26-11-2010, 11:20 PM
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27-11-2010, 09:25 AM
hi
please go through the following thread for more details https://seminarproject.net/Thread-wirele...harvesting
06-02-2012, 12:20 PM
hi, i want full seminar on "wireless battery charger" n ppt also plz mail to dis id... goush.mdmohiddin9[at]gmail.com
02-03-2012, 10:55 AM
to get information about the topic wireless battery charger full report ppt and related topic refer the link bellow http://project-seminars.com/attachment.php?aid=1912 https://seminarproject.net/Thread-wirele...ull-report https://seminarproject.net/Thread-wirele...1#pid27611 https://seminarproject.net/Thread-wirele...ves--17724
18-09-2012, 04:29 PM
WIRELESS BATTERY CHARGER
WIRELESS BATTERY.pdf (Size: 584.72 KB / Downloads: 53) ABSTRACT This report covers the basis and design of the wireless battery charger. The wireless charger will convert the RF/ microwave signal at 900 MHz frequency into a DC signal, and then store the power into an AAA battery. The project is divided into 3 parts: transmitter, antenna, and charging circuit. A complete discussion of the specifications of the battery charger is provided after data measurements. This report also includes component list, financial, data results, and other key information. INTRODUCTION Portable electronic devices are very popular nowadays. As the usage of these portable electronic devices is increasing, the demands for longer battery life are also increasing. These batteries need to be recharged or replaced periodically. It is a hassle to charge or change the battery after a while, especially when there is no power outlet around. Therefore, our team is inspired to design a wireless battery charger. This wireless battery charger is expected to eliminate all the hassles with today’s battery technology. As for now, there are no known companies that are developing the wireless battery charger. This means that there might be a good opportunity in the market for this type of product. Moreover, people tend to spend more money for convenience that meets the price. The outlook of this device is supported by the above predictions. It would be convenient not having to worry about charging or changing the batteries and still have a working device. The advantage of this device is that it can wirelessly charge up the batteries which can save time and money in a long run for the general public. Base on this concept, the design team has come up with a new way to charge the batteries wirelessly. The project is to make a prototype device that converts microwave signals to DC power. Once the prototype has been proved to be working, it is possible to implement this prototype into other applications such as in television remote control, fire alarm, clock, and places that are far to reach to change battery. DESIGN OVERVIEW This wireless battery charger is designed to operate at 900 MHz. In this project, a power transmitter acts as the power source. It will transmit power to the receiver side. And then, the rectifier circuit in the receiver will convert the RF/ microwave signal into DC signal. After the DC signal is produced, the charging circuit will store the power into the battery. Here is the block diagram of the overall design. PROBLEMS AND SOLUTIONS There are 5 people in the design project team, and it’s a relatively large group compare to others. Each member of the team is responsible to communicate to each other and update the status of the project. In the very early stage of the project, the group had defined some specific roles for each group member, so that each group member had a defined responsibility in the design process. As time went by, the sense of this pre-defined responsibility of individual seemed to get dissolved soon after the EE 198A was over. The progress of the project had been sluggish since the beginning of the semester and caused some uprising frustration from group members. The communication between group members and the project adviser was decaying as well. The directions of the project that were pre-defined from the previous semester had been changed several times in the beginning of EE 198B. Due to those back-and-forth changes, valuable time had been wasted. Before the final decision was set on working with the circuitry with 900 MHz frequency, the design team had other choices of frequency range in mind. The first choice was 2.4 GHz from commercial wireless routers. The accessibility is one of the main advantages of using 2.4 GHz wireless routers. However, it fails to provide sufficient power to fit our design requirement and lack of test equipment to measure the circuitry. The second choice was to switch the design specifications using 20MHz frequency. The advantage is that at such low frequency it is possible to use function generator as the transmitter. One big disadvantage is insufficient time to build the power amplifier for the transmitter. The antenna design was another problem that we encountered when we picked this frequency. At 20 MHz, a directional antenna becomes very large compare to 2.4 GHz antennas. Finally, the team decided on 900 MHz frequency for its accessibility, power, and size of the antenna. Marketing Plan The working prototype uses Yagi antennas for the design. The prototype may not seem like an attractive design for today’s wireless devices; however it could be implemented into other applications. For instance, it could be implemented onto devices in the tower and only charge up when needed. The team strives to improve the wireless charger using the spiral patch antennas in the future. The spiral antenna is able to pick up a wider range of frequencies instead of just tuned to one particular frequency. In addition, the spiral antennas become smaller at higher frequency which is small enough to fit in a cell phone or any wireless devices. The multiple rectifier design will also increase the received power. Therefore, these improvements show that this project still holds valid market demands. CONCLUSION In conclusion, power loss and efficiency are the major problems for this design project. Our design team has noticed the potential problem whether the converted DC power will be significant enough to charge up the battery. Therefore, the characteristics of the diodes should be mounted directly onto the antenna for minimum power dissipation. In addition to harmonics, the nonlinear diode creates a DC-bias in the resonant circuit which can be extracted without affecting the RF/ microwave characteristics of the resonant circuit. The time varying voltage and current relationship at the physical point of the diode in the cavity determines the loss in the diode and, consequently, the RF/ microwave to DC efficiency.
28-09-2012, 11:48 AM
WIRELESS BATTERY CHARGER
WIRELESS BATTERY.pdf (Size: 584.72 KB / Downloads: 47) ABSTRACT This report covers the basis and design of the wireless battery charger. The wireless charger will convert the RF/ microwave signal at 900 MHz frequency into a DC signal, and then store the power into an AAA battery. The project is divided into 3 parts: transmitter, antenna, and charging circuit. A complete discussion of the specifications of the battery charger is provided after data measurements. This report also includes component list, financial, data results, and other key information. INTRODUCTION Portable electronic devices are very popular nowadays. As the usage of these portable electronic devices is increasing, the demands for longer battery life are also increasing. These batteries need to be recharged or replaced periodically. It is a hassle to charge or change the battery after a while, especially when there is no power outlet around. Therefore, our team is inspired to design a wireless battery charger. This wireless battery charger is expected to eliminate all the hassles with today’s battery technology. As for now, there are no known companies that are developing the wireless battery charger. This means that there might be a good opportunity in the market for this type of product. Moreover, people tend to spend more money for convenience that meets the price. The outlook of this device is supported by the above predictions. It would be convenient not having to worry about charging or changing the batteries and still have a working device. The advantage of this device is that it can wirelessly charge up the batteries which can save time and money in a long run for the general public. Base on this concept, the design team has come up with a new way to charge the batteries wirelessly. The project is to make a prototype device that converts microwave signals to DC power. Once the prototype has been proved to be working, it is possible to implement this prototype into other applications such as in television remote control, fire alarm, clock, and places that are far to reach to change battery. DESIGN OVERVIEW This wireless battery charger is designed to operate at 900 MHz. In this project, a power transmitter acts as the power source. It will transmit power to the receiver side. And then, the rectifier circuit in the receiver will convert the RF/ microwave signal into DC signal. After the DC signal is produced, the charging circuit will store the power into the battery. Here is the block diagram of the overall design. Antenna The antenna plays a very important role. To charge a battery, a high DC power signal is needed. The wireless battery charger circuit must keep the power loss to the minimal. Therefore, there are many considerations to choose the correct parts for the design. The considerations of choosing the appropriate antenna are: 1. Impedance of the antenna 2. Gain of the antenna Taking the above design spec in consideration, the team found Yagi antennas that fit our spec. Below is a picture of the Yagi antenna The impedance of the antenna should match with the output impedance of the power transmitter and input impedance of the rectifier circuit. Non-matching impedance between circuits can cause a tremendous power loss due to signal distortion. Since the output impedance of the transmitter is 50 Ω, the antenna should also have 50 Ω impedance. The higher of the antenna gain yields a better result of the design. However, higher gain will also increase the cost and the size of the antenna. This becomes a major factor in choosing the antenna due to the group’s limited financial resources. After consideration, a 9 dBi Yagi antenna is chosen for the design (see Appendix for specifications) Receiver The receiver’s main purpose is to charge an AAA battery. A simple battery charging theory is to run current through the battery, and apply a voltage difference between the terminals of the battery to reverse the chemical process. By doing so, it recharges the battery. There are other efficient and faster ways to charge the battery, but it requires a large amount of energy which the wireless battery charger can not obtain, yet. Therefore, in our design, we use a straight forward method to charge the battery. Microwave signal is an AC signal with a frequency range of 1 GHz – 1000 GHz. 900 MHz is in between the RF/ Microwave range. No matter how high the frequency is, AC signal is still AC signal. Therefore, the signal can also be treated as a low frequency AC signal. In order to get a DC signal out of the AC signal, a rectifier circuit is needed. PROBLEMS AND SOLUTIONS There are 5 people in the design project team, and it’s a relatively large group compare to others. Each member of the team is responsible to communicate to each other and update the status of the project. In the very early stage of the project, the group had defined some specific roles for each group member, so that each group member had a defined responsibility in the design process. As time went by, the sense of this pre-defined responsibility of individual seemed to get dissolved soon after the EE 198A was over. The progress of the project had been sluggish since the beginning of the semester and caused some uprising frustration from group members. The communication between group members and the project adviser was decaying as well. The directions of the project that were pre-defined from the previous semester had been changed several times in the beginning of EE 198B. Due to those back-and-forth changes, valuable time had been wasted. CONCLUSION In conclusion, power loss and efficiency are the major problems for this design project. Our design team has noticed the potential problem whether the converted DC power will be significant enough to charge up the battery. Therefore, the characteristics of the diodes should be mounted directly onto the antenna for minimum power dissipation. In addition to harmonics, the nonlinear diode creates a DC-bias in the resonant circuit which can be extracted without affecting the RF/ microwave characteristics of the resonant circuit. The time varying voltage and current relationship at the physical point of the diode in the cavity determines the loss in the diode and, consequently, the RF/ microwave to DC efficiency.
15-11-2012, 03:28 PM
WIRELESS BATTERY CHARGER
1WIRELESS BATTERY.pdf (Size: 584.72 KB / Downloads: 63) ABSTRACT This report covers the basis and design of the wireless battery charger. The wireless charger will convert the RF/ microwave signal at 900 MHz frequency into a DC signal, and then store the power into an AAA battery. The project is divided into 3 parts: transmitter, antenna, and charging circuit. A complete discussion of the specifications of the battery charger is provided after data measurements. This report also includes component list, financial, data results, and other key information. INTRODUCTION Portable electronic devices are very popular nowadays. As the usage of these portable electronic devices is increasing, the demands for longer battery life are also increasing. These batteries need to be recharged or replaced periodically. It is a hassle to charge or change the battery after a while, especially when there is no power outlet around. Therefore, our team is inspired to design a wireless battery charger. This wireless battery charger is expected to eliminate all the hassles with today’s battery technology. As for now, there are no known companies that are developing the wireless battery charger. This means that there might be a good opportunity in the market for this type of product. Moreover, people tend to spend more money for convenience that meets the price. The outlook of this device is supported by the above predictions. It would be convenient not having to worry about charging or changing the batteries and still have a working device. The advantage of this device is that it can wirelessly charge up the batteries which can save time and money in a long run for the general public. Base on this concept, the design team has come up with a new way to charge the batteries wirelessly. The project is to make a prototype device that converts microwave signals to DC power. Once the prototype has been proved to be working, it is possible to implement this prototype into other applications such as in television remote control, fire alarm, clock, and places that are far to reach to change battery. DESIGN OVERVIEW This wireless battery charger is designed to operate at 900 MHz. In this project, a power transmitter acts as the power source. It will transmit power to the receiver side. And then, the rectifier circuit in the receiver will convert the RF/ microwave signal into DC signal. After the DC signal is produced, the charging circuit will store the power into the battery. Here is the block diagram of the overall design. Antenna The antenna plays a very important role. To charge a battery, a high DC power signal is needed. The wireless battery charger circuit must keep the power loss to the minimal. Therefore, there are many considerations to choose the correct parts for the design. The considerations of choosing the appropriate antenna are: 1. Impedance of the antenna 2. Gain of the antenna Taking the above design spec in consideration, the team found Yagi antennas that fit our spec. Below is a picture of the Yagi antenna. Receiver The receiver’s main purpose is to charge an AAA battery. A simple battery charging theory is to run current through the battery, and apply a voltage difference between the terminals of the battery to reverse the chemical process. By doing so, it recharges the battery. There are other efficient and faster ways to charge the battery, but it requires a large amount of energy which the wireless battery charger can not obtain, yet. Therefore, in our design, we use a straight forward method to charge the battery. Microwave signal is an AC signal with a frequency range of 1 GHz – 1000 GHz. 900 MHz is in between the RF/ Microwave range. No matter how high the frequency is, AC signal is still AC signal. Therefore, the signal can also be treated as a low frequency AC signal. In order to get a DC signal out of the AC signal, a rectifier circuit is needed. PROBLEMS AND SOLUTIONS There are 5 people in the design project team, and it’s a relatively large group compare to others. Each member of the team is responsible to communicate to each other and update the status of the project. In the very early stage of the project, the group had defined some specific roles for each group member, so that each group member had a defined responsibility in the design process. As time went by, the sense of this pre-defined responsibility of individual seemed to get dissolved soon after the EE 198A was over. The progress of the project had been sluggish since the beginning of the semester and caused some uprising frustration from group members. The communication between group members and the project adviser was decaying as well. The directions of the project that were pre-defined from the previous semester had been changed several times in the beginning of EE 198B. Due to those back-and-forth changes, valuable time had been wasted. Before the final decision was set on working with the circuitry with 900 MHz frequency, the design team had other choices of frequency range in mind. The first choice was 2.4 GHz from commercial wireless routers. The accessibility is one of the main advantages of using 2.4 GHz wireless routers. However, it fails to provide sufficient power to fit our design requirement and lack of test equipment to measure the circuitry. The second choice was to switch the design specifications using 20MHz frequency. The advantage is that at such low frequency it is possible to use function generator as the transmitter. One big disadvantage is insufficient time to build the power amplifier for the transmitter. The antenna design was another problem that we encountered when we picked this frequency. At 20 MHz, a directional antenna becomes very large compare to 2.4 GHz antennas. Finally, the team decided on 900 MHz frequency for its accessibility, power, and size of the antenna. Marketing Plan The working prototype uses Yagi antennas for the design. The prototype may not seem like an attractive design for today’s wireless devices; however it could be implemented into other applications. For instance, it could be implemented onto devices in the tower and only charge up when needed. The team strives to improve the wireless charger using the spiral patch antennas in the future. The spiral antenna is able to pick up a wider range of frequencies instead of just tuned to one particular frequency. In addition, the spiral antennas become smaller at higher frequency which is small enough to fit in a cell phone or any wireless devices. The multiple rectifier design will also increase the received power. Therefore, these improvements show that this project still holds valid market demands. CONCLUSION In conclusion, power loss and efficiency are the major problems for this design project. Our design team has noticed the potential problem whether the converted DC power will be significant enough to charge up the battery. Therefore, the characteristics of the diodes should be mounted directly onto the antenna for minimum power dissipation. In addition to harmonics, the nonlinear diode creates a DC-bias in the resonant circuit which can be extracted without affecting the RF/ microwave characteristics of the resonant circuit. The time varying voltage and current relationship at the physical point of the diode in the cavity determines the loss in the diode and, consequently, the RF/ microwave to DC efficiency. 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. |
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