User:Medelen8/ENES100/Wireless Electricity Design

Problem Statement
Use principles of electricity, magnetism, and induction to wirelessly power a load over a span greater than one meter

Requirements for each element or component derived from system level goals and requirements

 * light up an Led wirelessly
 * convert energy from a distance of 1-2 feet
 * balance distance and efficiency of bulb
 * convert AC/DC power
 * measuring magnetic field between the transmitting and receiving coil
 * distinguish between power and distance

Purpose In this project we will create a method that can transmit power without wires. Connecting a power source, which will be an AC source to an inductive coupling system that will produce a magnetic field in order to transmit energy through out the air, will complete this. This will require a coil to send off energy to a receiving coil and will happen by transferring the energy through the first coil and producing the magnetic field to the other coil. That coil will then make a signal expending this magnetic field. the diagram of this whole design process will start form the power source connected to the transmitting coil and which will have 1 foot of space between the receiving coil that is connected to an AC/DC output.
 * The purpose of this project is to produce wireless energy transfer system that allows future methods to wirelessly turn on power. The goal is to have a high amount of efficiency at a distance of one 1 ft.

Alternatives in design
Below in Figure A is a digram i created of our conversion for its wireless power efficiency. This shows the conversion from coil to coil. Using an AC power will create enough energy to work, also the rectifier will be connected to the power in order to convert currency through a flow going in one direction. While the current sensor finds currency between an AC to DC converter so this will create a signal to the other coil and it will give it voltage.

The design of this whole method is to take energy from an AC power and let it transfer wirelessly. This will contain a DC converted to an AC power to light up the bulb. Resonant inductive coupling Is how this power will be converted this all depends on this communication the transmitting and receiving coils have together. The only way for us to do this is to be able to make the transmitting coil larger than the other coil, but not too much bigger.
 * In figure B it shows the inductive coupling this creates a frequency for the magnetic field; which is very important in this system this shows from coil to coil. Where the transmitting coil is connected to the power and wiring and the receiving coil is attached to the light bulb.
 * The efficiency of this project will depend on the coils distance and the size of it and the power of our source will be connected to the transmitting coil and will then wirelessly transfer to the receiving coil and that energy will then go towards the bulb to light up.
 * The system:
 * Efficiency:
 * For us to test how efficient this is we must test different types of coils we will use and that is what me and my group did this week. Below I posted different methods of the usage of coils when checking.  The problem is finding good efficiency but at the same time trying to find a far enough distance.

The initial design
process
 * through testing we had to test the currency by using a volt meter we had to test the current on the coils and that was are problems since it wasn't receiving the amount of currency we needed so we had to correctly fix the coils. Also we used a breadboard to add all the wiring we needed many capacitor and resistors like 470pf, 1nf, and BD137 attached to the breadboard.
 * While we hook up the light bulb to the coil it will change the resonant very little with its frequency of the coil that is being received, we will then need a signal coming from both coils and the voltage would be powered by an AC power which will at least get the bulb to light up dimly. For us to be able to increase the brightness we will have test this by increasing the voltage from the AC power we will be using.

(Found on this site: http://skory.gylcomp.hu/kapcs/kapcs.html )

This process was not successful when lighting up the LED

Experimental prototypes and testing conducted during design
We didn't had any prototypes, but did do alot of testing during this project.

First Circuit


 * These are some pictures of us testing our another design. We found this design on the internet. we connected everything as the website told to do. but it wasn't a great success. The coil wasn't receiving the current, there was a problem with the transisitor, it wasn't passing the current to the coil. so we decided to find different design.


 * This is a video we made while testing the LED. In this video we connected a AC Power converter to the computer and gave the power to LED, the computer software showed us that how much current it was receiving. The coils that was connected to LED was receiving 30MV current, Which was too little to imagine and wasn't enough for LED to light up.

Second Circuit


 * with an unsuccessful attempt in our first circuit, we had to find another circuit that could help us. These are some pictures of us testing the new circuit we found with different coils. The negative end connects to the 3 100um inductors, which is connected to the emitter pin of the transistor. the positive end connects to the 33k resistor and the capacitor. the capacitor is connected to the base pin of the transistor. Finally, the 2 ends of the coil is connected to the collector pin of the transistor and the ends of the resistor+capacitor.


 * In our first attempt, the coils were about 2.5 inches in diameter and had just 1 turn. There was current flowing through the first coil, however, we could not get the secondary coil to receive that power. After researching, we learned that the coil needs to be wounded atleast twice for voltage to be created(Faraday induction).


 * Using the same circuit, we made new coils out of coated copper wires. They were 2.5 inches in diameter and 5 wounds. The same problem as the first setup still existed, first coil had current going through but the secondary coil was not receiving any voltage.


 * This was our third testing. We obtained a Large coil that had about 3200 wounds. We thought this would be good because the more rotation we had, the more voltage it can potentially produce. This time, in order to visibly check if the first coil was receiving power and was sending out magnetic field, we measured the magnetic field with a Labquest handheld machine paired with a magnetic field sensor. As you can see in the picture below, it was creating about 0.3931mT, which is about the same magnetic field created by an actual magnet. However, the secondary coil still did not receive voltage.

Appropriate optimization in the presence of constraints
Not Applicable

Iteration until convergence
Not Applicable

The final design


With all the required background research done it developed to be a clear understanding of what a simple design factors the whole system would need. First we wanted a process to design an oscillator, which would require the transfer signal that would conduct the power. Oscillators do not usually send out power, therefore it was required that our group should make a power amplifier to give out a signal back and forth. (We did not get to this step yet) The power amplifier would then send off the output power to the transmitting coil. Resulting, a receiving coil would be built about 1 foot away to transfer the transmitting power. But, the receiving coil would have an interchanging current, since that caused a problem towards powering a DC source we would use a rectifier that would help give voltage towards the AC power to help the voltage for the DC source. To finalize the circuit design we must add an electric load.

''Wirelessly powering a light bulb we intended on using a transmitting and receiving power of a 40 cm in diameter coils in loops for the coils to transfer energy and having a frequent resonance of about 8 MHz. The distance required to power the bulb is about about one to two feet. These result all in the way the coils are being tested'''


 * The matrerials used in the final design

Inductors: Changes magnetic field and induce current(voltage). If the magnetic field is present, but not changing, it will NOT produce any current. Inductance is measured in Henrys. Henry = voltage/Amp. If current increases, the inductor resists the increase and that is how it makes wave-like properties in magnetic field that produce voltage. The coils need to be intersecting several times in order to create voltage. The inductor is probably the most crucial part of this circuit because it is the part that is responsible for producing voltage within the current.

Capacitors: Stores electricity. Capacitance is measured in Farad. Capacitance = Q(magnitude of charge on one of the conductors)/V. We need capacitors in the circuit because without the electricity being stored in small quantities, the inductors cannot do it's job of causing the magnetic field to change.

Transistors: Amplifies or switches electrical signal on/off.

Technical and scientific knowledge
Wireless Electricity technology will depend on the magnitude of the magnetic field. Magnetic fields connect to each other not very strongly with biological bodies and are scientifically considered to be safe. Devices that use wireless electricity are being considered to fulfill the safety standards. Therefore wireless electricity that can transfer power varies on the receiving coil. If there is a distance that can receive a high enough efficiency it will work by using a high power source that can make it as efficient as possible. Witricity is constructed on mainly strong resonant coupling, which is how this power will be converted, and this all depends on the communication the transmitting and receiving coils have together.

Electromagnetism is used throughout this project when it creates an electric field that goes back and forth through producing a magnetic field. We also found that the use of magnetic induction happens when using coils in loops that can give out enough currency from a AC power, and that is efficient enough to create an oscillating magnetic field in the area of the loops, where another coil is placed to actually power the light bulb. This uses induction to transfer power from one coil to the receiving coil We also used the power of energy coupling that happens when a source of energy has a connection to the light bulb. We would transform the currency at a different voltage to test its power and contact between the coil that is being received to the light bulb.


 * Formulas

Ampere's Law - If there is a motion of charge (current), there is always a circulation of magnetic fields associated with it. ( B is proportional to l)

Faraday Induction - If there is a change in the magnetic field, there is a voltage created in that magnetic field (V is proportional to dB/dt)

Lenz's Law - the voltage and current always flow in opposite direction. If there are 2 coils, each will flow in opposite direction (V = -dB/dt)

These laws not only help us to understand what we need to build, but it also helps us to know WHY wireless electricity works.

Information obtained from:Here

Equations
 * This is the equation for the coils. This equation helps to make the coils right size and right turns. It also gives a better explaining of coils. It helps to get the right inductance and capacitance of the coil.

Inductance(µH)= (rn)^2 / 22.9 r + 25.4 l

L = inductance (µH)

r = mean radius of coil (cm)

N = number of turns

l = length in cm

N = 6 turns

r = 3.5cm

l = 4cm

L = 2.42μH

C= capacitance

f= 1/2π Squareroot of LC = 13.56MHz

C = 56.9pF

Creativity, problem solving, and group decision-making
Me and my group had a hard time on deciding which mechanism would work when lighting up an LED. We tried many methods with using coils, but each were not successful. we had problems with finding currency, having enough voltage, and the use of power. Below aer the different techniques we tried

In our lest testing for lighting up the LED we used coils wrapped around a bar and used a magnet as a power to distribute energy, but their were problems that the coils were receiving currency but at a very low rate we measured this by using using millivolts. You can see below in the pictures that shows the voltage and currency.


 * we also tested different coils, and in the picture below was a coil that was too dangerous to use for this project Coiling Project Wireless Electricity Design.png
 * while these coils had some problems to because this copper coil wasn't allowed to touch in the loops or else it won't send any energy

Prior work in the field, standardization and reuse of designs (including reverse engineering and redesign)
Not Applicable

Performance, life cycle cost and value
Talking about the performance of this project, it will be very useful for the current and the future generation. Nobody likes wires around their office desks, at homes and anywhere. Wires laying around can be dangerous for kids and also to much of headache. With thee wireless electricity, the problem of wires will be finished completely. Nobody ever has to worry about wires anymore. We don't even have to connect our phone to any wire to charge it, it will be charged while in the pocket whenever you come home. There many other useful uses of wireless electricity.

With the final design setup, it is expected to last several years because there are not many parts involved. The main and most important material would be the LED bulbs. All other materials such as transistors, capacitors, resistors and inductors only cost at max $5.00 each. If the user wanted it to be a portable wireless power, they would need to buy batteries, but if it is being used inside homes, there is no need for batteries. We haven't considered anything about the life cycle cost and value yet.

Aesthetics and human factors
This design does not affect the aesthetics of the environment. All it requires is a transmitter coil; while it would draw attention, it would replace the large, obstructive towers constructed to suspend power lines. Human factors are also irrelevant, as there are few plausible outcomes where the human it put in harms way, apart from physically touching the power coil.

Implementation, verification, test and environmental sustainability
The design is fairly easy to implement in a real world environment. A transmitter coil it required to create the magnetic field, while a receiver coil can be attached to the load to induct an electric current. Once placed, the device would require very little maintenance, unless in extreme cases, such as circuit overloads or sudden electromagnetic pulses from the outside. Testing it would be just as easy, using the same concept of transmitting and receiving coils. The device has very little to do with the environment, other than the slight effect magnetic fields have on plant growth.

Maintainability, reliability, and safety

 * 1) 	 Makes the procedure more convenient and therefore more necessary to customers, by removing the need for a wire connected to an outlet or substituting a battery.
 * 2) 	Make things more reliable by removing the most failure disposed to section in most electronic system like the cord.
 * 3) 	Wireless electricity helps environmentally by reducing the need for batteries that wont be used. Since using an interconnected network that will produce electricity power is a lot cheaper and more environmentally.
 * 4) 	Using wireless electricity is much safer because it removes the sparking hazard connected with having less wiring.

WiTricity’s technology exchanges energy through a distance that uses magnetic fields that can go back and forth to allow the wireless energy interchange. With an accurate design the magnetic fields can be fixed to reach human safety standards that restricts anything that will control any relationship of electric currents and magnetic fields of the device. Witricty can efficiently hold energy and is capable to transfer power through a certain distance, even if the scale isn’t high enough for the magnetic field.

The circuit may need to be in closed in a plastic casing (not metal because it will interfere with the wireless signal) because the user may touch the coils which would give them electric shock to some extent.

Robustness, evolution, product improvement and retirement
The purpose of this project is to develop technology that can effectively induce a current onto a load circuit or storage device over a certain distance

To improve upon this design we can find different ways on increasing the distance of lighting a bulb more than a couple feet away. To do so we would need a larger magnetic filed between both coils. Creating a larger range can happen by adding a third existing coil. and achieve high efficiency at the same time.
 * we can also use a method of auto tuning. The system only achieves high efficiency at a single point between the transmitter and receiver. the system adapts when auto tuning is enabled and when the light bulb is out of the range it turns off but when it is brought back to the range it can rapidly find the maximum power point and get a high efficiency.

Wireless Power should benefit society by reducing the amount of necessary materials to transport electricity over long distances. With the technology of today, we rely on metallic (usually copper) wires that allow electricity to flow through them. However, with the concept demonstrated in this project, we could eliminate the need for power lines and instead embrace Tesla's idea for free, wireless electricity