Electric Motors

What is a Motor?

A motor is a a machine. It is powered by electricity or internal combustion that supplies power for a vehicle or other devices with moving parts. 

History of Motors:

"Motos find the most practical use in our every day life in form of modern gadgets, devices, and appliances." From the first discovery t today, we have progressed into developing advanced and useful motors that aid us in our every day lives. 

Before 1834, Joseph Henry and Michael Faraday created an early motor using electromagnetic fields. These motors were created with spinning disks or levers but were not powerful enough to do any kind of task. Because of this, it helped lead the way to create better motors in the future.  

Michael Faraday

• Early 1800s: the basic principles of electromagnetic induction was discovered by Oersted, 

  

  Hans Christian Oersted

  Gauss and Faraday. 
• 1800: the invention of the battery by Alessandro Volta 
• 1820: the invention of a magnetic field from electric current by Hans Christian Oersted and Andre Ampere. This lead to the invention the the basic DC motor. 
• 1821: Michael Faraday set out to prove the theory proposed by Oersted and Ampere. He did this by converting electric energy into motion
• 1822: the invention of the first rotating device driven by electromagnetism was built by Peter Barlow
• 1825: the invention of the electromagnet by William Sturgeon
• 1832: The invention of the commutator by William Ritchie and Hippolyte Pixii.
• 1833: Friedrich Emil Lenz published an article on the law of reciprocity of magneto-electric and electromagnetic phenomena. 
• 1834: Thomas Davenport constructed the first real DC electric motor. It was powerful enough to preform certain tasks. His motors were able to preform tasks like moving a trolley on circular tracks. Later on, it turned out that the trolley was the first important application of electric power. Also in May, Moritz Jacobi created the first real rotating electric motor. It set a world record which was improved by him self 4 years later in 1838.

  

  Jacobi's motor

• 1835: 2 Dutchmen created an electric motor that was able to power a small car. 
• 1837: In 1837, the first patent was granted to Thomas Davenport.
• 1838: Jacobi's second motor created was powerful enough to drive a boat full of people across a river. Also, Friedrich Emil Lenz proved a detailed description of his experiments with the generator used to operate his motor.
• 1839/40: Scientist all over the world  managed to recreate his motor as well as create ones with a higher power.
• 1850: Thomas Davenport's death. 30 after his death, full sized electric trolleys were built.
• 1856: the invention of the Double-T-anchor by Werner Siemens.
• 1872: the invention of the drum armature by Friedrich Hefner-Alteneck.
• 1873: the electric motor achieved commercial success
• 1880: trolleys and their power systems were very expensive to build and transport people.
• 1885-1889: the invention of the 3-phase electric power system. That is the basis of the electrical power transmission and advanced electric motors today. This motor is most commonly used in highly dynamic applications such as robots or electric cars

How Motors Work:

"The core function of an electric motor is to convert electrical current into mechanical force."

DIfferent motors work differently but they all work off of the power of the electromagnetic field. There are main types of motors. AC and DC motors. On electric motors, there are parts that all it to function. For example, a rotor or stator. Motors use electromagnetic fields to generate motion. Electric motors function of the principle of magnetism which is alike poles repel and opposite poles attract. Magnets are the base of many motors.

AC Motors:

AC motors use a secondary and primary magnet. The primary winding is connected directly to a power source like a generator or power grid. The secondary magnet receives energy from the primary without directly touching it. These motors have the advantage of auto-change of polarity due to alternating current. It runs at the frequency of the sine wave. The most common of these motors are induction type. Unlike the DC motor, no current passes through the armature coils. The current gets induced through rotation coils instead of them being supplied directly. A typical motor consists of  parts. The first one is an exterior stationary stator with coils that use AC current to produce a revolving magnetic field. The second one is an interior rotor linked to the output shaft that employs torque using the rotating field.

DC Motors:

DC motors were not created from the motors that were made in the 19th century. Rather from eh development of power generators. DC motors the the oldest form of electric motors. Today, they have a dominant market position in the lower power and low voltage. They are powered through a direct current. DC motors have a fixed magnet on the outside. On the inside is an armature that carries current. "As soon as the current passes through the wired armature, it turns into an electromagnet with opposite polarity as of the girls magnet." This cause the armature to continuously rotate. A armature is usually nothing more but a good conductor with copper wire on it. With every half rotation of these motors, the electromagnet gets stuck at the opposite poles and they attract to each other. To get past it, the current needs to be flipped. To do this, a commuter and brushes are used. The commutator allows for the motor to change the direction of the current. It is attached to the armature. Like the motors we built, the brushes rest against the commutator. "The key is that as soon as the armature passes over the maximum flux of the field magnet, the poles of the electromagnet must flip. Because of the flip, the North Pole of the electromagnet is always in line with the North Pole of the field magnet that keeps the armature under constant repulsion."

Disadvantages of DC Motors:

• The brushes wear. Because the brushes are constantly connecting to the commutator, it begins to wear. When that happens, it will increase in low pressure environment. Also, the sparks from the brushes can be hazardous. This is a rare occasion but the sparks from the brushes may cause an explosion if the environment that motor is in is susceptible to it.

Types of Electric Motors:

• Stepper Motors: 
• it is an electro-mechanical device that converts electrical current into torque output. It rotates a number of degrees with each electric pulse. It is also measured in degrees.
• Brushed DC Motors:
• it has a permanent magnetic field that is produced in the stator.
• Brushless DC Motors:
• it has similar operations as the DC motor. The role of the rotor and stator are inverted in the brushless motor. There are no brushes and the function of the commutator takes place by an electronic circuit. 
• Linear Motor:
• it is an electric motor that consists of an unrolled stator. It produces linear force instead of torque like the other motors.
• Servo Motor:
• it is a very small motor with one main function. It select if it wants vertical or horizontal polarization. It is usually used for motion controls. It also uses a special current to make them rotate electrically.

Bibliography:

http://engineering.mit.edu/ask/what’s-difference-between-motor-and-engine

http://www.ece.uah.edu/courses/material/EE410-Wms2/Electric%20motors.pdf

http://www.edisontechcenter.org/electricmotors.html

https://www.eti.kit.edu/english/1376.php

http://www.solarbotics.net/starting/200111_dcmotor/200111_dcmotor.html

http://www.solarbotics.net/starting/200111_dcmotor/200111_dcmotor3.html

http://www.howmotorswork.com/history.html

http://www.howmotorswork.com/type_of_motor.html
http://www.electrical4u.com/electrical-motor-types-classification-and-history-of-motor/

My Motor

My Electric Motor:

Supplies:

• 2 spools of 24 gage copper wire
• 14 gage multistrand wire or lamp wire
• 1 rod of fiber glass
• 1 6 volt battery
• Hot glue gun
• 2 large nails
• Many small screws
• Small Washers
• Wire cutters
• Big Washers
• Drill
• Tape
• Sand paper
• 1 saw
• Wood
• 2 chopsticks
• Wood glue
• Soldering iron
• 1 sheet of copper
• 2 6 inch brackets
• 3 thin metal brackets
• 1 medicine canister
• Alligator clips
• A spool and thread

Procedure:

1. Gather all of your materials
2. Take your piece of wood and cut it in half with your saw. This is so that you will be able to join them together later. By cutting it, it will give you a better area to work with. 
3. Aline your pieces of wood nest to each other so that it almost forms a complete square. Next, take the smallest drill part and drill into the side of the wood at a diagonal. Gradually get bigger with the drills to where you re able to fit a chopstick in. When this is complete on both sides, you will be able to insert that chopstick into it. This will allow you to join the two pieces of wood together. 
4. Once you are done with the drill, take the wood glue and apply it to the two sides that you will be connecting and put some clue into the holes that you create with your drill.

   

   Base coil and Armature 

   Before the glue dries, insert both chopsticks in. Set aside and let dry.
5. Next, take 1 spool of 24 gage copper wire and the 2 6 inch brackets. These materials will be creating your base coil. Overlap the brackets so that it forms a U shape. Add a little hot glue to it so that it will stay together when you begin to wrap it. Do not add too much so that it is not flat. 
6. Before you start wrapping, leave a couple inches off the end so that you will be able to connect it to the battery. When winding your base coil, it is important to try to not overlap the layers of the wire. You have to keep going back and forth until you use up the whole spool of wire. When you have very little wire left, make sure that you leave a little sticking out at the other end so that it will be able to continue the circuit. Now your base coil is done. 
7. To make sure that you did it correctly, test it with the 6 volt battery. Since the wire is coated with enamel, you have to either use sand paper or a flame to take it off so that the electricity will flow through. Once that is done, attach each end of the wire to the battery. A way to test it is by taking some

   

   Testing magnet

   thing metal (paper clip) and see if it will be drawn towards it. 
8. The next thing to build is your armature. The materials need for this is the rod of fiberglass, the piece of copper, tape, the other spool of 24 gage wire, the 2 large nails, the pill canister, the hot glue gun, and the soldering iron. First take the fiberglass rod and the 2 nails. Place the 2 nails on either side of the fiberglass so that they are equal distance from the center and perpendicular to the rod. Put a little glue on the nail and rod to secure it into place. Next, take the wire. Leave about 10 inches out and start winding from the middle out to one side. This is very important that the wraps are neat and do not over lap. If it over laps, it will make the magnet weaker.  From the middle go out to one end and then back. Do that one more time. Once that is complete cross over to the other side and do the same thing. When you are wrapping on the other side, make sure that you are wrapping in the same direction or it will cancel out. When the is done come down and cut the wire so it is the same length of the other end.
9. Put is aside and move onto the pill canister. The pill canister will become your

   

   Commutator

   commutator Take the drill and drill a small hole through the center of the bottle. Keep making the hole bigger until you are able to slide the canister onto the rod. Once it is on the rod, take the piece of copper and cut it in half. The copper will go around the canister and this where the brushes will make contact. Cut the copper so that it goes around the bottle but the ends to not touch. Make sure that there are gaps in between the pieces of copper and the gaps should line up with the tips of the nails. Secure the copper by putting a thin piece of tape on the outer sides of the piece of copper the is farther away from the coil.
10. Next, burn the ends of the wire to get the enamel off agin. Then take the soldering iron and join the ends of wire to the sheet of copper that does no have tape. After it dries, you can put another piece of tape on to make sure that it doesn't move. Doing this, it completes the circuit. Now the armature is done. 
11. To test the armature, connect the battery to the copper with alligator clips. Use the paper clip again and see if it stays on the coil. If so, you can move on to the brushes.
12. Next, it is on to the brushes. The brushes make the motor rotate. Take the multi strand wire and cut 2 8 inch pieces of wire using the wire cutters. Then use the wire cutters to take of the plastic covering on the wire to expose the metal. 
13. Now, you have to secure everything to the wooden board to finish working on the brushes. 
14. First,

    

    Vertical view

    measure off to one side and secure the base coil to the board with screws. After that is complete, take your armature and secure it with 2 thin metal brackets so that the coin will be directly over the base coil. Once the base coil and armature are connected, you can finish the brushes. 
15. One end of one multi strand wire is going to connect to one of the base coil's wires. The other one is going to connect to the battery. Take the one that will connect to the base coil and twist this wire with the 24 gage wire sticking out. The other end of the multi strand wire will touch your commutator. 
16. In order to make sure the brushes are secure and do not move. Take the last thin metal bracket and cut it in half. Screw them down on either side of the commutator. Next, weave the wire through the outer hole and up to the top so that it is standing vertical barely touching the copper. Do this on either side. You might have to bend the wire in order to get it just right. 
17. Lastly, attach the spool to either end of the armature. Glue or tape a little over 4 meters

    

    Spool to pull the car

    of thread to the spool. This will allow you to pull the car.
18. Now it is time to test it. Attach the alligator clips to the motor by attaching one to the wire sticking out from the base coil and the other one to the end of one of the brushes. When you do this, you should see your brushes spark against the copper. By doing this, it is completing the circuit and it should make the motor spin. 

When testing your motor, it usually does not work on the first time. It takes a lot of adjusting and correction. With my motor, the most common problem that I had the most was my brushes. I had to keep adjusting it until I got it just right. It also helps to have a battery that functions and not one that is out of power. 

How it Works:

In a motor, there are negative and positive terminals. In my motor, wither side of the base coil represents that. When the motor is suing, it is constantly switching terminals. When the negative part of the armature is on the positive side, it repels off of it because it wants to go to the negative side and vise versa. This keeps happening and what causes the motor to spin.