Electro Static has been discovered since several centuries ago, where some types of materials will be mysterious and interesting if rubbed between each other. For example, after rubbing silk with a piece of glass, then the two objects will tend to stick, not only that, when the two are about to be separated, then there is a force that attracts each other.
Electrostatic 1
Glass and silk are not the only objects that have this kind of behavior (static electricity). Any object can react the same way. Have you ever rubbed your body parts with a balloon? If not, please try it between the balloon and your hair, then you will get a new experience about the phenomenon of electrostatics. Other materials such as paraffin wax and wool are also recognized to generate quite strong electrostatics, when both are rubbed together.
Electro Static 2
Another interesting thing is that when two objects with the same basic material are rubbed together, what happens is that they repel each other.
Electro Static 3
In addition, it was also found that each material exhibits the property of attraction or repulsion after being rubbed together, then it can be classified into one of two different categories; attracted to glass and repelled by wax, or repelled by glass and attracted to wax. In addition, it was also found that in addition to reacting to objects that are rubbed against, they also react to other objects.
Electro Static 4
Now, all of this looks even stranger, after we rub them, and before that, they look perfectly normal, this is interesting to study.
Some researchers speculate that invisible "fluids" are being transferred from one object to another after rubbing, and that these "fluids" are capable of affecting long-distance physical forces. Charles Dufay was one of the first researchers to show that there are two types of changes caused by rubbing a pair of certain objects. The fact is that there is more than one type of change caused by the material, the result of which is the force of "attraction" and "repulsion". The hypothesis of "fluid" transfer is known as "charge".
One of the pioneering researchers named Benjamin Franklin, came to the conclusion that there is only one fluid exchanged between the friction of two objects, and the two objects (charges) are not either excess or deficient in fluid. After experimenting with wax and wool, Franklin proposed that the friction between the coarse wool and the fine wax, this causes an excess of fluid in the wool and a deficiency of fluid in the wax. The resulting difference in this context causes the force of attraction, as the fluid tries to regain the balance of charge between the two materials.
Benjamin Franklin
After Franklin's speculation from the process of rubbing wool with wax, the type of charge associated with wax was known as "negative" (due to lack of fluid) while the type of charge associated with wool was known as "positive" (due to excess fluid). Little did he know that his presumption of innocence would cause many future electronics students to become confused.
The first precise measurement of electric charge was made by French physicist Charles Coulomb in 1780 using a device called a torsional balance to measure the force produced between two electrically charged objects. Coulomb's work influenced the development of the unit of electric charge named in his honor. If two "point" objects (hypothetical objects with no appreciable surface area) both charged with a force of 1 coulomb, and placed 1 meter (about 1 yard) apart, they would produce a force of about 9 billion newtons (about 2 billion pounds), either pulling or pushing, depending on the type of charge involved.
Charles Coulomb
The next generation of researchers found that the "fluid" was actually made up of tiny pieces of matter called electrons, hence the name "electron" in honor of the ancient Greek scientist. Experiments have since revealed that all matter is made up of tiny "building-blocks" known as atoms. In turn, research has revealed that the structure of atoms is made up of tiny particles. Atoms have 3 basic particles called protons, neutrons, and electrons. Atoms are too small to be seen with the naked eye, but if we look at them with a special microscope, they will look like this:
Atomic Particles
Even though each atom in a piece of cloth tends to stick together as a unit, there is actually a lot of empty space between the electrons and the cluster of protons and neutrons in the middle.
The simplest model is that of the element carbon, with six protons, six neutrons, and six electrons. Atoms in any matter, always have very tightly coupled particles such as protons and neutrons, this is a very important part. The tightly coupled group of protons and neutrons in the center of the atom is called the "nucleus", and the number of protons in the nucleus of an atom determines the identity of its element: changing the number of protons in the nucleus of an atom, you can change it like that, even if you want, you can remove three protons from the nucleus of a lead atom. You will achieve the dream of Alchemists "produce gold atoms!" Tightly binding protons in the nucleus and responsible for the stable identity of a chemical element, and realize the dreams of alchemists for their failure.
Note: An alchemist is someone who can create something from nothing. An alchemist can turn gravel into gold.
Neutrons have a much greater influence on the chemical character and identity of an atom than protons, although they are difficult to add or remove from the nucleus, being so tightly bound. If neutrons are added or removed, the atom will still retain the same chemical identity, but its mass will change slightly, such properties can be found in nuclear, strange things like radioactivity.
However, electrons have significantly more free space around the atom than protons and neutrons. In fact, electrons can be knocked out of their original positions or leave the atom altogether! Much less energy is required to leave the particle in the nucleus. When this happens, the atom retains its chemical identity, but a significant imbalance occurs. In fact, electrons and protons are very unique, they can be attracted to each other. The attraction of rubbed objects is also affected by distance, which is how far the electrons can move from their original atoms to the objects around them.
Electrons tend to repel each other, and protons tend to repel each other. The only reason protons hold together in the nucleus of an atom is because their force is much stronger, called the nuclear force, and it only works over very short distances. Electrons and protons are said to have opposite electrical charges. That is, each electron has a negative charge, and each proton has a positive charge. In equal numbers in an atom, they will be opposites, so the total charge of the atom is zero. This is why the carbon atom pictured here has six electrons: to balance out the electrical charge of the six protons in the nucleus. If an electron were to leave or an extra electron were to arrive, the net electrical charge of the atom would be balanced, leaving the atom "charged" as if it had a hole, which would then interact with other charged particles and charged atoms nearby. Neutrons are neither attracted to nor repelled by other electrons, protons, or neutrons, and are therefore categorized as particles with no "charge" at all.
The process of electrons arriving or leaving occurs exactly when we rub a material, when friction occurs, electrons from atoms of one material are forced to leave their respective atoms and transfer to atoms of the other material. In other words, electrons consist of a 'fluid' hypothesized by Benjamin Franklin. The operational definition of a coulomb is called a unit of electric charge (the force produced between electric charges) is determined to be equal, either excess or deficiency of about 6,250,000,000,000,000,000 electrons. One electron has a charge of about 0.00000000000000000016 coulombs. So the smallest unit carried by an electron is known as the electric charge, this value is defined as the elementary charge.
The resulting imbalance of "fluid" (electrons) between objects is called "static electricity". It is called "static" because the original electrons tend to stay put after being transferred to another material. In the case of wax and wool, it was determined through further experimentation that the electrons in the wool were actually transferred to atoms in the wax, just as Franklin had suspected!, honoring Franklin's suggestion that the wax's "charge" became "negative" and the wool's charge became "positive". The electrons are said to be "negatively" charged. Thus, an object whose atoms have an excess of electrons is said to be "negatively" charged, while an object whose atoms have a deficiency of electrons is said to be "positively" charged.
Review
- All materials are made up of tiny, building blocks known as atoms.
- All atoms contain particles called electrons, protons and neutrons.
- Electrons have a negative electric charge (-)
- Protons have a positive electric charge (+)
- Neutrons have no electric charge.
- Electrons are much more easily separated from their native atoms than protons and neutrons.
- The number of protons in an atom's nucleus determines its identity as a unique element.
Electrical Machine Maintenance
In the field of electricity, a machine is a device in the form of a motor generator. The difference in terms is made based on the difference in its operational function. A motor is a device that converts electrical energy into mechanical rotational energy. While a generator is a device that converts mechanical energy into electrical energy. So, an electric machine can function as a generator, or as a motor.
There are two types of motors:
- DC motor,
- AC motor.
Likewise with generators. There are two types of generators:
- AC generator,
- DC generator.
1. Basic Construction of Electrical Machines
The main part of an electric machine consists of two parts: the moving part called the Rotor, and the stationary part called the Stator. Each part has a coil of wire. In the Stator, the coil of wire functions as a generator of magnetic fields, while in the Rotor, the coil functions as a generator of electromotive force.
Figure 4.1: Basic Construction of an Electrical Machine
2. Working Principles of Motors and Generators
Principle of Motor Rotation Direction
To determine the direction of motor rotation, the left-hand Flamming method is used. The magnetic poles will produce a magnetic field with a direction from the north pole to the south pole. If this magnetic field cuts a conducting wire that is flowing with direct current with four fingers, then a motion force will arise in the direction of the thumb. This force is called the Lorentz force, which is the same as F.
- F = Direction of conducting force (Newton)
- B = magnetic flux density (weber)
- ? = length of conductor wire (meters)
- I = DC Current (Ampere)
- z = Number of conductors
Figure 4.2: Left hand rule for motorcycles
Motor principle: current flow in a conductor under the influence of a magnetic field will produce movement.
The magnitude of the force on the conductor will increase if the current through the conductor increases.
Example 4-1: a DC motor has a magnetic field density of 0.8T. Under the influence of a magnetic field there are 400 conducting wires with a current of 10 A. If the total length of the conductors is 150 mm, determine the force on the anchor.
Principle of Voltage Generation in Generators
A piece of conductor carrying current and moving at a speed v in the influence of a magnetic field will cause an induced voltage of V. To determine the magnitude of the induced voltage caused by the direction of the conductor's movement, the Flamming right-hand method is used. The magnetic field has a direction from the north pole to the south pole. The current in the conductor is in the same direction as the four fingers, while the direction of movement is in the same direction as the thumb, as shown in Figure 4.3.
- V = induced voltage (volts)
- B = magnetic flux density (weber)
- ? = length of conductor wire (meters)
- z = number of conductors
- v = wire motion speed (m/s).
Figure 4.3: Right hand law for a generator
Generator principle: Magnetic fields and the movement of a piece of conductor carrying current will produce voltage.
Example 4-2. The magnetic density of a generator is known = 0.85 T cut by 500 conductor wires, and moving at a speed of 5 m/s. If the total length of the conductor is 100 mm, what is the magnitude of the induced voltage produced?
See Atomic Movement Using an Electron Microscope
See How Atoms In Certain Materials
Atomic Engineering In Semiconductor Industry
Reference
The ebook FEEE - Fundamentals of Electrical Engineering and Electronics is based on material originally written by TR Kuphaldt and various co-authors.
Netizens
Q1: ASEP SURATMAN Dec 24, 2015, 22:53:00 = Nice blog bro! I like the blog!!!
A1: Hello Mr. Asep Suratman, thank you for your appreciation.