Nikola Tesla the electric man
Nikola Tesla was born in 1856 in Smiljan, Croatia, the Austro-Hungarian Empire. His father was a priest in the Serbian Orthodox church.
His invention help in the production, transmission and application of electric power. It also includes first alternating current motor and developed AC generation and transmission.
Nikola tesla is one of history's most important energy-related inventors and engineers following are some
1.Direct current -which is electricity flowing in a constant direction, possessing a voltage with constant polarity.
Alternating current in which current flowing in one direction in a circuit and then reversing to flow in the other, as a current switching direction back and forth, this electricity is known as Alternating Current (AC). In alternating current , the current flows in one direction in a circuit and then reversing to flow in the other.
To produce ac current a machine is constructed to rotate a magnetic field around a set of stationary wire coils with the turning of a shaft, AC voltage will be produced across the wire coils as that shaft is rotated, according to Faraday’s Law of electromagnetic induction.
Alternating current is simply the movement of electrical charge in medium that changes direction periodically. Where as direct current (DC), the movement of charge is only in one direction and is constant.
AC can be produced using a device called an alternator. This device is a special type of electrical generator designed to produce alternating current.
A loop of wire is rotates inside of a magnetic field, which induces a current along the wire. The rotation of the wire can come from any number of means: a wind turbine, a steam turbine, flowing water. Because the wire rotates in a magnetic field, a different magnetic polarity periodically, the voltage and current alternates.
DC generators work s on general principle of electromagnetic induction, construction of a DC generator, the coil of wire is mounted in the shaft alternator, and electrical connections are made to this spinning coil , stationary carbon “brushes” contacting copper strips on the rotating shaft. To switch the coil’s changing output polarity to the external circuit constant polarity.
Transformer is a device to step voltage up or down from the powered coil to the unpowered coil.
The AC voltage induced in the unpowered secondary coil is equal to the AC voltage across the powered primary coil multiplied by the ratio of secondary coil turns to primary coil turns.
The secondary coil is powering a load, the current through the secondary coil is just the opposite: primary coil current multiplied by the ratio of primary to secondary turns.
Remote use the technology that controls is infrared (IR) light. The pulses of infrared light is the signal used between a remote control handset and the device controls it.
Remote controls for electronic appliances use a near infrared diode to emit a beam of light that reaches the device. This infrared light picked up by sensors on the receiving device.
After the receiver demodulates the received signal, it applies the frequency filters to separate that signals by using microcontrollers.
Using Microcontroller circuit
The receiver receives the light pulses from the remote and converts it into electrical pulses. The receiver output is given to the microcontroller, which decode the pulses.
The Microcontroller in turn sends a logic high signal to the input pin of the relay. The output pin of the IC develops a logic low signal and the relay connected to that particular output pin gets switched on and in turn switches on the load.
3.Three phase electric power
Definition of Single phase
The single phase needs two wires for completing the circuit, i.e., the conductor and the neutral. The conductor for carrying the current and the neutral for the return path of the current. The single phase supplies the voltage up to 230 volts used for running the small appliances like a fan, cooler, grinder, heater, etc.
Definition of Three Phase
The three phase system needs four wires, three conductors and one neutral. The conductors are out of phase of 120º apart from each other.
The three phase supply is continuous and never completely drops to zero. The three phase system power drawn either in a star or delta configuration. The star connection is used for long distance transmission as it has neutral.
Star-connection and Delta-connection
Three voltage source connected together to form a three phase circuit and the generator. The generator is having three voltage sources which are acting together in 120 phase difference. The arrangement of three single phase circuit with 120 phase difference. Then it will become a three phase circuit.
The electric current in the rotor produce torque is obtained by electromagnetic induction from the magnetic field
Stator is made by stacking thin-slotted highly permeable steel laminations inside a steel or cast iron frame.
Working Principle Of An Induction Motor
In a DC motor, supply is given to the stator winding and the rotor winding. An induction motor only the stator winding is given to an AC.
Alternating flux is produced around the stator winding due to AC supply. This alternating flux revolves with synchronous speed. The revolving flux is called as "Rotating Magnetic Field.
The relative speed between stator RMF and rotor conductors causes an induced emf in the rotor conductors, according to the Faraday's law of electromagnetic induction. The rotor conductors are short circuited, rotor current is produced due to induced emf.
An induced current in rotor will also produce alternating flux around it. This rotor flux is behind the stator flux. The direction of induced rotor current tend to oppose.
The relative velocity between rotating stator flux and the rotor. The rotor rotates in the same direction as of stator flux to minimize the relative velocity.
But the rotor never achieve the synchronous speed. This is the basic working principle of induction motor, single phase of 3 phase.
The AC power supplied to stator creates a magnetic field that rotates in synchronism with the AC oscillations.
A synchronous motor's rotor turns at the same rate as the stator field, an induction motor's rotor rotates slower speed than the stator field.
6.A Tesla coil
It consists of two parts: a primary coil and secondary coil, each with its own capacitor. The two coils and capacitors are connected by a spark gap. A spark gap of air between two electrodes that generates the spark of electricity. An outside source connected to a transformer powers. Tesla coil is two open electric circuits connected to a spark gap.
A Tesla coil needs a high-voltage power source. A regular power source transformer can produce a current.
How it works
The power source is connected to the primary coil. The primary coil's capacitor like a sponge that soaks the charge. The primary coil stand the massive charge , as the coil is made out of copper, a good conductor of electricity.
The capacitor builds huge charge that breaks down the air resistance in the spark gap. By squeezing out soaked sponge, the current flows out of the capacitor the primary coil and creates a magnetic field.
The large amount of energy collapse magnetic field and generates an electric current in the secondary coil. The air between the two coils creates sparks in the spark gap. The energy back and forth between the two coils in the secondary coil and capacitor. The charge in the secondary capacitor gets so high that it breaks free in electric current.
Current from the supply transformer charges the capacitor to a high voltage.
When the voltage in capacitor reaches the breakdown voltage of the spark gap.
A spark starts, reducing the spark gap. It completes the primary circuit and current in capacitor flows through the primary coil
The current flows back and forth between the plates of the capacitor the coil, generate frequency oscillating current in the primary circuit is resonant frequency.
The oscillating magnetic field in the primary winding induces an oscillating current in the secondary winding by Faraday's law of induction. Energy in the primary circuit is transferred to the secondary.
The energy in circuits is limited to the energy stored in the capacitor, oscillating voltage in the secondary increases in amplitude the oscillations in the primary decrease to zero.
The secondary coil are open, it acts as a tuned circuit due to the capacitance between the turns of the coil and the capacitance of the toroid. Current flows back and forth through the secondary coil. Capacitance, the oscillating voltage across the secondary coil on the output terminal is larger than the primary voltage.
The secondary current creates a magnetic field that induces voltage back in the primary coil, the energy is transferred to the primary. This energy shifting rapidly back and forth between the primary and secondary tuned circuits as heat in the spark gap and resistance of the coil.
The current in the spark gap is no longer sufficient to keep the air in the gap ionized, the spark terminating the current in the primary circuit. The oscillating current in the secondary.