How Electronic Components Work

Electronic gadgets have become an integral part of our lives. They have made our lives more
comfortable and convenient. From aviation to medical and healthcare industries, electronic gadgets
have a wide range of applications in the modern world. In fact, the electronics revolution and the
computer revolution go hand in hand.

Most gadgets have tiny electronic circuits that can control machines and process information. Simply
put, electronic circuits are the lifelines of various electrical appliances. This guide explains in detail about
common electronic components used in electronic circuits and how they work.

In this article I will provide an overview on electronic circuits. Then I will provide more information on 7
different types of components. For each type I'll discuss the composition, how it works, and the
function & significance of the component.

Capacitor

Resistor

Diode

Transistor

Inductor

Relay

Quartz Crystal

Electronic Circuit Overview

An electronic circuit is a structure that directs and controls electric current to perform various functions
including signal amplification, computation, and data transfer. It comprises several different
components such as resistors, transistors, capacitors, inductors, and diodes. Conductive wires or traces
are used to connect the components to each other. However, a circuit is complete only if it starts and
ends at the same point, forming a loop.
The Elements of an Electronic Circuit

The complexity and the number of components in an electronic circuit may change depending on its
application. However, the simplest circuit consists of three elements, including a conducting path, a
voltage source, and a load.

Element 1: Conducting Path

The electric current flows through the conducting path. Though copper wires are used in simple circuits,
they are rapidly being replaced by conductive traces. Conductive traces are nothing but copper sheets
laminated onto a non-conductive substrate. They are often used in small and complex circuits such as
Printed Circuit Boards (PCB).

Element 2: Voltage Source

The primary function of a circuit is to allow electric current to pass through it safely. So, the first key
element is the voltage source. It is a two-terminal device such as a battery, generators or power systems
that provide a potential difference (voltage) between two points in the circuit so that current can flow
through it.

Element 3: Load

A load is an element in the circuit that consumes power to perform a particular function. A light bulb is
the simplest load. Complex circuits, however, have different loads such as resistors, capacitors,
transistors, and transistors.

Electronic Circuit Facts

Fact 1: Open Circuit

As mentioned before, a circuit must always form a loop to allow the current to flow through it. However,
when it comes to an open circuit, the current can’t flow as one or more components are disconnected
either intentionally (by using a switch) or accidentally (broken parts). In other words, any circuit that
does not form a loop is an open circuit.

Fact 2: Closed Circuit

A closed circuit is one that forms a loop without any interruptions. Thus, it is the exact opposite of an
open circuit. However, a complete circuit that doesn’t perform any function is still a closed circuit. For
example, a circuit connected to a dead battery may not perform any work, but it is still a closed circuit.

Fact 3: Short Circuit

In the case of short-circuit, a low-resistance connection forms between two points in an electric circuit.
As a result, the current tends to flow through this newly formed connection rather than along the
intended path. For example, if there is a direct connection between the battery’s negative and positive
terminal, the current will flow through it rather than passing through the circuit.

However, short circuits usually lead to serious accidents as the current can flow at dangerously high
levels. Hence, a short circuit can damage electronic equipment, cause batteries to explode, and even
start a fire in commercial and residential buildings.

Fact 4: Printed Circuit Boards (PCBs)

Most electronic appliances require complex electronic circuits. That’s why designers have to arrange tiny
electronic components on a circuit board. It comprises a plastic board with connecting copper tracks on
one side and lots of holes to affix the components. When the layout of a circuit board is printed
chemically onto a plastic board, it is called a printed circuit board or PCB.

Figure 1: Printed Circuit Board. [Image Source]

Fact 5: Integrated Circuits (ICs)

Though PCBs can offer a lot of advantages, most modern instruments such as computers and mobiles
require complex circuits, having thousands and even millions of components. That’s where integrated
circuits come in. They are the tiny electronic circuits that can fit inside a small silicon chip. Jack Kilby
invented the first integrated circuit in 1958 at Texas Instruments. The sole purpose of ICs is to increase
the efficiency of the electronic devices, while reducing their size and manufacturing cost. Over the years,
integrated circuits have become increasingly sophisticated as technology continues to evolve. That’s
why personal computers, laptops, mobiles phones, and other consumer electronics are getting cheaper
and better by the day.

Figure 2: Integrated Circuits. [Image Source]

Electronic Components

Thanks to modern technology, electronic circuit building process has been completely automated,
especially for building ICs and PCBs. The number and arrangement of components in a circuit may vary
depending on its complexity. However, it is built using a small number of standard components.

The following components are used to construct electronic circuits.

Component 1: Capacitor

Capacitors are widely used to build different types of electronic circuits. A capacitor is a passive two-
terminal electrical component that can store energy in an electric field electrostatically. In simple terms,
it works as a small rechargeable battery that stores electricity. However, unlike a battery, it can charge
and discharge in the split of a second.

Figure 3: Capacitors [Image Source]

A. Composition

Capacitors come in all shapes and sizes, but they usually have the same primary components. There are
two electrical conductors or plates separated by a dielectric or insulator stacked between them. Plates
are composed of conducting material such as thin films of metal or aluminum foil. A dielectric, on the
other hand, is a non-conducting material such as glass, ceramic, plastic film, air, paper, or mica. You can
insert the two electrical connections protruding from the plates to fix the capacitor in a circuit.

B. How Does It Work?

When you apply a voltage over the two plates or connect them to a source, an electric field develops
across the insulator, causing one plate to accumulate positive charge while negative charge gets
collected on the other. The capacitor continues to hold its charge even if you disconnect it from the
source. The moment you connect it to a load, the stored energy will flow from the capacitor to the load.

Capacitance is the amount of energy stored in a capacitor. The higher the capacitance, the more energy
it can store. You can increase the capacitance by moving the plates closer to each other or increasing
their size. Alternatively, you can also enhance the insulation qualities to increase the capacitance.

C. Function and Significance

Though capacitors look like batteries, they can perform different types of functions in a circuit such as
blocking direct current while allowing alternating current to pass or smooth the output from a power
supply. They are also used in electric power transmission systems to stabilize voltage and power flow.
One of the most significant functions of a capacitor in the AC systems is power factor correction, without
which you can’t provide sufficient amount of starting torque to single phase motors.

Filters Capacitor Applications

If you are using a microcontroller in a circuit to run a specific program, you don’t want its voltage to
drop as that will reset the controller. That’s why designers use a capacitor. It can supply the
microcontroller with the necessary power for a split second to avoid a restart. In other words, it filters
out the noise on the power line and stabilizes the power supply.

Hold-Up Capacitor Applications

Unlike a battery, a capacitor releases its charge rapidly. That’s why it is used to provide power to a
circuit for a short while. Your camera batteries charge the capacitor attached to the flash gun. When you
take a flash photograph, the capacitor releases its charge in a split second to generate a flash of light.

Timer Capacitor Applications

In a resonant or time-dependent circuit, capacitors are used along with a resistor or inductor as a timing
element. The time required to charge and discharge a capacitor determines the operation of the circuit.

Component 2: Resistor

A resistor is a passive two-terminal electrical device that resists the flow of current. It is probably the
simplest element in an electronic circuit. It is also one of the most common components as resistance is
an inherent element of nearly all electronic circuits. They are usually color-coded.

Figure 4: Resistors [Image Source]

A. Composition

A resistor is not a fancy device at all because resistance is a natural property possessed by almost all
conductors. So, a capacitor consists of a copper wire wrapped around an insulating material such as a
ceramic rod. The number of turns and the thinness of copper wire are directly proportional to the
resistance. The higher the number of turns and thinner the wire, the higher the resistance.

You can also find resistors made of a spiral pattern of a carbon film. Hence, the name carbon film
resistors. They are designed for lower-power circuits because carbon film resistors are not as precise as
their wire-wound counterparts. However, they are cheaper than wired resistors. Wire terminals are
attached to the both ends. As resistors are blind to the polarity in a circuit, the current can flow through
in either direction. So, there is no need to worry about attaching them in a forward or a backward
direction.

B. How Does It Work?

A resistor may not look like much. One may think it doesn’t do anything except consume power.
However, it performs a vital function: controlling the voltage and the current in your circuit. In other
words, resistors give you control over the design of your circuit.

When electric current starts flowing through a wire, all the electrons start moving in the same direction.
It’s just like water flowing through a pipe. Less amount of water will flow through a thin pipe because
there is less room for its movement.

Similarly, when the current passes through a thin wire in a resistor, it becomes progressively harder for
the electrons to wiggle through it. In short, the number of electrons flowing through a resistor goes
down as the length and thinness of the wire increases.

C. Function and Significance

Resistors have plenty of applications, but the three most common ones are managing current flow,
dividing voltage, and resistor-capacitor networks.

Limiting the Flow of Current

If you don’t add resistors to a circuit, the current will flow at dangerously high levels. It can overheat
other components and possibly damage them. For example, if you connect an LED directly to a battery,
it would still work. However, after some time the LED will heat up like a fireball. It will eventually burn as
LEDs are less tolerant to heat.

But, if you introduce a resistor in the circuit, it will reduce the flow of current to an optimal level. Thus,
you can keep the LED on longer without overheating it.

Dividing Voltage

Resistors are also used to reduce the voltage to the desired level. Sometimes, a particular part of a
circuit such as a microcontroller may need a lower voltage than the circuit itself. This is where a resistor
comes in.
Let’s say your circuit runs off of a 12V battery. However, the microcontroller needs only a 6V supply. So,
to divide the voltage in half, all you have to do is place two resistors of equal resistance value in series.
The wire in between the two resistors will have halved the voltage of your circuit where the
microcontroller can be attached. Using appropriate resistors, you can lower the voltage within the
circuit to any level.

Resistor-Capacitor Networks

Resistors are also used in combination with capacitors to build ICs that contain resistor-capacitor arrays
in a single chip. They are also known as RC filters or RC networks. They are often used to suppress
electromagnetic Interference (EMI) or Radio Frequency Interference (RFI) in various instruments,
including input/output ports of computers and laptops, Local Area Networks (LANs), and Wide Area
Networks (WANs), among others. They are also used in machine tools, switchgears, motor controllers,
automated equipment, industrial appliances, elevators, and escalators.

Component 3: Diode

A diode is a two-terminal device that allows electric current to flow in only one direction. Thus, it is the
electronic equivalent of a check valve or a one-way street. It is commonly used to convert an Alternating
Current (AC) into a Direct Current (DC). It is made either of a semiconductor material (semiconductor
diode) or vacuum tube (vacuum tube diode). Today, however, most diodes are made from
semiconductor material, particularly silicon.

Figure 5: Diode [Image Source]

A. Composition

As mentioned earlier, there are two types of diodes: vacuum diodes and semiconductor diodes. A
vacuum diode consists of two electrodes (cathode and anode) placed inside a sealed vacuum glass tube.
A semiconductor diode comprises p-type and n-type semiconductors. It is, therefore, known as a p-n
junction diode. It is usually made of silicon, but you can also use germanium or selenium.

B. How Does It Work?

Vacuum Diode
When the cathode is heated by a filament, an invisible cloud of electrons, called space charge, forms in
the vacuum. Though electrons are emitted from the cathode, the negative space charge repels them. As
electrons can’t reach the anode, no current flows through the circuit. However, when the anode is made
positive, the space charge vanishes. As a result, current starts flowing from the cathode to the anode.
Thus, electric current within the diode flows only from the cathode to the anode and never from the
anode to the cathode.

P-N Junction Diode

A p-n junction diode comprises p-type and n-type semiconductors of silicon. The p-type semiconductor
is usually doped with boron, leaving holes (positive charge) in it. The n-type semiconductor, on the other
hand, is doped with antimony, adding a few extra electrons (negative charge) in it. So, electric current
can flow through both semiconductors.

When you put p-type and n-type blocks together, the extra electrons from the n-type combine with the
holes in the p-type, creating a depletion zone without any free electrons or holes. In short, current can
no longer pass through the diode.

When you connect the battery’s negative terminal to the n-type silicon and the positive terminal to p-
type (forward-bias), current starts to flow as electrons and holes can now move across the junction.
However, if you reverse the terminals (reverse-bias), no current flows through the diode because holes
and electrons are pushed away from each other, widening the depletion zone. So, just like a vacuum
diode, a junction diode can also allow current to pass in one direction only.

C. Function and Significance

Though diodes are one of the simplest components in an electronic circuit, they have unique
applications across industries.

AC to DC Conversion

The most common and important application of a diode is the rectification of AC power to DC power.
Usually, a half-wave (single diode) or a full-wave (four diodes) rectifier is used to convert AC power into
DC power, particularly in household power supply. When you pass AC power supply through a diode,
only half the AC waveform passes through it. As this voltage pulse is used to charge the capacitor, it
produces steady and continuous DC currents without any ripples. Different combinations of diodes and
capacitors are also used to build various types of voltage multipliers to multiply a small AC voltage into
high DC outputs.

Bypass Diodes

Bypass diodes are often used to protect solar panels. When the current from the rest of the cells passes
through a damaged or dusty solar cell, it causes overheating. As a result, the overall output power
decreases, creating hot spots. The diodes are connected parallel to the solar cells to protect them
against this overheating problem. This simple arrangement limits the voltage across the bad solar cell
while allowing the current to pass through undamaged cells to the external circuit.

Voltage Spike Protection

When the power supply is suddenly interrupted, it produces a high voltage in most inductive loads. This
unexpected voltage spike can damage the loads. However, you can protect expensive equipment by
connecting a diode across the inductive loads. Depending on the type of security, these diodes are
known by many names including snubber diode, flyback diode, suppression diode, and freewheeling
diode, among others.

Signal Demodulation

They are also used in the process of signal modulation because diodes can remove the negative element
of an AC signal efficiently. The diode rectifies the carrier wave, turning it into DC. The audio signal is
retrieved from the carrier wave, a process called audio-frequency modulation. You can hear the audio
after some filtering and amplification. Hence, diodes are commonly found in radios to extract the signal
from the carrier wave.

Reverse Current Protection

Reversing polarities of a DC supply or incorrectly connecting the battery can cause a substantial current
to flow through a circuit. Such a reverse connection can damage the connected load. That’s why a
protective diode is connected in series with the positive side of the battery terminal. The diode becomes
forward-biased in the case of correct polarity and the current flows through the circuit. However, in the
event of a wrong connection, it becomes reverse-biased, blocking the current. Thus, it can protect your
equipment from potential damage.
Component 4: Transistor

One of the most crucial components of an electronic circuit, transistors have revolutionized the field of
electronics. These tiny semiconductor devices with three terminals have been around for more than five
decades now. They are often used as amplifiers and switching devices. You can think of them as relays
without any moving parts because they can turn something ‘on’ or ‘off’ without any movement.

Figure 6: Transistors [Image Source]

A. Composition

In the beginning, Germanium was used to build transistors which were extremely temperature-sensitive.
Today, however, they are made from Silicon, a semiconductor material found in the sand because
Silicon transistors are much more temperature-tolerant and cheaper to manufacture. There are two
different types of Bipolar Junction Transistors (BJT), NPN and PNP. Each transistor has three pins called
Base (b), collector (c), and emitter (e). NPN and PNP refer to the layers of semiconductor material used
to make the transistor.

B. How Does It Work?

When you sandwich a p-type silicon slab between two n-type bars, you get an NPN transistor. The
emitter is attached to one n-type, while the collector is attached to the other. The base is attached to
the p-type. The surplus holes in the p-type silicon act as barriers, blocking the flow of the current.
However, if you apply a positive voltage to the base and the collector and negatively charge the emitter,
electrons start flowing from the emitter to the collector.

The arrangement and number of p-type and n-type blocks remain inverted in a PNP transistor. In this
type of transistor, one n-type is sandwiched between two p-type blocks. As voltage allocation is
different, a PNP transistor works differently. An NPN transistor requires a positive voltage to the base,
while a PNP requires a negative voltage. In short, the current must flow away from the base to turn a
PNP transistor on.

C. Function and Significance

Transistors function as both, switches and amplifiers in most electronic circuits. Designers often use a
transistor as a switch because unlike a simple switch, it can turn a small current into a much larger one.
Though you can use a simple switch in an ordinary circuit, an advanced circuit may need varying
amounts of currents at different stages.

Transistors in Hearing Aids

One of the most well-known applications of transistors is the hearing aid. Usually, a small microphone in
the hearing aid picks up the sound waves, converting them into fluctuating electrical pulses or currents.
When these currents pass through a transistor, they are amplified. The amplified pulses then pass
through a speaker, converting them into sound waves once again. Thus, you can hear a substantially
louder version of the surrounding noise.

Transistors in Computers and Calculators

We all know that computers store and process information using the binary language of “zero” and
“one.” However, most people don’t know that transistors play a critical role in making something called
logic gates, which are the backbones of computer programs. Transistors are often hooked up with logic
gates to build a unique piece of an arrangement called a flip-flop. In this system, the transistor remains
‘on’ even if you remove the base current. It now flips on or off whenever new current passes through it.
Thus, a transistor can store a zero when it’s off or a one when it’s on, which is the working principle of
computers.

Darlington Transistors

A Darlington transistor is made of two PNP or NPN polar junction transistors placed together. It is named
after its inventor Sidney Darlington. The sole purpose of a Darlington transistor is to deliver a high
current gain from a low base current. You can find these transistors in instruments that require a high
current gain at a low frequency such as power regulators, display drivers, motor controllers, light and
touch sensors, alarm systems, and audio amplifiers.

IGBT and MOSFET Transistors

The Insulated-Gate Bipolar Transistor (IGBT) transistors are often used as amplifiers and switches in
various instruments including electric cars, trains, refrigerators, air-conditioners, and even stereo
systems. On the other hand, Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFET) are
commonly used in integrated circuits to control a device’s power levels or for storing data.
Component 5: Inductor

An inductor, also known as a reactor, is a passive component of a circuit having two terminals. This
device stores energy in its magnetic field, returning it to the circuit whenever required. It was discovered
that when two inductors are placed side by side without touching, the magnetic field created by the first
inductor affects the second inductor. It was a crucial breakthrough that led to the invention of the first
transformers.

Figure 7: Inductors [Image Source]

A. Composition

It is probably the simplest component, comprising just a coil of copper wire. The inductance is directly
proportional to the number of turns in the coil. Sometimes, however, the coil is wound around a
ferromagnetic material such as iron, laminated iron, and powdered iron to increase the inductance. The
shape of this core can also increase the inductance. Toroidal (donut-shaped) cores provide better
inductance compared to solenoidal (rod-shaped) cores for the same number of turns. Unfortunately, it is
difficult to join inductors in an integrated circuit, so they are usually replaced by resistors.

B. How Does It Work?

Whenever the current passes through a wire, it creates a magnetic field. However, the unique shape of
the inductor leads to the creation of a much stronger magnetic field. This powerful magnetic field, in
turn, resists alternating current, but it lets direct current flow through it. This magnetic field also stores
energy.

Take a simple circuit comprising a battery, a switch, and a bulb. The bulb will glow brightly the moment
you turn the switch on. Add an inductor to this circuit. As soon you turn the switch on, the bulb changes
from bright to dim. On the other hand, when the switch is turned off, it becomes very bright, just for a
fraction of a second before turning off completely.

As you turn the switch on, the inductor starts using the electricity to create a magnetic field, temporarily
blocking the current flow. But, only DC current passes through the inductor as soon as the magnetic field
is complete. That’s why the bulb changes from bright to dim. All this time, the inductor stores some
electrical energy in the form of magnetic field. So, when you turn the switch off, the magnetic field
keeps the current in the coil steady. Thus, the bulb burns brightly for a while before turning off.

C. Function and Significance

Though inductors are useful, it is difficult to incorporate them into electronic circuits due to their size. As
they are bulkier compared to other components, they add a lot of weight and occupy plenty of space.
Hence they are usually replaced by resistors in integrated circuits (ICs). Still, inductors have a wide range
of industrial applications.

Filters in Tuned Circuits

One of the most common applications of inductors is to select the desired frequency in tuned circuits.
They are used extensively with capacitors and resistors, either in parallel or series, to create filters. The
impedance of an inductor increases as the frequency of signal increases. Thus, a stand-alone inductor
can only act as a low-pass filter. However, when you combine it with a capacitor, you can create a
notched filter because the impedance of a capacitor decreases as the frequency of signal increase. So,
you can use different combinations of capacitors, inductors, and resistors to create various types of
filters. They are found in most electronics including televisions, desktop computers, and radios.

Inductors as Chokes

If an alternate current flows through an inductor, it creates an opposite current flow. Thus, it can
convert an AC supply into a DC. In other words, it chokes the AC supply but allows the DC to pass
through it, hence the name ‘choke.’ Usually, they are found in power supply circuits that need to
convert AC supply to DC supply.

Ferrite Beads

A ferrite bead or ferrite choke is used to suppress high-frequency noise in electronic circuits. Some of
the common uses of ferrite beads include computer cables, television cables, and mobile charge cables.
These cables can, sometimes, act as antennas, interloping with audio and video output of your television
and computer. So, inductors are used in ferrite beads to reduce such radio frequency interference.
Inductors in Proximity Sensors

Most proximity sensors work on the principle of inductance. An inductive proximity sensor comprises
four parts including an inductor or coil, an oscillator, a detection circuit and an output circuit. The
oscillator generates a fluctuating magnetic field. Whenever an object comes into the proximity of this
magnetic field, eddy currents start to build up, reducing the sensor’s magnetic field.

The detection circuit determines the strength of the sensor, while output circuit triggers the appropriate
response. Inductive proximity sensors, also called contactless sensors, are cherished for their reliability.
They are used at traffic lights to detect the traffic density and also as parking sensors in cars and trucks.

Induction Motors

An induction motor is probably the most common example of the application of inductors. Usually, in an
induction motor, inductors are placed in a fixed position. In other words, they are not allowed to align
with the nearby magnetic field. An AC power supply is used to create a rotating magnetic field which
then rotates the shaft. The power input controls the speed of rotation. Hence, inductions motors are
often used in fixed speed applications. The induction motors are very reliable and robust because there
is no direct contact between the motor and the rotor.

Transformers

As mentioned earlier, the discovery of inductors led to the invention of transformers, one of the
fundamental components of power transmission systems. You can create a transformer by combining
the inductors of a shared magnetic field. They are usually used to increase or decrease voltages of the
power lines to the desired level.

Energy Storage

Just like a capacitor, an inductor can also store energy. However, unlike a capacitor, it can store energy
for a limited time. As the energy is stored in a magnetic field, it collapses as soon as the power supply is
removed. Still, inductors function as reliable energy storage device in switch mode power supply such as
desktop computers.

Component 6: Relay
A relay is an electromagnetic switch that can open and close circuits electromechanically or
electronically. You need a relatively small current to operate a relay. Usually, they are used to regulate
low currents in a control circuit. However, you can also use relays to control high electric currents. A
relay is the electrical equivalent of a lever. You can switch it on with a small current to turn on (or
leverage) another circuit using large current. Relays are either electromechanical relays or solid-state
relays.

Figure 8: Relays [Image Source]

A. Composition

An Electromechanical Relay (EMR) comprises a frame, coil, armature, spring, and contacts. The frame
supports various parts of the relay. The armature is the moving part of a relay switch. A coil (mostly
copper wire), wound around a metal rod generates a magnetic field that moves the armature. Contacts
are the conducting parts that open and close the circuit.

A Solid-State Relay (SSR) consists of an input circuit, a control circuit, and an output circuit. The input
circuit is the equivalent of a coil in an electromechanical relay. The control circuit acts as a coupling
device between input and output circuits, while the output circuit performs the same function as the
contacts in an EMR. Solid-state relays are becoming increasingly popular as they are cheaper, faster, and
reliable compared to electromechanical relays.

B. How Does It Work?

Whether you are using an electromechanical relay or a solid-state relay, it is either a Normally Closed
(NC) or a Normally Opened (NO) relay. In case of an NC relay, the contacts remain closed when there is
no power supply. However, in a NO relay, the contacts remain open when there is no power supply. In
short, whenever current flows through a relay, the contacts will either open or close shut.

In an EMR, power supply energizes the relay coil, creating a magnetic field. The magnetic coil attracts a
ferrous plate mounted on the armature. When the current stops, the armature is released into its
resting position by spring action. An EMR can also have single or multiple contacts within a single
package. If a circuit uses only one contact, it is called a Single Break (SB) circuit. A Double Break Circuit
(DB), on the other hand, comes with tow contacts. Usually, single break relays are used to control low
power devices such as indicator lamps, while double break contacts are used to regulate high-power
devices such as solenoids.

When it comes to operating an SSR, you need to apply a voltage higher than the specified pickup voltage
of the relay to activate the input circuit. You have to apply a voltage less than the stipulated minimum
dropout voltage of the relay to deactivate the input circuit. Control circuit transfers the signal from the
input circuit to the output circuit. The output circuit switches on the load or performs the desired action.

C. Function and Significance

As they can control a high current circuit by a low current signal, most control processes use relays as
the primary protection and switching devices. They can also detect fault and irregularities occurring in
the power distribution systems. Typical applications include telecommunication, automobiles, traffic
control systems, home appliances, and computers among others.

Protective Relays

Protective relays are used to trip or isolate a circuit if any irregularities are detected. Sometimes, they
can also set off alarms when a fault is detected. Types of protection relays depend on their function. For
example, an overcurrent relay is designed to identify the current exceeding a predetermined value.
When such current is detected, the relay operates tripping a circuit breaker to protect the equipment
from potential damage.

A distance relay or impedance relay, on the other hand, can detect abnormalities in the ratio of current
and voltage rather than monitoring their magnitude independently. It swarms into action when the V/I
ratio falls below a predetermined value. Usually, protective relays are used to protect equipment such
as motors, generators, and transformers, and so on.

Automatic Reclosing Relay

An automatic reclosing relay is designed to cause multiple reclosures of a circuit breaker that is already
tripped by a protective relaying. For example, when there is a sudden voltage drop, the electrical circuit
in your home may experience several brief power outages. These outages occur because a reclosing
relay is trying to switch on the protective relay automatically. If it succeeds the power supply will be
restored. If not, there will be a complete blackout.
Thermal Relays

The thermal effect of electrical energy is the working principle of a thermal relay. In short, it can detect
the rise the ambient temperature and switch on or off a circuit accordingly. It consists of a bimetallic
strip which heats up if an overcurrent passes through it. The heated strip bends and closes the No
contact, tripping the circuit breaker. The most common application of thermal relay is overload
protection of electric motor.

Component 7. Quartz Crystal

Quartz crystals have several applications in the electronics industry. However, they are mostly used as
resonators in electronic circuits. Quartz is a naturally occurring form of silicon. However, it is now
produced synthetically to meet the growing demand. It exhibits the piezoelectric effect. If you apply
physical pressure on one side, the resulting vibrations generate an AC voltage across the crystal. Quartz
crystal resonators are available in many sizes according to the required applications.

Figure 9: Quartz Crystal [Image Source]

A. Composition

As mentioned earlier, quartz crystals are either synthetically manufactured or occur naturally. They are
often used to make crystal oscillators to create an electrical signal with a precise frequency. Usually, the
shape of quartz crystals is hexagonal with pyramids at ends. However, for practical purposes, they are
cut into rectangular slabs. The most common types of cutting formats include X cut, Y cut, and AT cut.
This slab is placed between two metal plates called holding plates. The outer shape of a quartz crystal or
crystal oscillator can be cylindrical, rectangular or square.

B. How Does It Work?

If you apply an alternating voltage to a crystal, it causes mechanical vibrations. The cut and the size of
the quartz crystal determine the resonant frequency of these vibrations or oscillations. Thus, it
generates a constant signal. Quartz oscillators are cheap and easy to manufacture synthetically. They are
available in the range from a few KHz to a few MHz. As they have a higher quality factor or Q factor,
crystal oscillators are remarkably stable with respect to time and temperature.
C. Function and Significance

The exceptionally high Q factor enables you to use quartz crystals and the resonant element in
oscillators as well as filters in electronic circuits. You can find this highly reliable component in radio
frequency applications, as oscillator clock circuits in microprocessor boards, and as a timing element in
digital watches as well.

Quartz Watches

The problem with traditional coil spring watches is that you have to keep winding the coil periodically.
Pendulum watches, on the other hand, depend on the force of gravity. Thus, they tell time differently at
different sea levels and altitudes due to changes in the gravitational force. The performance of quartz
watches, however, is not affected by any of these factors. Quartz watches are battery-powered. Usually,
a tiny crystal of quartz regulates the gears that control the second, the minute, and the hour hands. As
quartz watches use very little energy, the battery can often last longer.

Filters

You can also use quartz crystals in an electronic circuit as filters. They are often used to filter out
unwanted signals in radios and microcontrollers. Most basic filters consist of a single quartz crystal.
However, advanced filters may comprise more than one crystal to match the performance
requirements. These quartz crystal filters are far superior to the ones manufactured using LC
components.

Conclusion

From communicating with your loved ones living across continents to making a hot cup of coffee,
electronic gadgets touch almost every aspect of our lives. However, what makes these electronic
gadgets finish seemingly time-consuming tasks in just a few minutes? Tiny electronic circuits are the
foundation of all electronic equipment. Reading about the various components of an electronic circuit
will help you understand their function and significance. Do share your suggestions and views about this
in the comments section below.

IoT is a platform to connect the things which have an internet. A connected device is a complex solution,
with various potential entry doors for an attacker. A connected device pentest IoT includes tests on the
entire object ecosystem. That is electronic layer, embedded softwares, communications protocol,
servers, web and mobile interface. The pentest on the electrical side,embedded softwares, and
communication protocol concern vulnerabilities more specifically the IoT.

There are three types of attacks on connected objects and embedded systems. Software attack, non-
invasive and invasive hardware attacks. The first take advantage of software vulnerabilities, the second
recover information from the hardware without damaging it while the third involve opening the
components and therefore destroying them in order to be able to extract secrets. While the first two
types of attacks do not require many resources, this is not thecase for invasive attacks, for which very
expensive equipment is requires.

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I'm interested in developing a new way to deal with the energy.

I know there are UNIVERSITY courses that teach how to develop new components but it is just a way
modifying them (turning around like playing with the instruments that we already have) turning them in
'disassembling their duties' while the basis is always the same.

Just to give you an idea of what I want.

We live on planet Earth and we are ‘carbon-based lives, subject to a 'carbon oxide' living.

We have made a step in developing AI ( Artificial Intelligence) and Bionic. Both of them represent an
extreme high level of quality of results, but it is just a co-operation (instead of transformation) of our
living matter with the support of an electronic circuit that (try to understand me) replace the ‘living
organ’ until it will go.

We don’t know why .... it is just work out like in a test of a circuit.
The basis are anyway based on the same foundation of using energy in the electronic circuit. The mother
board is the foundation of the Bionic. It has just moved from the electronic (single component for a
single impulse (task) to a digital circuit (a shell that include a myriad of single components) .... but the
basis are always the same.

We have discovered the STEM CELLS, and we know that if we are not able to stop the growth the result
work out in a failure.

So, everything we've found is very interesting but it highlight that we haven’t been able yet to reach a
knowledge to decide when to start, to rest, to stop or change something: WE ARE JUST RIDING A
MOTHER BOARD impulse that generate children that attend every decade a new university degree that
change the image but not the result: they are just about only a sum of ‘giving try' that move one here
and the other time there ..... but we are just GALOPPING on the impulse castrated inside the mother
board in the only way it is happened to us to do it. It was a test and something that happened.... only
that..... On top of this we have just added new accessories .... nothing else ... .

I like to compare things to better understand.

Now, can you please tell me how can we do if the Planet Earth will shift (as it is always occurring every
some millions of years) to another terrestrial polarity?

It looks like that on this shift esoteric minds we'll be able to retrieve info from Ancient Super Intelligent
Civilizations that on this today polarity it is not possible to reach with our neural neurons OUTPUT. I say
output because the neural and neurons have the knowledge but not the local and external environment
to function ..... Now if we are good builder of technology we should know what is the obstacle, isn’t it?

Can you please tell me if we'll be still in need of Bionic tools to survive or our minds under that kind of
particular energy generated from this shift will cause a clearing of our ignorance in each one of us? I
mean just dissipating like a mica the fumes and heat that confiscate the labour of a hardware (our
brain)?
What we'll be in us the change in our neural path for the Bionic?

Now, I have always tried to understand between practical existence (creating circuits: electronic, digital,
mechanical etc) but have you never thought the job of Large Hadron Collider in Geneva in Swetzerland?

Don’t you think that all those new particles represent nothing less that the functioning of the Universe?
Each particle is just a mechanical-electro-digital component that belong to a special mother board: the
mindfulness?

If you notice each new particles decay, exactly like the mindfulness mind on rest .

Maybe we have to work there thinking that the texture of the Universe is a mother board with a circuit
with movable partitions (components) according to the necessity of generating primordial blast of living
alchemies that will become matter etcetcetc .... until the death will come and we start again.

In this case we should try to work on continuous shift between components or we should create
components that don’t allow flowing energy but alchemies ...

It will be maybe much clear even for the workers at the Large Collider trying to understand that their
research will never have an end because ... just because it is a deal with the Universe .... the Universe is
a piezo-component (only one) able to generate lives regenerating deaths ..... while only working on
alchemies .... to them forming matter that will make again alchemies and so on.....

So, are we able to develop a mother board with a unique component working in multi-tasks but able to
support its alchemies generated from other alchemies??? From fumes to evaporation ... from
evaporation to fumes .... start to reach to the mindfulness moment to cease the sickness (or error in the
body) and start again?

I still have a lot to say about this .... but I don’t know if you can understand me ...

Like a mother give birth to a baby, the birth represent the decease of the cancer to release a new life
that will keep up the life of the mother......

How could we call instead the job of the father? What component will represent the task of the father (a
stellar collision, a nucleosy stellar, ) .... even in this act there is just an impulse (to create alchemies or
fumes) but not the attachment .... The role of the father is just to give life and then retrieve peacefully (a
complete act of minfulness) .

Let's go to analyse the 2 components (not the material genitals that are just a medium to address the
duty) but the ovul and the spermatozoa .... they are 2 components that work on energy creating a spark
with double effect: the male the wings of the universe (I go and come into you) and the mother the
roots of the planet ... (the mental attachment to possess and growing) ..... 2 components completely
different ... that will never agree on anything except in that moment of the reproduction. ..

But be careful..... when I say they will agree in that moment, I mean they are able to leave their guard
off, reaching a mindfulness moment of union, merging that ‘MOMENTUM' that is the beginning of every
action of keeping up.

After that .... each one will move back inside their shell to continue ‘alone'.

We can discuss for hours about this what do you think.