An electronic component is any basic discrete device or physical entity in an electronic system used to affect electrons or their associated fields.
Electronic components have a number of electrical terminals or leads. These leads connect to other electrical components, often over wire, to create an electronic circuit with a particular function (for example an amplifier, radio receiver, or oscillator). Basic electronic components may be packaged discretely, as arrays or networks of like components, or integrated inside of packages such as semiconductor integrated circuits, hybrid integrated circuits, or thick film devices.
Classification
Active Components
Common example of Active components
Transistors
A transistor is a semiconductor device used to amplify and switch electronic signals and power. A voltage or current applied to one pair of the transistor’s terminals changes the current through another pair of terminals.
A transistor has at least three terminals for connection with an external circuit, namely: Collector, Emitter and Base.
There are two types of transistors:
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Bipolar Junction Transistor (BJT)
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Field-effect transistor (FET)
Passive Components
Passive components can't introduce net energy into the circuit. They only make use of the energy available from the (AC) circuit they are connected to. As a consequence they can't amplify (increase the power of a signal), although they may increase a voltage or current (such as is done by a transformer or resonant circuit). They do not require external source to operate. Passive components include two-terminal components such as resistors, capacitors, inductors, and transformers.
Common examples of passive components:
Inductors
Basic Electronic Components
Introduction
An electronic component is any basic discrete device or physical entity in an electronic system used to affect electrons or their associated fields.
Electronic components have a number of electrical terminals or leads. These leads connect to other electrical components, often over wire, to create an electronic circuit with a particular function (for example an amplifier, radio receiver, or oscillator). Basic electronic components may be packaged discretely, as arrays or networks of like components, or integrated inside of packages such as semiconductor integrated circuits, hybrid integrated circuits, or thick film devices.
Classification
Electronic components can be classified majorly as active and passive components. The strict physics definition treats passive components as ones that cannot supply energy themselves, whereas a battery would be seen as an active component since it truly acts as a source of energy.
Active Components
Active components are those that produce or deliver energy (usually from a DC source) to a circuit. They require external source for operation. They are capable of power gain and can control the flow of current in a circuit. Active components include amplifying components such as transistors, triode vacuum tubes (valves), and tunnel diodes. Common example of active components includes diodes, transistors, ICs, SCRs etc.
Diodes
A diode is a semiconductor device that essentially acts as a one-way switch for current. It allows current to flow easily in one direction, but severely restricts current from flowing in the opposite direction. When a diode allows current flow, it is forward-biased. When a diode is reverse-biased, it acts as an insulator and does not permit current to flow.
Common types of diodes include: Gunn Diode, Laser diode, Light emitting diodes, Photodiode, PIN diode, PN Junction, Schottky diodes, Step recovery diode, Tunnel diode and a Zener diode. Diodes can be used as rectifiers, signal limiters, voltage regulators, switches, signal modulators, signal mixers, signal demodulators, and oscillators.
Transistors
A transistor is a semiconductor device used to amplify and switch electronic signals and power. A voltage or current applied to one pair of the transistor’s terminals changes the current through another pair of terminals.
A transistor has at least three terminals for connection with an external circuit, namely: Collector, Emitter and Base.
There are two types of transistors:
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Bipolar Junction Transistor (BJT):
Negative Positive Negative (NPN BJT)
Positive Negative Positive (PNP BJT)
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Field-effect transistor (FET)
Junction (JFET)
Metal-Oxide Semiconductor (MOSFET)
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BJT are useful as amplifiers while FET are applied in motor drivers.
Integrated Circuits
An integrated circuit (IC) is a set of transistors integrated on a single chip. They act as the brain of an electronic circuit. Modern microprocessor ICs can have billions of transistors per square inch.​
ICs operate by switching billions of transistors very quickly. To figure out what a specific IC does, you need to check its datasheet. The datasheet is a complete documentary of a particular IC. Just search for the name of the 'chip name' + 'datasheet' e.g. “Cd4047 datasheet” in Google
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As discussed above, the IC being the brain of the electronic circuit can be used to complete simpler and discrete jobs, example; taking a voltage input and outputs commands to a motor. IC makes it much easier to make advanced projects with less components.
SCR
A silicon controlled rectifier or semiconductor controlled rectifier is a four-layer solid-state current-controlling device. Some sources define silicon-controlled rectifiers and thyristors as synonymous, other sources define silicon-controlled rectifiers as a proper subset of the set of thyristors, those being devices with at least four layers of alternating n- and p-type material. According to Bill Gutzwiller, the terms "SCR" and "controlled rectifier" were earlier, and "thyristor" was applied later, as usage of the device spread internationally.
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SCRs are unidirectional devices (i.e. can conduct current only in one direction) as opposed to TRIACs, which are bidirectional (i.e. charge carriers can flow through them in either direction). SCRs can be triggered normally only by currents going into the gate as opposed to TRIACs, which can be triggered normally by either a positive or a negative current applied to its gate electrode.
SCRs are mainly used in devices where the control of high power, possibly coupled with high voltage, is demanded. Their operation makes them suitable for use in medium- to high-voltage AC power control applications, such as lamp dimming, power regulators and motor control.
SCRs and similar devices are used for rectification of high-power AC in high-voltage dc power transmission. It is used as switch in various devices. Early Solid-State Pinball machines made use of these to control lights, solenoids, and other functions digitally, instead of mechanically, hence the name, Solid-state.
Passive Components
Passive components can't introduce net energy into the circuit. They make use of the energy available from the (AC) circuit they are connected to. As a consequence they can't amplify (increase the power of a signal), although they may increase a voltage or current (such as is done by a transformer or resonant circuit). They do not require external source to operate. Passive components include two-terminal components such as resistors, capacitors, inductors, transformers etc.
Resistors
A resistor impedes the flow of current through a circuit. As the name implies, resistors are used to resist (control) the voltages and currents in the circuit. Let’s say you wish to connect an LED to a 9V battery, if the LED is connected directly to the battery, too much will flow through the LED leading to heat and eventually damage the LED in a short while.
Inductors
An inductor is a device that stores electrical energy in a magnetic field. An inductor is a coil of wire. If you wind a coil of wire into a coil, you have simply created an inductor. when a current is applied through the coil (connecting it to a power source), a magnetic field is created around it, and this field stores energy.
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When the current through the inductor remains the same, the inductor simply allows current to pass through, just like it was a normal wire. But when the current through the inductor changes, the built-up energy in the magnetic field resists this change by changing the resistance of the inductor.
The change in resistance is actually useful in creating a filter to reduce noise in filter circuits.
Inductors are often used in filters and oscillators; example in radio equipment.
Capacitors
A capacitor a device that is used to store electrical charge. It consists of one or more pairs of conductors separated by an insulator (dielectric). They are used for filtering power supply lines, tuning resonant circuits, and for blocking DC signals, among numerous other uses.
Transformers
Transformers are electrical devices consisting of two or more coils of wire used to transfer electrical energy by means of a changing magnetic field.
The Transformer can be thought of more as an electrical component rather than an electronic component. A transformer basically is very simple static (or stationary) electro-magnetic passive electrical device that works on the principle of Faraday’s law of induction by converting electrical energy from one value to another.
A transformer operates on the principals of “electromagnetic induction”, in the form of Mutual Induction. Mutual induction is the process by which a coil of wire magnetically induces a voltage into another coil located in close proximity to it. Then we can say that transformers work in the “magnetic domain”, and transformers get their name from the fact that they “transform” one voltage or current level into another.
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Transformers are capable of either increasing or decreasing the voltage and current levels of their supply, without modifying its frequency. This feature makes it useful for stepping up voltage for long distance transmission and stepping down voltage that can be used to supply electrical equipment in our homes and workplaces.