What Are Electronic Components?
Electronic components are the basic discrete devices that form a circuit. They are the fundamental building blocks that serve a specific function, such as amplifying signals, converting energy and controlling electricity flow.
Passive components do not introduce net energy to the circuit and cannot amplify signals, but they can increase voltage or current. They include resistors, capacitors and inductors.
Types of Electronic Components
Electronic components are the building blocks of circuit designs. Without them, electronic devices wouldn’t be able to work. There are a variety of basic electronic components that all electrical circuits need, including resistors, diodes, capacitors, integrated circuits, and transistors.
Integrated circuits are the backbone of modern electronics, combining discrete components into one piece of silicon. They reduce the amount of space a device takes, save power, and increase performance. Electronic component They are the foundation of everything from microprocessors to memory chips.
Resistors are passive components that restrict the flow of electric currents by impeding the passage of electrons. They’re used to control voltage levels, set delays in a circuit, and protect other sensitive components. They are typically measured in ohms, which quantifies their resistance to the flow of electric current.
Diodes are two-terminal electronic components that allow electric currents to flow in only one direction. They’re the one-way streets of electric circuits, and they’re found in semiconductor diodes and triode vacuum tubes (valves). They have two protruding electrical connections called leads that can be soldered onto PCB traces.
Resistor
The resistor is a basic component that limits the flow of current in an electronic circuit. It also plays a critical role in the function of other components. In general, the most important property of a resistor is its resistance value. For higher precision applications other parameters may be specified, such as the temperature coefficient or unwanted inductance.
In addition, the resistor may be rated for a power rating which indicates how much heat energy it can dissipate before overheating and damaging the circuit board or other components. Larger value resistors are commonly rated in the kilo- or mega-ohm (k) range and lower valued ones in the mili-ohm (m) range.
In most applications the resistor’s resistance value is indicated with several bands of colored paint around the body of the device. Each color represents a different number and can be looked up in a resistor color code chart. Carbon composition resistors are still available, with values ranging from fraction of an ohm to 22 megohms. These are used for special purposes in old-fashioned electronics or in repair of vintage equipment.
Capacitor
Capacitors are like a miniature rechargeable battery that stores electrical energy. They’re also important because they can help to divert spurious electric signals that could otherwise cause damage to sensitive components or circuits.
The basic model of a capacitor has two thin parallel conductive plates separated by a gap, d displaystyle d and filled with a dielectric circuit chip material, which is an insulator. The bigger the plate surface area, a, and the smaller the gap between them and the higher the dielectric constant, k, the greater the capacitance.
The opposite charges on the different plates attract each other and build up until they’re equal — this is called charging the capacitor. When the capacitor is disconnected, the opposite charges start to repel each other and the capacitor discharges. Capacitors are also useful for storing the electric energy from a small current (such as from a battery) so it can be used quickly in the event of a power loss. They can even act as a kind of filter by suppressing high-frequency voltage ripples that occur when the power supply is turned on and off.
Inductor
Along with resistors and capacitors, inductors are one of the three main passive linear circuit elements. You’ll most commonly find them in power supplies as a coil of wire around a core to limit switching current and fault currents. They are also used in radio circuits arranged in a specific way to create filters and oscillators and in chokes to suppress electronic noise on power lines.
Inductors don’t like it when you change the current flowing through them. If you switch off the power, the inductor will try to fight this by pushing out electrons to stop it. It can even cause a spark if it has enough magnetic energy.
This makes them useful as an electrical current limiter and it’s this property that finds them in Snubber circuits, Overcurrent Protection and Rectifiers. Typically, they have a calculation formula represented by the symbol shown above and the more turns on the coil, the higher the inductance value. Changing the core type or increasing the coil cross-sectional area can also enhance inductance. Inductors are a little mysterious as they’re not really seen in the example circuits for beginners but you will come across them more often once you learn about other passive components such as the capacitor.
Transistor
Probably the most important invention of the 20th century, the transistor allows electronic signals to be amplified and switched on and off. It is found in every electronic device, from the microchips in a cell phone to the spacecraft in orbit around Earth.
The transistor is made of semiconductor material with at least three terminals that connect to a circuit. One layer is called the emitter and is heavily doped to push free electrons away from itself. The base is a thin layer that is lightly doped and acts to control the flow of electrons across the emitter-base junction. The collector is the right side of the transistor and is larger than the emitter to be able to handle high current flows.
The transistor can be configured to offer different types of current gain by using its base, emitter and collector connections. By looking at the characteristics of a transistor, we can see how it affects current when the input voltage changes. This helps us understand its amplification and switching capabilities. It also helps to know what type of transistor we are using in a circuit so that we can design the right configurations for it.
