Introduction
Electronic components, which are basic elements in electronic circuits, are usually individual packages and have two or more leads or metal contacts. An electronic component is any basic discrete device or physical entity in an electronic system used to affect electrons or their associated fields. They shall be connected to each other to form an electronic circuit with specific functions, such as amplifiers, radio receivers, oscillators, etc. One of the common ways to connect electronic components is to weld to a PCB. Electronic components have many shapes and sizes, such as resistors, capacitors, inductors, transistors, diodes, etc.) or special set like integrated circuits. All of them are belong to two types: active components and passive components. Here may be a question: what is the difference between active and passive component? This note is tell the differences between them.
Active vs Passive Components
Catalog
Ⅰ What is Meant by Active Components?
1.1 Active Components Definition
A active component is a part of a circuit that rely on an external power source to control or modify electrical signals. They include amplifying components such as transistors, dc generators, triode vacuum tubes (valves), tunnel diodes, silicon controlled rectifiers, etc.
1.2 Active Components Example
A transistor is a active semiconductor component for amplifying, controlling, and generating electrical signals, just like a diode. It consists of two PN diodes connected back to back, and has three terminals namely emitter, base and collector. The primary transistor is the BJT and FET is the modern version of transistor.
A vacuum tube, an electron tube, or valve, or a tube, is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied. Vacuum tubes contain electrodes for controlling electron flow and were used in early computers as a switch, an amplifier or display screen (CRT). Used as on/off switches, vacuum tubes allowed the first computers to perform digital computations. One disadvantage of it is the cost of tubes are now much more expensive and tube amplifiers require much point to point wiring. In addition, tube hardware is now more expensive.
- Silicon Controlled Rectifiers (SCRs)
A silicon controlled rectifier (SCR) or semiconductor-controlled rectifier is a four-layer solidstate current-controlling device. It is one of several power semiconductor devices along with Triacs (Triode AC's), Diacs (Diode AC's) and UJT's (Unijunction), functioning as an electrical switch for high power operations.There are three modes of operation for an SCR, including forward blocking mode (off state), forward conduction mode (on state), reverse blocking mode (off state).
Ⅱ What is Meant by Passive Components?
2.1 Passive Components Definition
A passive element is an electrical component that does not generate power, but instead dissipates, stores, and/or releases it. For example, passive components like resistors, transformers, capacitor, inductor, and diodes don't need an external power source to function. These components use some other property to control the electrical signal.
2.2 Passive Components Example
A resistor is a passive two-terminal electrical component. Since "the main function of the resistor is to block the flow of current", it can be inferred that the resistor is a "current limiting component." We usually define a resistor as a two-terminal electronic component made of a resistive material and having a certain structural form that can restrict the passage of current in the circuit. The effect of the conductor on the current is called resistance, and is represented by the symbol R. The unit is ohm, kiloohm, and megaohm, which are represented by Ω, KΩ, and MΩ, respectively. Carbon Resistors are the most common type of Composition Resistors. Carbon resistors are a cheap general purpose resistor used in electrical and electronic circuits. In addition, They are the standard E3, E6, E12, E24, E48 and E96 resistor values. The E3 series resistors are the most widely used and hence these values will be the most common resistor values used within the electronics industry.
A capacitor (originally known as a condenser) is a passive two-terminal electrical component. A capacitor is a device that is used to store charges between its plates in an electrical circuit. It works on the principle that the capacitance of a conductor increases appreciably when an earthed conductor is brought near it. In circuits, capacitors such as aluminum electrolytic capacitors, filter capacitors, tantalum capacitors, and chip ceramic capacitors are often seen. Many suppliers have evolved a series of standard capacitor values in their capacitor products.
A diode is defined as a two-terminal electronic component with unidirectional conduction. In other words, it only conducts current in one direction. There are electronic diodes and crystal diodes. Most common and commonly used are crystal diodes. The unidirectional conduction characteristic of diodes are used in almost all electronic circuits, and it plays an important role in many circuits. An ideal diode will have zero resistance in one direction, and infinite resistance in the reverse direction.
An inductor is a passive electronic component in many switched-mode power supplies to produce DC current. It uses a conductor that is wound into a coil, and when electricity flows into the coil from the left to the right, this will generate a magnetic field in the clockwise direction. Typically, an inductor consists of an insulated wire wound into a coil. The inductor supplies energy to the circuit to keep current flowing during the "off" switching periods and enables topographies where the output voltage is higher than the input voltage. Basic types of inductor include air-core inductor, iron-core inductor, toroidal tnductors, laminated core inductors, powdered iron core inductors, etc. At present, the most common application of transistors today is for computer memory chips, including solid-state multimedia storage devices for electronic games, cameras, and MP3 players—and microprocessors, where millions of components are embedded in a single integrated circuit.
Ⅲ Differences between Active and Passive Components Overview
Now that we have understood the Active and Passive devices and their forms, let us make a comparison based on certain parameters between active and passive components, as described below.
Energy Source: Active components need an external source of energy. No extra source of energy is needed for their operation in the case of passive components. Without the need for a particular voltage, a resistor operates on its own.
Energy: Active components create energy in the form of voltage or current, but passive components are devices that store energy, such as a capacitor, store its energy in the form of an electric field, and store its energy in the form of a magnetic field in an inductor.
External Source: As seen earlier, active components need an extra source to monitor and manage their operations, but there is no requirement for an additional source in the case of passive components.
Linearity: Linear components are passive and non-linear components are active. The voltage drop across would be linear to its resistance value according to Ohm’s law in a passive component like a resistor. The performance will have an amplification factor that will not be linear in a transistor or other active pieces.
Power Gain: Active components are capable of delivering power gain, however, it is not available in the case of passive components.
Controlling the Current: As the name suggests, an active component may easily regulate the current flow, while a passive component may not do the same process.
Ⅳ Conclusion
Components can be classified as passive, active, or electromechanic. According to the science and technology of all types of electronic components issued by suppliers, you can select a better one for your circuit requirements.
Frequently Asked Questions about Active and Passive Components
1. Which are passive components?
A passive component is an electronic component which can only receive energy, which it can either dissipate, absorb or store it in an electric field or a magnetic field.
Common examples of passive components include: resistors, inductors, capacitors, transformers.
2. Why are resistors called passive components?
Resistors are called passive because they don't have gain or control power like semiconductors or other active devices.
3. What is difference between resistor and inductor?
Resistor mainly opposes the flow of current. Inductor mainly opposes the changes in current flowing through it.
4. Is a diode active or passive?
Components incapable of controlling current by means of another electrical signal are called passive devices. Resistors, capacitors, inductors, transformers, and even diodes are all considered passive devices.
5. Which is active component?
Active components are devices that can amplify an electric signal and produce power. Any characteristic active component will comprise an oscillator, transistor or an integrated circuit. An active component functions as an alternating current circuit in devices.
6. What is different between active and passive component in circuit?
Active electronic components are those that can control the flow of electricity. ... Passive electronic components are those that don't have the ability to control current by means of another electrical signal. Examples of passive electronic components are capacitors, resistors, inductors, transformers, and diodes.