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ElProCus - Electronic Projects for Engineering Students

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Electronics is a branch of an engineering, which deals with electronic and electrical circuits like Integrated circuits, Transmitters, and Receiver etc. The electronic circuit is defined as it is a combination of various electronic components that allow the flow of electric current. The electronic components consist of two or more terminals, that are used to connect one component to another component to design a circuit diagram. The electronic components are soldered on circuit boards to make a system. If you want to focus on core side projects like electronics/ electrical, you should know the basic concepts of electronic circuit symbols and their usage. This article gives an overview of electronic circuit symbols with their functionality.

Electronic Circuit Symbols

The electronic circuit symbols mainly involve wires, power supplies, resistors, capacitors, diodes, transistors, meters, switches, sensors, logic gates, audio devices, and other components.

Wires

A wire is a two terminal, single and flexible material, that allows the flow of power through it. These are mainly used to connect the power supplies to the PCB( Printed Circuit Board) and in between the components. The different types of wires will be as

Wires: A single wire with two terminals will pass the current from one component to another.
Wires Jointed: When two or more wires are connected with each other that is called as wires jointed. The joining or shorted of wires at one point is indicates the "blob".
Wires not Jointed: In complex circuit diagrams, some wires may not connect with others, in this case, bridging is commonly utilized.

Power Supplies

A Power supply/ power supply unit is an electronic device, that supplies electric energy to an electrical load. The flow of an electric current will be measured in terms of Watts. The function of the power supply is, it converts energy from one form to another according to our requirement. The various types of power supplies are

Cell Circuit: Supplies electrical energy from larger terminal (+) positive sign.
Battery Circuit: A Battery is two or more cells, the function of battery circuit is the same as cell circuit.
DC Circuit Symbol: Direct current (DC) always flows in one direction.
AC Circuit Symbol: AC (Alternating Current) flows periodically reverses direction.
Fuse Circuit: The fuse will flow sufficient current and it is used to provide overcurrent protection.
Transformer: It is used to produce AC power supply, energy is transferred in between primary and secondary coils in the form of mutual inductance.
Solar cell: It will convert light energy into electrical energy.
Earth: It supplies the 0V to the circuit that will connect to the earth.
Voltage Source: It will supply voltage to the circuit elements.
Current Source: It will supply current to the circuit elements.
AC Voltage Source: It will supply the AC voltage to the circuit elements.
Controlled Voltage Source: It generates controlled voltage to the circuit elements.
Controlled Current Source: It generates controlled current to the circuit elements.

Resistors

A Resistor is a passive element that opposes current flow in a circuit. It is a two-terminal element, dissipates its energy in the form of heat. The resistor will damage due to the overflow of electric current through it. Resistance is measured in units of ohms and resistance, resistor color code calculator is used to calculate the value of the resistor according to its colors.

Resistor: It is a two terminal component, that restricts the flow of current.
Rheostat: It is a two terminal component, that is used to adjust the flow of current.
Potentiometer: Potentiometer is a three-terminal component that will adjust the voltage flow in the circuit.
Preset: Preset is a low-cost adjustable resistor that operates by using small tools like Screwdrivers.

Capacitors

A Capacitor generally referred to as a condenser, it is a two-terminal passive component that will capable of storing energy in the form of electricity. These are the rechargeable batteries mainly used in power supply. In the capacitors, electrical plates differ by a dielectric medium and these are acts like a filter that allows only AC signals and blocks DC Signals. The capacitors are classified into various types that are discussed below

Capacitor: A capacitor is used to store the energy in electrical form.
Polarized Capacitor: Stores electrical energy these must be a one way round.
Variable Capacitor: These capacitors are used to control the capacitance by adjusting the Knob.
Trimmer Capacitor: These capacitors are used to control the capacitance by using Screwdriver or similar tools.

Diodes

A Diode is an electronic component with two terminals that are anode and cathode. It allows electron current flow from cathode to anode but it blocks another direction. The diode will have low resistance in one direction and high resistance in another direction. The diodes are classified into various types that are discussed below

Diode: A diode allows the current flow in one direction.
Light Emitting Diode: It will emit the light when the electric current flows through it.
Zener Diode: It will allow a constant electric current after the breakdown voltage.
Photo Diode: Photodiode will convert light into respective current or voltage.
Tunnel Diode: Tunnel diode is used for very high-speed operations.
Schottky Diode: Schottky diode is for forwarding low voltage drop.

Transistors

The transistors are invented in 1947 at Bell Laboratories to replace vacuum tubes, that it will control the flow of current and voltage in the circuits. It is a three terminal device and amplifies the current, transistors plays an important role in all modern electronics.

NPN transistor: A P-type doped semiconductor material is placed in between two N-type semiconductor materials. The terminals are the emitter, base, and collector.
PNP transistor: A N-type doped semiconductor material is placed in between two P-type semiconductor materials. The terminals are an emitter, base, and collector.
Phototransistor: It is similar to bipolar transistors, but it converts light to current.
Field Effect Transistor: FET controls the conductivity with the help of an electric field.
N-channel JFET: The Junction Field Effect Transistors are simple of FET for switching.
P-channel JFET: P-type semiconductor is placed in between N-type junctions.
Enhancement MOSFET: Similar to DMOSFET but an absence of conducting channel.
Depletion MOSFET: The current flows from source to drain terminal.

Meters

A Meter is an instrument used for measuring voltage and current flow in electrical and electronic components. These are used to measure the resistance and capacitance of the electronic components.

Voltmeter: It is used to measure voltage.
Ammeter: It is used to measure current.
Galvanometer: It is used to measure small currents.
Ohmmeter: It is used to measure the electrical resistance of a particular resistor.
Oscilloscope: It is used to measure voltage with respect to time for signals.

Switches

A Switch is an electrical/electronic component that will connect electrical circuits when the switch is closed, otherwise, it will break an electrical circuit when the switch is open.

Push switch: It will pass the current flow when the switch is pressed.
Push to break switch: It will block the current flow when the switch is pressed.
Single pole single throw switch (SPST): Simply, it is an ON/OFF switch allows flow only when the switch is in ON.
Single pole double throw switch (SPDT): In this type of switch current flows in two directions.
Double pole single throw switch (DPST): It is a dual SPST switch, mainly used for electrical lines.
Double pole double throw switch (DPDT): It is a dual SPDT switch.
Relay: A relay is a simple electromechanical switch made up of an electromagnet & a set of contacts. These are found hidden in all sorts of devices.

Audio Devices

These devices convert an electric signal into sound signals and vice versa, which will be audible to humans. These are input/output electronic components in the circuit diagram.

Microphone: converts sound or noise signal to an electrical signal.
Earphone: converts an electrical signal to a sound signal.
Loudspeaker: converts the electrical signal to sound signal but it will amplify version.
Piezo- transducer: converts flow of electrical energy to sound signal.
Bell converts the electrical signal to sound signal.
Buzzer: converts an electrical signal to sound signal.

Sensors

Sensors will sense or detect moving objects and devices, it will convert those signals into electrical or optical. For example, a temperature sensor is used sense temperature present in the room. The various types of sensors are

Light-dependent resistor: These sensors will sense light.
Thermistor: These sensors will sense heat or temperature.

Logic Gates

Logic gates are the main building blocks in the digital circuits, logic gates will have two or three inputs and a single output. The output produced by logic gates based on certain logic. Basic Logic gate values represent in binary if we observe their truth tables.

AND Gate: The output value is HIGH when two inputs are HIGH.
OR Gate: The output value is HIGH when one of the inputs is HIGH.
NOT Gate: The output is the complement of the input.
NAND Gate: The complement of the AND gate is a NAND gate.
NOR Gate: The complement of the OR gate is a NAND gate.
X-OR Gate: The output is HIGH when an odd number of HIGH occurs in its inputs.
X-NOR Gate: The output is HIGH when an even number of HIGH occurs in its inputs.

Other Components

These are the some of the electronic/electrical components that are utilized in an electronic circuit or electrical circuit design.

Lighting Lamp: It is a bulb that will glow when certain current flows.
Indicator Lamp: It will convert electricity to light.
Inductor: It will generate a magnetic field when current flows through it.
Antenna: It is used to transmit and Receive the radio signals.

Thus, this is all about electronic circuit symbols. Hope this article gives you a brief information by reading the above article. Furthermore, any queries regarding this article or electronics projects, please share your valuable suggestions by commenting in the comment section below. Here is a question for you, what are active and passive components?

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Different Types of Electronic Circuit with Symbols

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Electronics is a branch of an engineering, which deals with electronic and electrical circuits like Integrated circuits, Transmitters, and Receiver etc. The electronic circuit is defined as it is a combination of various electronic components that allow the flow of electric current.

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The problems of translate on the Qazaq language

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The problems of translate on the Qazaq language

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the problems ol Google translate by Qazaq

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electronic-components

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ElProCus - Electronic Projects for Engineering Students

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There are numerous basic electronic components that are used for building electronic circuits. Without these components, circuit designs are never complete or didn't function well. These components include resistors, diodes, capacitors, integrated circuits, and so on. Some of these components consists of two or more terminals which are soldered to circuit boards. Some may be packaged type like integrated circuits in which different semiconductor devices are integrated. Here is a brief overview on each of these basic electronic components and you can get in depth information by clicking links attached to each component.

Basic Electronics Components

An electronic circuit comprises of various types of components, which are classified into two types: active components like transistors, diodes, IC's; and passive components like capacitors, resistors, inductors, etc.

In designing of an electronic circuit following are taken into consideration:

Basic electronic components: capacitors, resistors, diodes, transistors, etc.

Power sources: Signal generators and DC power supplies.

Measurement and analysis instruments: Cathode Ray Oscilloscope (CRO), multimeters, etc.

Passive Electronic Components

These components can store or maintains energy either in the form of current or voltage. Some of these components are discussed below.

Resistors

A resistor is a two-terminal passive electronics component, used to oppose or limit the current. Resistor works based on the principle of Ohm's law which states that "voltage applied across the terminals of a resistor is directly proportional to the current flowing through it"
V=IR

The units of the resistance is ohms
Where R is the constant called resistance

Resistors are further classified based on the following specifications such as the power rating, type of material used and resistance value. This resistor types are used for different applications.

Fixed resistors:

This type of resistor is used to set the right conditions in an electronic circuit. The values of resistance in fixed resistors are determined during the design phase of the circuit, based on this there is no need to adjust the circuit.

Variable resistors:

A device that is used to change the resistance according to our requirements in an electronic circuit is known as a variable resistor. These resistors comprise of a fixed resistor element and a slider which taps on to the resistor element. Variable resistors are commonly used as a three terminal device for calibration of the device.
Know more about resistors
Capacitors:

A capacitor made from two conductive plates with an insulator between them and it stores electrical energy in the form of an electric field. A capacitor blocks the DC signals and allows the AC signals and also used with a resistor in a timing circuit.
The stored charge is Q=CV

Where
C is the capacitance of a capacitor and
V is the applied voltage.

These capacitors are different types like film, ceramic, electrolytic and variable capacitors. For finding its value number and color coding methods are used and it also possible to find the capacitance value with LCR meters.
Know more about capacitors
Inductors

An inductor is also referred as AC resistor which stores electrical energy in the form of magnetic energy. It resists the changes in the current and the standard unit of inductance is Henry. Capability of producing magnetic lines is referred as inductance.

The inductance of the inductor is given as L= (µ.K.N2.S)/I.

Where,

L is inductance,
µ is Magnetic permeability,
K is magnetic coefficient,
S is theCross section area of the coil,
N is the Number of turns of the coils,
And I is the Length of the coil in axial direction.

Other passive electronic components include different types of sensors, motors, antennas, memristors, etc. To reducing the complexity of this article few of the passive components are discussed above.
Know more about inductors
Active Electronic Components

These components rely on a source of energy and are able to control the electron flow through them. Some of these components are semiconductors like diodes, transistors, integrated circuits, various displays like LCD, LED, CRTs and power sources like batteries, PV cells and other AC and DC supply sources.

Diodes

A diode is a device that allows current to flow in one direction and usually made with semiconductor material. It has two terminals, anode and cathode terminals. These are mostly used in converting circuits like AC to DC circuits. These are are of different types like PN diodes, Zener diodes, LEDs, photo diodes, etc.
Know more about diodes
Transistors

A transistor is a three terminal semiconductor device. Mostly it is used as switching device and also as an amplifier. This switching device can be a voltage or current controlled.By controlling the voltage applied to the one terminal controls the current flow through the other two terminals. Transistors are of two types, namely bipolar junction transistor (BJT) and field effect transistors (FET). And further these can be PNP and NPN transistors.
Know more about transistors
Integrated Circuits

An Integrated circuit is a special component which is fabricated with thousands of transistors, resistors, diodes and other electronic components on a tiny silicon chip. These are the building blocks of current electronic devices like cell phones, computers, etc. These can be analog or digital integrated circuits. Mostly used ICs in electronic circuits are Op-amps, timers, comparators, switches ICs and so on. These can be classified as linear and nonlinear ICs depending on its application.
Know more about ICs
Display Devices

LCD: A liquid crystal display (LCD) is a flat display technology, which is mostly used in applications like computer monitors, cell phone display, calculators, etc. This technology uses two polarized filters and electrodes for selectively disable or enable the light to pass from reflective backing to the eyes of the viewer.
Know more about LCD CRT:
Cathode ray tube display technology is mostly used in televisions and computer screens that works on the movement of an electron beam back and forth on the back of the screen. This tube is an elongated vacuum tube in which flattened surface has external components as electron gun, electron beam and a phosphorescent screen.
Know more about CRT
Batteries

Batteries are most common power source for standalone industrial, domestic and handheld device applications. It converts chemical energy into electrical energy through electrochemical discharge reactions. These consist of one or more cells and each cell contains an anode, cathode and the electrolyte. The battery cells are classified into two types namely primary cells and secondary cells. The primary cells are not of rechargeable type but the secondary cells cab be rechargeable.
Know more about Batteries
These are the few basic electronic components with a brief explanation on attached links. Along with electronic components symbols, reader might have got a basic idea about these components. We are pioneers in developing electronics projects using these basic components with advanced controllers.Therefore, readers can comment below regarding any help for testing these components and practical assembling into electronic circuits.

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Overview of Various Basic Electronic Components

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There are numerous basic electronic components that are used for building electronic circuits. Without these components, circuit designs are never complete or didn't function well. These components include resistors, diodes, capacitors, integrated circuits, and so on. Some of these components consists of two or more terminals which are soldered to circuit boards.

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online test

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Total questions: 15 | Time: 15 minutes | No negative marks

Electronics test 2 (Atoms 2)

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Total questions: 15 | Time: 15 minutes | No negative marks Electronics test 2 (Atoms 2) Total questions: 15 | Time: 15 minutes | No negative marks Electronics test 3 (Semiconductors 1) Total questions: 15 | Time: 15 minutes | No negative marks Electronics test 4 (Semiconductors 2) Total questions:

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the lecture

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Field Effect Transistors - an overview | ScienceDirect Topics

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Field effect transistors (FETs) are electrochemical transducers upon which micro-sized solid-state chemical sensors and biosensors, the so-called Bio-chem-FETs, can be developed. The chapter first discusses the key issues of FET operation. It then describes the ways of introducing chemical and biochemical sensitivity and selectivity to analytes, using either chemically activ sensing elements or biological recognition elements.

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Advertisement

by Chris Woodford. Last updated: May 29, 2021.

Transistors are the tiny electronic components that changed the world: you'll find them in everything from calculators and computers to telephones, radios, and hearing aids. They're amazingly versatile, but that doesn't mean they can do everything. Although we can use them to switch tiny electrical currents on and off (that's the basic principle behind computer memory), and transform small currents into somewhat larger ones (that's how an amplifier works), they're not very useful when it comes to handling much bigger currents. Another drawback is that they turn off altogether as soon as the switching current is removed, which means they're not so useful in devices such as alarms where you want a circuit to trigger and stay on indefinitely. For those sorts of jobs, we can turn to a somewhat similar electronic component called a thyristor, which has things in common with diodes, resistors, and transistors. Thryristors are reasonably easy to understand, though most of the explanations you'll find online are unnecessarily complex and often confusing beyond belief. So that's our starting point: let's see if we can take a clear and simple look at what thyristors are, how they work, and what kinds of things we can use them for!

Artwork: A typical thyristor looks a bit like a transistor-and works in a closely related way.

What are thyristors?

First, let's nail some terminology. Some people use the term silicon-controlled rectifier (SCR) interchangeably with "thyristor." In fact, silicon-controlled rectifier is a brand name that General Electric introduced to describe one particular kind of thyristor that it made. There are various other kinds of thyristors too (including ones called diacs and triacs, which are designed to work with alternating current), so the terms aren't completely synonymous. Nevertheless, this article is about keeping things simple, so we'll just talk about thyristors in the most general terms and assume SCRs are exactly the same thing. We'll refer to them as thyristors throughout.

Photo: Thyristors are widely used in electronic power control circuits like this one.

Three connections

So what is a thyristor? It's an electronic component with three leads called the anode (positive terminal), cathode (negative terminal), and gate. These are somewhat analogous to the three leads on a transistor, which you'll remember are called the emitter, collector, and base (for a conventional transistor) or the source, drain, and gate (in a field-effect transistor, or FET). In a conventional transistor, one of the three leads (the base) acts as a control that regulates how much current flows between the other two leads. The same is true of a thyristor: the gate controls the current that flows between the anode and the cathode. (It's worth noting that you can get thryistors with two or four leads, as well as three-lead ones. But we're keeping things simple here, so we'll just talk about the most common variety.)

Transistors versus thyristors

If a transistor and a thyristor do the same job, what's the difference between them? With a transistor, when a small current flows into the base, it makes a larger current flow between the emitter and the collector. In other words, it acts as both a switch and an amplifier at the same time:

How a transistor works: A small current flowing into the base makes a larger current flow between the emitter and the collector. This is an n-p-n transistor with red indicating n-type silicon, blue indicating p-type, black dots representing electrons and white dots representing holes.

A similar thing happens inside a FET, except that we apply a small voltage to the gate to produce an electric field that helps a current flow from the source to the drain. If we remove the small current at the base (or gate), the large current immediately stops flowing from the emitter to the collector (or from the source to the drain in a FET).

Now often that's not what we want to happen. In something like an intruder alarm circuit (where maybe an intruder steps on a pressure pad and the bells start ringing), we want the small current (activated by the pressure pad) to trip the larger current (the ringing bells) and for the larger current to keep on flowing even when the smaller current stops (so the bells still ring even if our hapless intruder realizes his mistake and steps back off the pad). In a thyristor, that's exactly what happens. A small current at the gate triggers a much larger current between the anode and the cathode. But even if we then remove the gate current, the larger current keeps on flowing from the anode to the cathode. In other words, the thyristor stays ("latches") on and remains in that state until the circuit is reset.

Where a transistor generally deals with tiny electronic currents (milliamps), a thyristor can handle real (electric) power currents (several hundred volts and 5-10 amps is typical). That's why we can use them in such things as factory power switches, speed controls for electric motors, household dimmer switches, car ignition switches, surge protectors, and thermostats. Switching time is practically instantaneous (measured in microseconds), and that useful feature, coupled with a lack of moving parts and high reliability, is why thyristors are often used as electronic (solid-state) versions of relays (electromagnetic switches).

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How does a thyristor work?

Thyristors are a logical extension of diodes and transistors, so let's briefly recap on those components. If you're unfamiliar with solid-state electronics, we have longer and clearer explanations of how diodes work and and how transistors work, which you might like to read first.

A thyristor is like two diodes

Recall that a diode is two layers of semiconductor (p-type and n-type) sandwiched together to produce a junction where interesting things happen. According to how you wire up a diode, current will either flow through it or not, making it the electronic equivalent of a one-way street. With a positive connection to the p-type (blue) and a negative connection to the n-type (red), a diode is forward biased, so electrons (black dots) and holes (white dots) move happily across the junction and a normal current flows:

A forward-biased diode: current flows across the junction between the p-type (blue) and n-type (red), carried by electrons (black dots) and holes (white dots).

In the opposite configuration, with a positive connection to the n-type and a negative to the p-type, a diode is reverse biased: the junction becomes a huge chasm that electrons and holes can't cross and no current flows:

A reverse-biased diode: with the battery connected the other way, the "depletion zone" at the junction gets wider, so no current flows.

In a transistor, we have three layers of semiconductor arranged alternately (either p-n-p or n-p-n), giving two junctions where interesting things can happen. (A FET is slightly different, with extra layers of metal and oxide, but still essentially an n-p-n or p-n-p sandwich.). A thyristor is simply the next step in the sequence: four layers of semiconductor, again arranged alternately to give us p-n-p-n (or n-p-n-p if you swap it around) with three junctions in between them. The anode connects to the outer p layer, the cathode to the outer n layer, and the gate to the internal p layer, like this:

A thyristor is like two junction diodes connected together, but with an extra connection to one of the inner layers-the "gate."

You can see that this resembles two junction diodes connected in series, but with the extra gate connection at the bottom. Just like a diode, a thyristor is a rectifier: it conducts in only one direction. You can't make a thyristor simply by wiring two diodes in series: the extra gate connection means there's more to it than that. If you're quite familiar with electronics, you'll note the resemblance between a thyristor and a Shockley diode (a kind of double diode with four alternating semiconductor layers, invented by Transistor pioneer William Shockley in 1956). Thyristors evolved from Shockley's transistor and diode work, which was further developed by Jewell James Ebers, who developed the two-transistor model we're going to cover next.

Artwork: General Electric introduced the first commercially successful thyristor (then called a silicon-controlled rectifier) in July 1957, thanks to the efforts of Robert Hall, Nick Holonyak, F. W. "Bill" Gutzwiller, and others. This is a basic illustration of a thyristor from one of Bill Gutzwiller's patents. Artwork from US Patent 3,040,270: Silicon controlled rectifier circuit including a variable frequency oscillator courtesy of US Patent and Trademark Office.

A thyristor is like two transistors

What's less obvious is that the four layers work like two transistors (an n-p-n and a p-n-p) that are connected together so the output from one forms the input to the other. The gate serves as a kind of "starter motor" to activate them.

A thyristor is also like two transistors connected together, so the output from each one serves as the input to the other one.

The three states of a thyristor

So how does this thing work? We can put it into three possible states, in all three of which it's either completely off or completely on, which means it's essentially a binary, digital device. To understand how these states work, it helps to keep diodes and transistors in mind:

Forward blocking

Normally, with no current flowing into the gate, a thyristor is switched off: no current can flow from the anode to the cathode. Why? Think of the thyristor as two diodes joined together. The upper diode and the lower diode are both forward biased. However, that means the junction in the center is reverse biased, so there's no way for current to get all the way from the top to the bottom. This state is called forward blocking. Although it's similar to forward-bias in a conventional diode, no current flows.

Reverse blocking

Suppose we reverse the anode/cathode connections. Now you can probably see that both the upper and lower diodes are reverse biased, so still no current flows through the thyristor. This is called reverse blocking (and it's analogous to reverse bias in a simple diode).

Forward conducting

The third state is the really interesting one. We need the anode to be positive and the cathode negative. Then, when a current flows into the gate, it switches on the lower transistor, which switches on the upper one, which switches on the lower one, and so on. Each transistor activates the other. We can think of this as a kind of internal, positive feedback in which the two transistors keep feeding current to each other until both of them are fully activated, at which point current can flow through them both from the anode to the cathode. This state is called forward conducting and it's how a thyristor "latches" (stays permanently) on. Once a thyristor is latched on like this, you can't turn it off simply by removing the current to the gate: at this point, the gate current is irrelevant-and you have to interrupt the main current flowing through from the anode to the cathode, often by switching off power to the entire circuit. Don't follow that? Check out the animation in the box below, which I hope will make it clear.

How a thyristor latches on

This little animation is a simple summary of how a thyristor latches on. You'll notice I've redrawn the thyristor so it looks like two transistors (a p-n-p at the top and an n-p-n beneath it) connected together, with the anode, cathode, and gate making the three external connections. Each transistor acts as the input to the other. So how does it work?

1. With no current flowing into the gate, the thyristor is switched off and no current flows between the anode and the cathode.

2. When a current flows into the gate, it effectively flows into the base (input) of the lower (n-p-n) transistor, turning it on.

3. Once the lower transistor is switched on, current can flow through it, activating the base (input) of the upper (p-n-p) transistor, turning that on as well.

4. Once both transistors are turned on completely ("saturated"), current can flow all the way through both of them-through the entire thyristor from the anode to the cathode.

5. Since the two transistors keep one another switched on, the thyristor stays on-"latches"-even if the gate current is removed.

Types of thyristors

Somewhat simplified, that's the crux of how a thyristor works. There are numerous variations, including gate-turn off (GTO) devices (that can be turned on or off by the action of the gate), AGT (anode gate thyristor) devices that have a gate going to the internal n-type layer near the anode (instead of the p-type layer near the cathode), photoelectric thyristors in which the base is activated by light, and all kinds of others. But they all work in broadly similar ways, with a gate tripping one transistor, which then trips the other.

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On this website

You might like these other articles on our site covering similar topics:

Books

Thyristor books

Don't worry that these books are "old": broadly speaking, the physics of semiconductors never dates.

Thyristor Device Data: Motorola, 1988. A detailed compendium of data sheets and more.

Thyristor Physics by Adolph Blicher, Springer, 1976. A detailed look at the solid-state physics of thyristors. You can read the whole text online if you "borrow" the book virtually from the Internet Archive.

110 Thyristor Projects by R.M. Marston, Newnes, 1972. A huge collection of practical thyristor circuits, including power-switching projects, alarms, time-delay circuits, lamp controllers, heater controllers, and motor controllers.

Power Electronics Handbook: Devices, Circuits, and Applications by Muhammad Rashid (ed). Elsevier 2018. Chapters 7-9 cover thyristors.

Semiconductor Controlled Rectifiers: Principles and Applications by F.E. Gentry, F.W. Gutzwiller, and Nick Holonyak, Prentice Hall, 1964. An old but definitive account by the inventors of the technology.

General textbooks

Articles

General

Cosmic Ray Failures of Power Semiconductor Devices: IEEE Spectrum, June 21, 2019. How particles from space can cause failures in power semiconductor devices, such as thyristors.

Try a Triac by Charles Platt. Make, January 10, 2014. Learn about triacs with this hands-on LED project.

High-Power Electronics by Narain G. Hingorani and Karl E. Stahlkopf, Scientific American, Vol 269 No 5, November 1993. An easy-to-understand overview of how high-voltage components such as thyristors are used in power control and transmission.

History

How B. Jayant Baliga Transformed Power Semiconductors by David Schneider. IEEE Spectrum, April 27, 2014. Celebrating the work of B. Jayant Baliga, winner of the 2014 IEEE Medal of Honor, developing thyristors and other power semiconductors.

The silicon p-n-p-n switch and controlled rectifier (thyristor) by Nick Holonyak, Jr. IEEE Transactions on Power Electronics, Jan 2001, Volume 16 Issue 1, pp8-16. This interesting paper (by the inventor of the LED) describes the historical development of thyristors by William Shockley, Jim Ebers, and others.

Early power semiconductor history at GE: The Semiconductor Museum presents an early history of the silicon controlled rectifier, as told in an oral history by one of its pioneers, F.W. "Bill" Gutzwiller.

Patents

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How do thyristors work? | Thyristors and transistors compared

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Advertisement by Chris Woodford. Last updated: May 29, 2021. Transistors are the tiny electronic components that changed the world: you'll find them in everything from calculators and computers to telephones, radios, and hearing aids. They're amazingly versatile, but that doesn't mean they can do everything.

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Op-amp Tutorial Includes:
Introduction Op amp gain Bandwidth Op amp slew rate Offset null Input impedance Output impedance Understanding specifications How to choose an op amp Op amp circuits summary

Integrated circuits, ICs have made a huge impact on the electronics scene - both analogue and digital circuits have changed the face of electronics.

Within the analogue electronics arena, none has made more difference than the operational amplifier, or op-amp. The op-amp enables a very high performance amplifier to be made with the addition of just a handful of other components.

The operational amplifier can also form the basis of a host of other circuits ranging from filters to timers, and oscillators to comparators and astables. As such the operational amplifier is one of the most versatile building blocks available to the analogue engineer and hobbyist.

Operational amplifier basics are relatively straightforward and circuit design for many circuits is easy.

Operational amplifier circuit symbol with ICs

Op-amp development

Although the term operational amplifier has now become totally integrated into today's electronics terminology, it may not be realised that it dates back to a paper published in 1947. This described work that was undertaken using these amplifiers in analogue computers of the day.

However it was not until the 1960s that the concept of these amplifiers could be fully realised with the widespread introduction of integrated circuit technology. With the improvement in integrated circuit technologies in the 1970s, the use of op-amps increased further and the rest as they say is history!

Now operational amplifiers have become a fundamental building block used throughout the electronics industry. Even though they have been around for some time, there seems to be little likelihood of their use falling.

What is an Op-Amp? The Basics

An operational amplifier is a very close approximation to a perfect amplifier with an infinite gain. In reality op-amps do not quite attain perfection, but with gains often in the region of 100 000 or more, they are sufficiently close.

The operational amplifier has two inputs. One is called the inverting input and is marked with a "-" sign on circuit schematic diagrams. The other is the non-inverting input and this is marked with a "+" sign.

Operational amplifier circuit symbol

The two inputs gain their names from the way in which they amplify the signals:

Non-inverting input: The operational amplifier non-inverting input is marked by a "+" sign on the circuit diagram. It is found that a positive voltage applied to the non-inverting input will produce a positive swing at the output.

Inverting input: &nbsp The operational amplifier inverting input is marked by a "-" sign on the circuit diagram. A positive voltage applied to the inverting input will produce a negative swing at the output.

If the same voltage is applied to both inputs together then there should be no change at the output. In fact the output is proportional to the difference between the inverting and non-inverting inputs. It is for this reason that these amplifiers are often called differential amplifiers.

Like any electronics circuit, those using operational amplifiers need to have a power supply. Normally op-amps are supplied using dual, i.e. positive and negative supplies. Additionally the supply lines are often not shown as they add confusion to the circuit diagram.

In most cases the operational amplifier will only need five connections for its operation - inverting, non-inverting, output and the two power rails. Very occasionally a further three may be used. These are usually for the "offset null" capability. This is used to reduce any DC offsets that may be present, and for most applications these can be ignored and left disconnected.

Operational amplifier characteristics

Operational amplifiers, op-amps have a number of basic features some of which provide advantages, others limit their performance:

Operational amplifier characteristics

Very high gain: One of the key attributes of operational amplifiers is their very high gain. Typical figures extend from around 10 000 upwards - figures of 100 000 and more are common. Although an open loop amplifier with a level of gain of this order would be of little use, op-amps are able to harness the advantages of the very high gain levels by using negative feedback. In this way the gain levels are very controllable and distortion levels can be kept very low.

High input impedance: A high input impedance is another key aspect of op-amps. In theory their input resistance should be infinite, and the op-amps in use today come very close to this with impedances anywhere from 0.25MΩ upwards. Some using MOSFET input stages have an impedance of hundreds of MΩ.

Low output impedance: The op-amp output impedance is also important. As may be expected this should be low. In the ideal amplifier this should be zero, but in reality many amplifiers have an output impedance of less than a hundred ohms, and many very much less than this. That said, the drive capability of many IC based op-amps is naturally limited.

Common mode rejection: Another important feature of the op-amp is its common mode rejection. This refers to the situation where the same signal is applied to both inputs. In an ideal amplifier no output should be seen at the output under these circumstances, however the amplifier will never be perfect. The actual common mode rejection ratio is the ratio between the output level when the signal is applied to both inputs compared to the output when it is applied to just one

Limited bandwidth: The bandwidth of an op-amp can vary quite widely. An ideal amplifier would have an infinite bandwidth but as one may imagine this would be impossible create, and also very difficult to use and tame in practise. In reality op-amps have a limited bandwidth. Many of the chips used for audio applications may only exhibit their full gain over a relatively small bandwidth, after this the gain falls. Despite this most circuits act to reduce the gain, and enable this smaller level of gain to be maintained over a larger bandwidth.

Basic op-amp circuits

Although operational amplifiers are widely used as amplifiers, they can also be as the basis of many other circuits.

As op amp circuits place feedback around the amplifier, changing this changes the properties of the overall circuit. Not only can changing he feedback alter the level of gain, but it can change the function of the circuit - it is possible to make differentiators, integrators, filters, oscillators, astable, multivibrators, and many more circuits simply by changing the feedback levels and configuration.

There are many different circuits based around op amps. These are generally easy to design and construct.

The operational amplifier is a very useful building block for analogue electronics. In view of the widespread use, chips are very cheap and can be used for a wide variety of functions.

More Circuits & Circuit Design:
Op Amp basics Op Amp circuits Power supply circuits Transistor design Transistor Darlington Transistor circuits FET circuits Circuit symbols
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Op Amp Basics | What is an Operational Amplifier | Electronics Notes

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Op-amp Tutorial Includes: Introduction Op amp gain Bandwidth Op amp slew rate Offset null Input impedance Output impedance Understanding specifications How to choose an op amp Op amp circuits summary Integrated circuits, ICs have made a huge impact on the electronics scene - both analogue and digital circuits have changed the face of electronics.

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What is a Thyristor? - A Galco TV Tech Tip - YouTube

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What is a Thyristor? - A Galco TV Tech Tip - YouTube

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What is a Thyristor? - A Galco TV Tech Tip

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Resistor Color Code Calculator and Chart (4-band, 5-band or 6-band)

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Resistor Color Code Calculator and Chart (4-band, 5-band or 6-band)

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Resistor Color Code Calculator and Chart—4 Band, 5 Band, or 6 Band Resistors - Engineering Calculators & Tools

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A handy all-in-one tool for reading resistor color code values for a 4 band resistor, 5 band resistor, or 6 band resistor.

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203 aud.

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Основы электронной и измерительной техники

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National Instruments

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How to build a Schmitt trigger using transistors?

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How to build a Schmitt trigger using transistors?

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The schmitt trigger part (Q1 and Q3) actually works. What doesn't work is your output stage. Check the possible voltages at Q3 collector:

When Q3 is off, it is obviously close to the supply voltage. Therefore, there will be current through R3 and Q4 will conduct.

When Q3 conducts, the current through RC2 will go through RE and, although it will be a bit closer to ground, the voltage across RE still makes it much closer to the supply than ground. Q4 actually still conducts. The current path is: RC2 -> (R3 || RE).

To quickly fix this, you can use a PNP at the output, instead of a NPN. You'll also have to increase RC2 because with 1k, you're still too close to the supply voltage (which then changes the thresholds, yes, but anyway...). Also, you can remove R3 since RE is already here to limit current through Q4 base.

Here is the new schematic:
simulate this circuit - Schematic created using CircuitLab
With this new circuit, simulation show the thresholds are 3V and 4.5V (I'm way too lazy to confirm this by formulas). Here is the LTspice (which I find waaaay more productive than circuitlabs) asc file pastebin.

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How to build a Schmitt trigger using transistors?

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The schmitt trigger part (Q1 and Q3) actually works. What doesn't work is your output stage. Check the possible voltages at Q3 collector: When Q3 is off, it is obviously close to the supply voltage. Therefore, there will be current through R3 and Q4 will conduct.

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How does a Schmitt trigger circuit work?

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How does a Schmitt trigger circuit work?

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How does a Schmitt trigger circuit work?

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Answer (1 of 7): A Schmitt trigger is a circuit which generates an output waveform of a square wave of a particular duty cycle. It can be implemented on several devices, however most commonly on the operational amplifier. When we give a positive feedback to the opamp, it no more behaves as a lin...

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Answer the following . . . JavaScript is required! This is a simple test to see how much you know about basic electronics.

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http://onmyphd.com/?p=analog.digital.converter

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Analog-Digital Converters (ADC) - A Tutorial with types of converters, their circuits and interactive examples

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Analog-Digital converters convert analog signals such as sound and image into a digital representation. There are various types of ADCs, each one with its strengths and weaknesses. Here are show their block diagrams and/or circuits, with interactive examples.