Beginners guide to electronic circuits and circuit design
Simple electronic switch circuit
To get started with the basics of electronics we are going to look at a very basic circuit with a switch that can turn a light on and off. Okay this may not be exactly what you are hoping to achieve in terms of creating the latest computer controlled electronic gadget, but that will come a bit later. For the moment we need to look at the basics and learn to walk before we can run.
Lets first look at some basics about electricity and how it works. I've kept this to the very minimum so that we can get on to creating our first circuit.
Electricity, electric current and electrons
We all know of electricity as the energy that makes our lights shine, powers the TV and for which the energy companies like to charge us lots of money for using, but to understand electronics we need to look at what electricity is. Essentially electricity is caused by subatomic particles called electrons which move around the electronic circuit interacting with the various components. The electrons always flow in a full circuit needing to get back to where they started (ie the battery), althoug as we will see to different terminals of that battery. This also sounds kind of complicated, but from the point of view of designing electronic circuits (rather than designing the components themselves) you don't need to go any deeper, but I will be referring to electrons again in future. With that out of the way we can now look at how we control these electrons.
Conductors vs. insulators
Electrons (ie. electricity) can move through some materials much more easily than others. The wires connecting the mains electricity to a mains appliance is normally made of copper as this allows the electrons to pass very easily, but to save you getting electrocuted every time you touch the power lead the copper wire is covered in a plastic coating which does not allow the electrons to pass through.
Materials that allow the electrons to move easily are called conductors, whereas those that prevent electrons from flowing are called insulators. It is these properties that allow us to control where electricity is allowed to pass and to be able to turn devices on and off. The insulating properties of a material will differ depending upon the material and the thickness, so an appropriate insulator should always be used when dealing with electricity especially with mains electricity .
Some common conductors and insulators are listed in the following table:
Conductor
Insulator
Copper wire
Most plastics
Other metals
Dry wood
Tap / rain water*
Glass and ceramics
People!
Air
Note that I specifically mention tap and rain water rather than just water. Pure distilled water is actually an insulator, but the impurities in most water turns it into a conductor. Never operate live mains equipment near water or outside in the rain, unless the equipment is specifically designed for that purpose .
There is another type of material called a semi-conductor whose properties can change between an insulator and a conductor under certain conditions, but we'll look more at semiconductors later when we get on to active components.
Complete circuit
This is an example of a real circuit used in battery operated torches.
For any electronic circuit to work there must be a complete circuit. This means that there must be a connection made out of conducting material that goes in a circle from one terminal of the battery through the equipment and then back to the other terminal of the battery. If there is a gap at any point then we have air which is a bad conductor and as a result nothing will happen.
This is how a switch works.
When the switch is in the open position then it creates a break in the circuit and the light is off. When the switch is closed the metal contacts inside the switch join and complete the circuit.
Press the switch button using your mouse to see the lamp light up..
The circuit diagram (schematic)
The picture that you can see is known as a circuit diagram or a schematic diagram. This is the standard way of showing an electronic circuit so that you can see how the circuit should work. Each component has its own symbol which indicates what it's function is. There are a number of different electronic component circuit symbols in the electronics reference section. The symbol on the left is for a battery, at the top there is the symbol for a switch and at the right the circle with a cross in it is the symbol for an lamp (or indicator lamp).
Note that when a circuit is created there is often a component layout diagram which shows how the components are installed onto the circuit board. This is useful if you are creating a replica of a circuit that has already been designed, but it is the schematic (circuit diagram) that is most useful for understanding how and why a circuit works as it does.
Unfortunately circuit diagrams / schematics do not always look exactly the same as there are differences in the circuit symbols used depending upon region and preference. For example the resistor in the IEC circuit symbols is shown as a rectangle, but in the US a resistor is normally shown as a zig-zag line. In most cases the differences are only small and it's still possible to recognise the symbol even if it is not the one you are familiar with, but in the worst case it usually means there are a couple of extra symbols to remember / look-up.
The picture representation of the switch is not part of the circuit diagram but is provided as a means to interact with the circuit. Also circuit diagrams are normally static and the switch symbol would not normally change to the closed position, or the lamp change colour .
XXX . V Electronic component
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 are mostly industrial products, available in a singular form and are not to be confused with electrical elements, which are conceptual abstractions representing idealized electronic components.
Electronic components have a number of electrical terminals or leads. These leads connect 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 semiconductorintegrated circuits, hybrid integrated circuits, or thick film devices. The following list of electronic components focuses on the discrete version of these components, treating such packages as components in their owner right.
Various electronic components.
Components can be classified as passive, active, or electromechanic. 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.
However, electronic engineers who perform circuit analysis use a more restrictive definition of passivity. When only concerned with the energy of signals, it is convenient to ignore the so-called DC circuit and pretend that the power supplying components such as transistors or integrated circuits is absent (as if each such component had its own battery built in), though it may in reality be supplied by the DC circuit. Then, the analysis only concerns the AC circuit, an abstraction that ignores DC voltages and currents (and the power associated with them) present in the real-life circuit. This fiction, for instance, lets us view an oscillator as "producing energy" even though in reality the oscillator consumes even more energy from a DC power supply, which we have chosen to ignore. Under that restriction, we define the terms as used in circuit analysis as:
Active components rely on a source of energy (usually from the DC circuit, which we have chosen to ignore) and usually can inject power into a circuit, though this is not part of the definition.[1] Active components include amplifying components such as transistors, triode vacuum tubes (valves), and tunnel diodes.
Passive components can't introduce net energy into the circuit. They also can't rely on a source of power, except for what is 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). Passive components include two-terminal components such as resistors, capacitors, inductors, and transformers.
Electromechanical components can carry out electrical operations by using moving parts or by using electrical connections
Most passive components with more than two terminals can be described in terms of two-port parameters that satisfy the principle of reciprocity—though there are rare exceptions.[2] In contrast, active components (with more than two terminals) generally lack that property.
Active components
Semiconductors
Diodes
Conduct electricity easily in one direction, among more specific behaviors.
Tunnel diode - very fast diode based on quantum mechanical tunneling
Transistors
Transistors were considered the invention of the twentieth century that changed electronic circuits forever. A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power.
Components incapable of controlling current by means of another electrical signal are called passive devices. Resistors, capacitors, inductors, and transformers are all considered passive devices.
Resistors
SMD resistors on a backside of a PCB
Pass current in proportion to voltage (Ohm's law) and oppose current.
Power resistor – larger to safely dissipate heat generated
SIP or DIP resistor network – array of resistors in one package
Variable resistor
Rheostat – two-terminal variable resistor (often for high power)
Potentiometer – three-terminal variable resistor (variable voltage divider)
Trim pot – Small potentiometer, usually for internal adjustments
Thermistor – thermally sensitive resistor whose prime function is to exhibit a large, predictable and precise change in electrical resistance when subjected to a corresponding change in body temperature.
Some different capacitors for electronic equipment
Capacitors store and release electrical charge. They are used for filtering power supply lines, tuning resonant circuits, and for blocking DC voltages while passing AC signals, among numerous other uses.
Electrical components that pass charge in proportion to magnetism or magnetic flux, and have the ability to retain a previous resistive state, hence the name of Memory plus Resistor.
LC Network – forms an LC circuit, used in tunable transformers and RFI filters.
Transducers, sensors, detectors
Transducers generate physical effects when driven by an electrical signal, or vice versa.
Sensors (detectors) are transducers that react to environmental conditions by changing their electrical properties or generating an electrical signal.
The transducers listed here are single electronic components (as opposed to complete assemblies), and are passive (see Semiconductors and Tubes for active ones). Only the most common ones are listed here.
Counterfeit electronic components are electronic parts that are misrepresented as to their origins or quality. Counterfeiting of electronic components can be an infringement of the legitimate producer's trademark rights. Since counterfeit parts often have inferior specifications and quality, they may represent a hazard if incorporated into critical systems such as aircraft navigation, life support, military equipment, or space vehicles.
The marketing of electronic components has been commoditized, making it easier for the counterfeiter to introduce substandard and counterfeit devices into the supply chain.
Supply chain for electronic components
OCM (Original Component Manufacturers)
Original Component Manufacturers design, market, and manufacture individual components
Franchise Distributor: Companies who are governed by a contract who have been authorized to sell OCM material.
Independent Distributor - Commonly known as electronic component "Brokers"
Wholesale Distributor: Companies who speculatively purchase excess inventories from component end-users and facilitate the redistribution of surplus, excess, and obsolete inventory.
Market forces facilitating trends
According to a January 2010 study by the US Department of Commerce, Bureau of Industry and Security the number of counterfeit incidents reported grew from 3,868 in 2005 to 9,356 in 2008. Respondents to the survey cited the two most common types of counterfeit components were blatant fakes and used product re-marked as higher grade. This survey had 387 respondents representing all facets of the electronic component supply chain. All facets of the supply chain reported instances of counterfeit product.[1] The World Semiconductor Trade Statistics estimates the global TAM for semiconductors will be in excess of $200 billion, thus the 387 respondents provide quantitative results for only a small portion of the total market.
This increase in instances of counterfeit products entering the supply chain has been made possible by fundamental changes to the supply chain for electronic components as characterized by the following:
Globalization
Dot-Com boom-Bust – The massive investment in telecommunications and data bandwidth during the dot-com bubble made communication tools and services available at a very low cost to business.
Outsourcing and off-shoring – The gradual shift of manufacturing from North American and Europe to the Far East facilitates technology transfer and awareness.
IT System interoperability – Adoption of the Windows operating system ensured that all computer users could easily and efficiently share information.[citation needed]
Global shipping companies – FedEx, UPS, and DHL refined their business offerings to provide relatively inexpensive shipping for small packages.
December 11, 2001, China was admitted to the WTO which would ultimately result in lifting the ban on exports by non-government-owned and controlled business entities.[2]
Global E-Waste handling
In late 1989, in response to public outcry against exporting and dumping of hazardous wastes from developed countries to developing countries, the Basel Convention was adopted in Basel, Switzerland.[3] In the decades following this convention, most of the developed countries have adopted this convention with the major exception of the USA. During this period the United States has continued to export its hazardous e-waste to the developing world, primarily China, where e-waste recycling has become a way of life, despite its toxic effect on the people processing this waste.[4] This e-waste provides the valuable raw materials for today's counterfeiter.
Examples and counterfeiting techniques
Non-functional units
Sanding & Remarking
Blacktopping & Remarking
Device substitution
Die salvaging
Manufacturing rejects
Component Lead Re-attachment
Relabeling boxes
These counterfeiting techniques are in constant improvement.
Counterfeit avoidance strategies
Procurement and Inspection
By utilizing multiple different types of incoming inspection most counterfeit components can be discovered.
DNA marking. Botanical DNA as developed by Applied DNA Sciences and required by the DoD's Defense Logistic Agency for certain High Risk microcircuits to determine authenticity or provenance. Unique and un-copyable marks applied by manufacturer and/or distributor.
Visual External Inspection for Signs of Resurfacing
Visual Microscopic Inspection of Encapsulant Finish and Lead Surfaces
X-Ray Inspection
By comparing the internal structure (of a homogeneous sample, same date & lot code) of electronic components certain types of counterfeit parts can be discovered. The "blatant fake" counterfeit devices exhibit vast differences in internal structure including, but not limited to different Die Frames and Different Wire Bonding.
X-RF Inspection
In the wake of the RoHS initiative, X-ray fluorescence spectroscopy can be used to confirm RoHS status which is often overlooked by counterfeiters.
Decapsulation
By removing the external packaging on a semiconductor and exposing the semiconductor wafer or die microscopic inspection of brand marks, trade marks, and laser die etching can be used to determine authenticity.
Chemical
Technique utilizing heated acid to expose wafer or die packaged in plastics or resins
Mechanical
Technique utilizing cutting, cracking, or chipping the ceramic or metal to expose wafer or die for inspection.
SAM (Scanning Acoustic Microscopy)
A Scanning acoustic microscope can be used to discover evidence of resurfacing and blacktopping by revealing laser etching below blacktop material
Parametric Testing a.k.a. Curve Tracing
An inexpensive and expedient method to determine of a sample of product has identical electrical characteristics.
Gross Leak and Fine Lead (Hermetically Sealed Components)
Functional Electrical Testing
QPL - Qualified Product List (Military Product)
QML - Qualified Manufacturers List (Military Product)
QSLD - Qualified Suppliers List of Distributors (Military Product)
QTSL - Qualified Testing Suppliers List (Military Product)
Stereo & Metallurgical Microscopes
Solderability Test Machine
Purchasing policies and procedures
As the instances of counterfeit and substandard products continue to increase, industry is beginning to address these issues through development and implementation of industry standards. As the majority of the counterfeit components were entering the supply chain though unknowing, unsophisticated, and unaware Independent Distributors (Component Brokers).
Continued work on awareness and industry standards continued with the formation of the G-19 Counterfeit Electronic Components Committee with representatives from all components of the supply chain.[6] In April 2009 SAE International released AS5553 Counterfeit Electronic Parts; Avoidance, Detection, Mitigation, and Disposition.
SAE International (SAE), has implemented new standards to prevent the dangers associated with the growing threat of counterfeiting, as have other Independent Distributors. Smith & Associates now has a certified anti-counterfeiting lab to help monitor for non-conforming parts. AS6081 was issued in November 2012 and was adopted by the DOD. This standard provides uniform requirements, practices, and methods to mitigate the risks of purchasing and supplying fraudulent or counterfeit electronic parts for distributors. This standard requires organizations involved with the purchase, acceptance, and distribution of such parts to have a quality management system in place, to communicate and document contract provisions that establish purchasing controls, and to retain appropriate records for supply chain traceability. In addition, AS6081 requires the purchased products to be verified through external visual inspections and radiological examinations.[8]
While AS6081 covers distribution of components, AS5553A provides similar certification for manufacturers. Originally implemented in January 2013 in response to the increasing volume of fraudulent and counterfeit parts entering the aerospace supply chain, AS5553A was expanded to mitigate such risk on a global scale with regard to various sectors. Many of the requirements of AS5553A are similar to AS6081 and likewise aim to prevent the receipt and installation of fraudulent or counterfeit parts through uniform requirements, practices, and methods
XXX . V00 Digital transformation: online guide to digital business transformation
Digital transformation is the profound transformation of business and organizational activities, processes, competencies and models to fully leverage the changes and opportunities of a mix of digital technologies and their accelerating impact across society in a strategic and prioritized way, with present and future shifts in mind. While digital transformation is predominantly used in a business context, it also impacts other organizations such as governments, public sector agencies and organizations which are involved in tackling societal challenges such as pollution and aging populations by leveraging one or more of these existing and emerging technologies. In some countries, such as Japan, digital transformation even aims to impact all aspects of life with the country’s Society 5.0 initiative, which goes far beyond the limited Industry 4.0 vision in other countries.
In the scope of this digital transformation overview, we mainly look at the business dimension. The mentioned development of new competencies revolves around the capacities to be more agile, people-oriented, innovative, customer-centric, streamlined, efficient and able to induce/leverage opportunities to change the status quo and tap into new information- and service-driven revenues. Digital transformation efforts and strategies are often more urgent and present in markets with a high degree of commoditization.
Present and future shifts and changes, leading to the necessity of a faster deployment of a digital transformation strategy, can be induced by several causes, often at the same time, on the levels of customer behavior and expectations, new economic realities, societal shifts (e.g. aging populations), ecosystem/industry disruption and (the accelerating adoption and innovation regarding) emerging or existing digital technologies. In practice, end-to-end customer experience optimization, operational flexibility and innovation, are key drivers of digital transformation, along with the development of new revenue sources and information-powered ecosystems of value, leading to business model transformations. Digital transformation is a journey with multiple connected intermediary goals, in the end striving towards continuous optimization across processes, divisions and the business ecosystem of a hyper-connected age where building the right bridges in function of that journey is key to succeed.
A digital transformation strategy aims to create the capabilities of fully leveraging the possibilities and opportunities of new technologies and their impact faster, better and in more innovative way in the future. A digital transformation journey needs a staged approach with a clear roadmap, involving a variety of stakeholders, beyond silos and internal/external limitations. This roadmap takes into account that end goals will continue to move as digital transformation de facto is an ongoing journey, as is change and digital innovation. In this online guide we explore the essence of digital transformation as a vision to take this journey, its evolutions and how it is present across various business processes and industries.
Digital business transformation – a holistic approach
Digital technologies – and the ways we use them in our personal lives, work and society – have changed the face of business and will continue to do so. This has always been so but the pace at which it is happening is accelerating and faster than the pace of transformation in organizations.
Digital transformation is not just about disruption or technology.
Digital transformation is probably not the best term to describe the realities it covers. Some prefer to use the term digital business transformation, which is more in line with the business aspect. However, as an umbrella term, digital transformation is also used for changes in meanings that are not about business in the strict sense but about evolutions and changes in, for instance, government and society.
This guide is about mainly about digital business transformation. In other words: about transformation in a context of digital business where there is a decentralizing shift of focus towards the edges of the enterprise ecosystem. The customer in the broadest sense (external and internal) is a leading dimension in this equation with customer experience, worker satisfaction, stakeholder value/outcomes, partnerships and a clear customer-centric approach as components.
Technological evolutions and technologies, ranging from the cloud, Big Data, analytics, artificial intelligence and mobile/mobility (a key game changer) to the IoT and more recent emerging technological realities are 1) enablers of digital transformation and/or, 2) causes of digital transformation needs (among others as they impact behavior of consumers or reshape entire industries such as manufacturing), and/or 3) accelerators of innovation and transformation. Yet, technology is only part of the equation as digital transformation is by definition holistic.
Digital transformation and hyper-connectedness: focus on the edges
Customer and customer experience, purpose and end goals, partners, stakeholders, the last mile of processes and disruption often sit and occur at these edges and are key for digital transformation. Sometimes digital transformation is even narrowed down to customer experience alone but, strictly speaking, this a mistake, leaving out several other aspects.
The end goals of the business, customers and stakeholders, however, do drive the agenda. The central role of the organization is to connect the dots and overcome internal silos in all areas in order to reach these different goals as interconnectedness is the norm. In other words: although the focus shift towards the edges, the central capabilities are realized in order to work faster and better for and at the edges. This happens for instance at organizational (integrated, ecosystems), technological (an ‘as-a-service approach’, cloud and agility enablers) and at a a cultural level. The movement towards the edges also reflects in technologies and the decentralization of work and business models.
From a technology perspective think about how data analysis is moving to the edge, the decentralization of information management, the shifts in security towards the endpoints, the impact of the Internet of Things and much more.
Still, it does not mean that strategic decisions move to the edges or that digital transformation is only possibly in organizations with “new” organizational models. Enterprise-wide digital transformation requires leadership, regardless of how it is organized and as long as the holistic approach towards the goals with the edges in mind prevails over internal silos and de facto gaps between reality and perception. In practice we see that pilot projects on the way to a more holistic and enterprise-wide approach often happen bottom-up, ad hoc or in specific departments. This is normal, typical in early stages but, if not followed through on a broader level, a potential risk for long-term success.