NAND Flash – Flash memory is an electronic (solid-state) non-volatile computer memory storage medium that can be electrically erased and reprogrammed. The two main types of flash memory are named after the NAND and NOR logic gates. The individual flash memory cells, consisting of floating-gate MOSFETs (floating-gate metal-oxide-semiconductor field-effect transistors), exhibit internal characteristics similar to those of the corresponding gates.

Nanoelectronics – Nanoelectronics refers to the use of nanotechnology in electronic components. The term covers a diverse set of devices and materials, with the common characteristic that they are so small that inter-atomic interactions and quantum mechanical properties need to be studied extensively. Some of these candidates include: hybrid molecular/semiconductor electronics, one-dimensional nanotubes/nanowires (e.g. Silicon nanowires or Carbon nanotubes) or advanced molecular electronics.

Nanoelectromechanical systems (NEMS) – Nanoelectromechanical systems (NEMS) are a class of devices integrating electrical and mechanical functionality on the nanoscale. NEMS form the next logical miniaturisation step from so-called microelectromechanical systems, or MEMS devices. NEMS typically integrate transistor-like nanoelectronics with mechanical actuators, pumps, or motors, and may thereby form physical, biological, and chemical sensors. The name derives from typical device dimensions in the nanometer range, leading to low mass, high mechanical resonance frequencies, potentially large quantum mechanical effects such as zero point motion, and a high surface-to-volume ratio useful for surface-based sensing mechanisms. Applications include accelerometers and sensors to detect chemical substances in the air.

Natural solution – is the solution of the differential equation a1dx(t)dt+a2x(t)=f(t) when forcing function f(t) is set equal to zero, so the differential equation looks a1dx(t)dt+a2x(t)=0

Near-Field Communication (NFC) – Near-field communication (NFC) is a set of communication protocols that enable two electronic devices, one of which is usually a portable device such as a smartphone, to establish communication by bringing them within 4 cm (1​1⁄2 in) of each other. NFC devices are used in contactless payment systems, similar to those used in credit cards and electronic ticket smart cards and allow mobile payment to replace or supplement these systems. This is sometimes referred to as NFC/CTLS (contactless) or CTLS NFC. NFC is used for social networking, for sharing contacts, photos, videos or files. NFC-enabled devices can act as electronic identity documents and keycards. NFC offers a low-speed connection with simple setup that can be used to bootstrap more capable wireless connections.

Newton (N) – is the unit of force, described by the formula 1N = 1kg*1msec2. 1 N is the amount of force applied to  the object with mass of 1 kg, makes object move with acceleration of 1msec2.

Node – is a junction of several branches.

Node-Voltage Method – is a method of analysis in circuit theory, based on calculation of node voltages as independent variables. For the circuit containing N nodes its possible to construct N-1 independent equations.

Non-linear circuit elements – are circuit elements, characterised with non-linear functional  relationshipi=f(v).

Non-volatile Memory (NVM) – Non-volatile memory (NVM) or non-volatile storage is a type of computer memory that can retrieve stored information even after having been power cycled. In contrast, volatile memory needs constant power in order to retain data. Examples of non-volatile memory include flash memory, read-only memory (ROM), ferroelectric RAM, most types of magnetic computer storage devices (e.g. hard disk drives, floppy disks, and magnetic tape), optical discs, and early computer storage methods such as paper tape and punched cards.


Ohm – is a resistance unit, Ω, and defined by the formula 1Ω=1VA.

Ohmmeter – is a device, that can measure resistance of a circuit elements, connected in parallel.

Ohm’s law – Ohm’s law states that the voltage across the circuit element is proportional to the current flowing through it. V=RI. The aspect of this ratio is called resistance and measured in Ohms (Ω).

One-phase current – is a current that can be described with a formula . Read more

One-port network – is a representation of a part of a circuit as a two-terminal device, characterised by IV characteristic.

Open circuit voltage – is a Thenevin equivalent current.

Optical communication systemis a system characterised with a large capacity to carry information. It can be used  in any application where transfer of the information is required from one place to another. And can be classified into two categories – guided and unguided optical systems. Read more.

Optoelectronics – Optoelectronics (or optronics) is the study and application of electronic devices and systems that source, detect and control light, usually considered a sub-field of photonics. In this context, light often includes invisible forms of radiation such as gamma rays, X-rays, ultraviolet and infrared, in addition to visible light. Optoelectronic devices are electrical-to-optical or optical-to-electrical transducers, or instruments that use such devices in their operation. Electro-optics is often erroneously used as a synonym, but is a wider branch of physics that concerns all interactions between light and electric fields, whether or not they form part of an electronic device.

Organic Light Emitting Diode (OLED) – An organic light-emitting diode (OLED or Organic LED), also known as an organic EL (organic electroluminescent) diode, is a light-emitting diode (LED) in which the emissive electroluminescent layer is a film of organic compound that emits light in response to an electric current. This organic layer is situated between two electrodes; typically, at least one of these electrodes is transparent. OLEDs are used to create digital displays in devices such as television screens, computer monitors, portable systems such as smartphones, handheld game consoles and PDAs. A major area of research is the development of white OLED devices for use in solid-state lighting applications.

Original Equipment Manufacturer (OEM) – A somewhat misleading term used to describe a company that has a special relationship with computer and IT producers. OEMs are typically manufacturers who resell another company’s product under their own name and branding. When a computer technology producer manufacturers its product, for example, a computer graphics card, they will usually make two or more versions of the product. One version is distributed by the manufacturer direct to the consumer retail market, using its own branding and offering its own warranty and support. Other versions of the manufactured product will be distributed through the manufacturer’s OEM and authorised reseller distribution channels. Usually OEM products are the same quality as the retail versions, but warranties may be different, the manual and bundled software may be non-existent, and the cables and connectors required for installation might not be included. In some cases it may be large quantities of the product purchased in bulk by the OEM for mass-production of pre-built systems.

Output capacitance – specifying the collector-emitter capacitance, when the gate is shorted to emitter.

Overdamped solution – is the solution of the differential equation, expressed the following way xn(t)=K1eα1t+K2eα2t. Here constants α1=1τ1and α2=1τ2.


Passives – Passivity is a property of engineering systems, used in a variety of engineering disciplines, but most commonly found in analogue electronics and control systems. A passive component, depending on field, may be either a component that consumes (but does not produce) energy (thermodynamic passivity), or a component that is incapable of power gain (incremental passivity). A component that is not passive is called an active component. An electronic circuit consisting entirely of passive components is called a passive circuit (and has the same properties as a passive component). Used out-of-context and without a qualifier, the term passive is ambiguous. Typically, analogue designers use this term to refer to incrementally passive components and systems, while control systems engineers will use this to refer to thermodynamically passive ones.

Peak collector repetitive current – describes the high peak current that can IGBT can hold off under the transient conditions.

Peak forward blocking voltage – determines the repetitive peak off-state anode to cathode voltage, when the gate terminal is open circuited, or with certain reverse voltage between the gate and cathode.

Peak forward gate current – is the peak value of current flowing forward direction between gate and cathode.

Peak forward gate voltage – is the peak value of the voltage in forward direction between gate and cathode.

Peak forward leakage current – is a peak value of off-state current through a device in conditions of applied forward voltage.

Peak gate reverse power dissipation – is the peak value of allowable power dissipation in the reverse direction between gate and cathode within certain period of time.

Peak on-state current – is a peak-value of a non-repetitive on-state current (with 50 or 60 Hz).

Peak on-state voltage – is a peak value of a voltage drop, when on-state current is applied (50 or 60 Hz).

Peak reverse blocking voltage – is a repetitive peak reverse anode to cathode voltage applicable on each cycle, where the gate terminal is open circuited.

Peak reverse gate voltage – is the peak value of the reverse voltage between gate and cathode.

Peak reverse leakage current – is a peak value for reverse current when in the condition of applied reversed voltage.

Periodic signals – a class of signals, used as an approximation of real processes, and described by the equation f(t)=f(t+nT), n=0,1,2...and T is a period of f(t).

Phasor – is complex vector that expresses a sinusoid signal, represented by the expression Acos(ωt+ϕ)=ReAej(ωt+ϕ).

Polarisation (of a plane wave) – is the direction of the vector of electric field. It can be fixed or change with time.

Poynting theorem – is an energy conservation law for electromagnetic fields and sources. Let’s consider an electromagnetic energy source, that can store electric and magnetic energy, can carry a power and transmit it or dissipate it. Then Poynting theorem says, that complex power Ps=12V(E·J*s+H*·Ms)dv, here Js and Ms are magnetic and electric sources.

Poynting vector – is the quantity that can be derived from the Poynting theorem and represented by the formula S=E×H*.

Positive-output Luo-converter – is a step down/up converter, consisting of the voltage source, resistive load, controllable switch, two inductances, two conductances, and diode. This converter can work in discontinuous mode. It’s output voltage and current can be calculated using  the formulas Vout=k1kVs and Iout=1kkIs, where Vs and Is are source voltage and current, k is the conduction duty.

Power (or electrical power) – is the work per unit of time. P=At. The power generated or dissipated by the circuit element, equal to the voltage and current through the element. Power is measured in Watts (W). P=VI. Power can have positive or negative sign. If the power sign in positive, then the charge was displaced from the higher potential to lower potential. If the power sign is negative, then the charge was displaced from the lower potential to higher potential. Direction of charge displacement indicated by the voltage sign.

Power factor – is the ratio of average power and apparent power, can be found using a formula: pf=PVrmsIrms.

Power Management Integrated Circuits (PMIC) – Power management integrated circuits (power management ICs or PMICs or PMU as unit) are integrated circuits for power management. Although PMIC refers to a wide range of chips (or modules in system-on-a-chip devices), most include several DC/DC converters or their control part. A PMIC is often included in battery-operated devices such as mobile phones and portable media players to decrease the amount of space required.

Power stored in the inductor – can be found by the formula P(t)=t(LI2(t)2).

Principle of superposition – is the principle in the theory of circuits, stating that in the circuit with N sources, every branch voltage an current is the sum of N voltages and currents that can be computed the following way: all but one source should be set equal to zero, and solve the circuit containing only one source.

Printed Circuit Board (PCB) – A printed circuit board (PCB) mechanically supports and electrically connects electronic components or electrical components using conductive tracks, pads and other features etched from one or more sheet layers of copper laminated onto and/or between sheet layers of a non-conductive substrate. Components are generally soldered onto the PCB to both electrically connect and mechanically fasten them to it.

Programmable Logic Controller (PLC) – A programmable logic controller (PLC) or programmable controller is an industrial digital computer which has been ruggedised and adapted for the control of manufacturing processes, such as assembly lines, or robotic devices, or any activity that requires high reliability control and ease of programming and process fault diagnosis. PLCs were first developed in the automobile manufacturing industry to provide flexible, ruggedised and easily programmable controllers to replace hard-wired relays, timers and sequencers. Since then, they have been widely adopted as high-reliability automation controllers suitable for harsh environments. A PLC is an example of a ‘hard’ real-time system since output results must be produced in response to input conditions within a limited time, otherwise unintended operation will result.

Propagation constant – see wave number.

Python – Python is an interpreted, high-level, general-purpose programming language. Created by Guido van Rossum and first released in 1991, Python’s design philosophy emphasises code readability with its notable use of significant whitespace. Its language constructs and object-oriented approach aim to help programmers write clear, logical code for small and large-scale projects.

PSPICE – is a commercially available adaptation of SPICE, suitable for personal computers.

PWM DC-DC full-bridge converter – is the electronic device consisting of voltage source, four controllable switches, two diodes, transformer and a load.

PWM DC-DC push-pull converter – is the electronic device consisting of two controllable switches, two diodes, voltage source, transformers and a load. The switches operates shifted here. When first switch is on, corresponding diode conducts, and vice versa for the second switch. When both switches are off – diodes are on and share the current.

Quarter-wave impedance transformer – is a device that matches the transmission line and the impedance. Read more.

Radio Frequency (RF) – Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around 20 kHz to around 300 GHz. This is roughly between the upper limit of audio frequencies and the lower limit of infrared frequencies; these are the frequencies at which energy from an oscillating current can radiate off a conductor into space as radio waves. Different sources specify different upper and lower bounds for the frequency range.

Radio-Frequency Identification (RFID) – Radio-frequency identification (RFID) uses electromagnetic fields to automatically identify and track tags attached to objects. The tags contain electronically stored information. Passive tags collect energy from a nearby RFID reader’s interrogating radio waves. Active tags have a local power source (such as a battery) and may operate hundreds of meters from the RFID reader. Unlike a barcode, the tags don’t need to be within the line of sight of the reader, so it may be embedded in the tracked object. RFID is one method of automatic identification and data capture (AIDC).

Random Access Memroy (RAM) – Random-access memory (RAM) is a form of computer memory that can be read and changed in any order, typically used to store working data and machine code. A random-access memory device allows data items to be read or written in almost the same amount of time irrespective of the physical location of data inside the memory. In contrast, with other direct-access data storage media such as hard disks, CD-RWs, DVD-RWs and the older magnetic tapes and drum memory, the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement.

Reactance – is a term used in connection to the complex impedance of the elements of the circuit. As soon as the complex impedance of the circuit can be written the following way: Z(jω)=Re(jω)+Im(jω).

Reactive power – is combined energy stored during the first half-cycle and recovered by the second half-cycle. Reactive power is usually applied to the combined energy of inductor or capacitor, and can be found using a formula Preac=VrmsIrmscos(θφ).

Real-Time Clock (RTC) – A real-time clock (RTC) is a computer clock (most often in the form of an integrated circuit) that keeps track of the current time. Although the term often refers to the devices in personal computers, servers and embedded systems, RTCs are present in almost any electronic device which needs to keep accurate time.

Real-Time Operating System (RTOS) – A real-time operating system (RTOS) is an operating system (OS) intended to serve real-time applications that process data as it comes in, typically without buffer delays. Processing time requirements (including any OS delay) are measured in tenths of seconds or shorter increments of time. A real-time system is a time bound system which has well defined fixed time constraints. Processing must be done within the defined constraints or the system will fail. They either are event driven or time sharing. Event driven systems switch between tasks based on their priorities while time sharing systems switch the task based on clock interrupts. Most RTOSs use a pre-emptive scheduling algorithm.

Rectification ratio – is a parameter showing the effectiveness of the rectification and  can be found using a formula δ=PdcPL.

Reflection coefficient – is the parameter describing amount of wave reflected in the medium, and can be found by the formula Γ=ηη0η+η0, where η=jwμγ is intrinsic impedance and γ=jωμε1jσωε is propagation constant.

Relays – A relay is an electrically operated switch. It consists of a set of input terminals for a single or multiple control signals, and a set of operating contact terminals. The switch may have any number of contacts in multiple contact forms, such as make contacts, break contacts, or combinations thereof. Relays are used where it is necessary to control a circuit by an independent low-power signal, or where several circuits must be controlled by one signal. Relays were first used in long-distance telegraph circuits as signal repeaters: they refresh the signal coming in from one circuit by transmitting it on another circuit. Relays were used extensively in telephone exchanges and early computers to perform logical operations.

Resistance – is a element of a circuit, characterised by the volt-ampere characteristics of the circuit (corresponding to the resistor). Magnitude of resistance depends on the properties of material. Current flowing through the element may cause energy dissipation. Read more.

Resistance Strain Gauges – devices, used in engineering, that are bonded to the surface of the object. Their resistance varies depending on the surface strain of the object. These devices can be used to measure stress, force, torque, pressure.

Resistive Throttle Position Sensor (TPS sensor) – is the circuit element, providing variable resistance, depending on the position of the throttle valve.

Resistivity – is the property of the material, defining the resistance of the circuit element. It is denoted by the symbol ρ. Resistivity is opposite to the property, called conductivity. For a cylindrical resistive element, resistivity is described by the formula ρ=RSl, where R is the radius of the element, S is the square of its cross section, and l is its length.

Resistors – A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. Resistors act to reduce current flow, and, at the same time, act to lower voltage levels within circuits. In electronic circuits, resistors are used to limit current flow, to adjust signal levels, bias active elements, and terminate transmission lines among other uses. High-power resistors, that can dissipate many watts of electrical power as heat, may be used as part of motor controls, in power distribution systems, or as test loads for generators. Fixed resistors have resistances that only change slightly with temperature, time or operating voltage. Variable resistors can be used to adjust circuit elements (such as a volume control or a lamp dimmer), or as sensing devices for heat, light, humidity, force, or chemical activity.

Restriction of Hazardous Substances Directive (RoHS) – The Restriction of Hazardous Substances Directive 2002/95/EC, (RoHS 1), short for Directive on the restriction of the use of certain hazardous substances in electrical and electronic equipment, was adopted in February 2003 by the European Union.

Reverse transfer capacitance – is a miller capacitance between gate and collector.

Ripple factor – is the measure of the ripple content, equal to the ratio of rms value of ac content of the load voltage to the average value. It can be found using a formula RF=VacVdc=FF21.

Rise time – term used in application to IGBT, is a time required for collector current to rise from 10% to 90% of its initial value.

RISC-V – RISC-V (pronounced ‘risk-five’) is an open-source hardware instruction set architecture (ISA) based on established reduced instruction set computer (RISC) principles. Unlike other academic designs which are optimised only for simplicity of exposition, the designers state that the RISC-V instruction set is for practical computers. It is said to have features to increase computer speed, yet reduce cost and power use. These include a load–store architecture, bit patterns to simplify the multiplexers in a CPU, simplified standards-based floating-point, a design that is architecturally neutral, and placing most-significant bits at a fixed location to speed sign extension. Sign extension is said to often be on the critical timing path.

RMS (root-mean-square) value – in the theory of signals is the value of the signal, taking into account fluctuations of the signal about its average value, and can be found by the formula xrms=1T0Tx(r)dr, where T is a period of a signal.

RMS on-state current – is a RMS value of on-state current that can be continuously applied to a device.

Rotating electrical machine – is a microelectromechanical system, operating on the laws of electric and magnetic fields, consisting of rotor, stator, and windings. One of the examples of microelectromechanical systems is rotating electric machines. The key role in the operation of electric machines is played by windings. Read More 


Second-order ordinary differential equation – is a differential equation of the forma2d2x(t)dt2+a1dx(t)dt+a0x(t)=F(t).

Semiconductors – are a class of materials characterised with electron conductivity. They are capable of changing their features depending on different external conditions (temperature, light, electromagnetic field and others). Semiconductors can be intrinsic and extrinsic. Read more.

Session Initiation Protocol (SIP) – The Session Initiation Protocol (SIP) is a signalling protocol used for initiating, maintaining, and terminating real-time sessions that include voice, video and messaging applications. SIP is used for signalling and controlling multimedia communication sessions in applications of Internet telephony for voice and video calls, in private IP telephone systems, in instant messaging over Internet Protocol (IP) networks as well as mobile phone calling over LTE (VoLTE).

Short-circuit current – is a Norton equivalent current.

Signalsare functions of one or several independent variables. There are two types of signals – discrete-time and continuous-time. Discrete-time signals are defined at the discrete moment of time and the mathematical function takes the discrete set of values. Read more.

Signal generator – is a device, allowing allowing a selection of waveform with amplitude and period.

Silicon Carbide (SiC) – Silicon carbide (SiC), also known as carborundum, is a semiconductor containing silicon and carbon. It occurs in nature as the extremely rare mineral moissanite. Synthetic SiC powder has been mass-produced since 1893 for use as an abrasive. Grains of silicon carbide can be bonded together by sintering to form very hard ceramics that are widely used in applications requiring high endurance, such as car brakes, car clutches and ceramic plates in bulletproof vests. Electronic applications of silicon carbide such as light-emitting diodes (LEDs) and detectors in early radios were first demonstrated around 1907. SiC is used in semiconductor electronics devices that operate at high temperatures or high voltages, or both. Large single crystals of silicon carbide can be grown by the Lely method and they can be cut into gems known as synthetic moissanite.

Silicon-controlled rectifier (SCR) – is a three-terminal device consisting of cathode, anode and gate, often synonymous to thyristor. In order to SCR conduct, the gate current should be applied in condition with positive anode-to-cathode voltage. It’s important for SCR operation that anode current remains positive.

Single-phase half-wave diode rectifier – is the device that converts AC signal into DC voltage. The simplest rectifier of this type consist of one diode, connected to secondary transformer, during the positive cycle of the transformer diode conducts, during the negative cycle diode stops conducting.

Single-phase full-wave rectifier – this device consists of centre-tapped transformer and two diodes. each diode conducts in certain cycle, what provides full rectification in the load.

Sink temperature – is a temperature of the certain point on the heatsink of the electronic device.

Skin depth – the depth to which most of the microwave power penetrates in the material, usually marked δs.

Solid State Drives (SSDs) – A solid-state drive (SSD) is a solid-state storage device that uses integrated circuit assemblies to store data persistently, typically using flash memory, and functioning as secondary storage in the hierarchy of computer storage. It is also sometimes called a solid-state device or a solid-state disk, although SSDs lack the physical spinning disks and movable read-write heads used in hard drives (‘HDD’) or floppy disks.

Source – is an element of electric circuit, that provides energy. Can be several types.

Source transformation – is a procedure used in circuit analysis for calculating equivalent circuits based on replacing existing voltage and current sources.

SPICE – is a circuit simulation program, that was developed at the University of California at Berkeley.

Static Random Access Memory (SRAM) – Static random-access memory (static RAM or SRAM) is a type of semiconductor random-access memory (RAM) that uses bistable latching circuitry (flip-flop) to store each bit. SRAM exhibits data remanence, but it is still volatile in the conventional sense that data is eventually lost when the memory is not powered. The term static differentiates SRAM from DRAM (dynamic random-access memory) which must be periodically refreshed. SRAM is faster and more expensive than DRAM; it is typically used for CPU cache while DRAM is used for a computer’s main memory.

Storage temperature – is the range of temperatures specifying maximal and minimal temperatures allowable for storage of an electronic device without electrical connections.

Substractive manufacturing – is a manufacturing method, opposite to additive manufacturing, where material layers are being cut away where they are not needed. The example of subtractive manufacturing is laser cutting.

Supervisory Control and Data Acquisition (SCADA) – Supervisory Control and Data Acquisition (SCADA) is a control system architecture that uses computers networked data communications and graphical user interfaces(GUI) for high-level process supervisory management, but uses other peripheral devices such as programmable logic controller (PLC) and discrete Proportional Integral Differentiator (PID) controllers to interface with the process plant or machinery. The use of SCADA has been also considered for management and operations of project-driven-process in construction.

Surface resistance – is the resistance of the conductor in the layer between outside and skin depth level. Surface resistance of the conductor can be found by the formula Rs=1σδs.

System-on-Chip (SoC) – A system on a chip or system on chip (SoC or SOC) is an integrated circuit (IC) that integrates all components of a computer or other electronic system into a single chip. It may contain digital, analogue, mixed-signal, and often radio-frequency functions—all on a single chip substrate. SoCs are very common in the mobile electronics market because of their low power consumption. A typical application is in the area of embedded systems. The contrast with a microcontroller is one of degree. Microcontrollers typically have under 100KB of RAM (often just a few kilobytes) and often really are single-chip-systems, whereas the term SoC is typically used for more powerful processors, capable of running software such as the desktop versions of Windows and Linux, which need external memory chips (flash, RAM) to be useful, and which are used with various external peripherals. In short, for larger systems, the term system on a chip is hyperbole, indicating technical direction more than reality: a high degree of chip integration, leading toward reduced manufacturing costs, and the production of smaller systems. Many systems are too complex to fit on just one chip built with a processor optimised for just one of the system’s tasks.

System-on-Module (SoM) – A system on a module (SOM) is a board-level circuit that integrates a system function in a single module. It may integrate digital and analog functions on a single board. A typical application is in the area of embedded systems. Unlike a single-board computer, a SOM serves a special function like a system on a chip (SoC). The device integrated in the SOM typically requires a high level of interconnection for reasons such as speed, timing, bus-width etc., in a highly integrated module. There are benefits in building a SOM, as for SoC; one notable result is to reduce the cost of the base board or the main PCB. Two other major advantages of SOMs are design-reuse and that they can be integrated into many embedded computer application.

Switches – In electrical engineering, a switch is an electrical component that can ‘make’ or ‘break’ an electrical circuit, interrupting the current or diverting it from one conductor to another. Switch has an internal mechanism which removes or restores the conductive path when it is being operated. It may be operated manually, for example, a light switch or a keyboard button, may be operated by a moving object such as a door, or may be operated by some sensing element for pressure, temperature or flow.


The Thenevin Theorem – the circuit composed of ideal voltage/current sources and linear resistors can be represented by equivalent circuit with equivalent voltage source veq in series with equivalent resistance req.

The Norton theorem – the circuit composed of ideal voltage/current sources and linear resistors can be represented by equivalent circuit with equivalent current source ieq in parallel with equivalent resistance req .

TensorFlow – TensorFlow is a free and open-source software library for dataflow and differentiable programming across a range of tasks. It is a symbolic maths library, and is also used for machine learning applications such as neural networks. It is used for both research and production at Google.‍

Tera Operations Per Second (TOPS) – Tera Operations Per Second (TOPS) is a common performance metric used for high-performance SoCs. TOPS per watt extends that measurement to describe performance efficiency. The higher the TOPS per watt the better and more efficient a chip is.

Thyristor – is a three-terminal device used in some power electronic circuits, including silicon-controlled rectifier (SRC), the triac, the gate turn-off thyristor (GTO), MOS-controlled thyristor and others. Thyristors are known by their capability work with large currents and blocking voltages, but relatively low switching frequencies.

Time constant – is the constant parameterain the differential equationa1dx(t)dt+a2x(t)=f(t), herea=a2a1=1τ.

Time-Sensitive Networking (TSN) – Time-Sensitive Networking (TSN) is a set of standards under development by the Time-Sensitive Networking task group of the IEEE 802.1 working group. The TSN task group was formed in November 2012 by renaming the existing Audio Video Bridging Task Group and continuing its work. The name changed as a result of extension of the working area of the standardisation group. The standards define mechanisms for the time-sensitive transmission of data over deterministic Ethernet networks.

Transfer function – also known as a system function, that serves as a relationship between output and input amplitude.

Transformer utilisation factor – is the measure of the rate of rectifying current, equal to the ratio of the DC output power to the transformer power rating and can be found using a formula TUF=PdcVsIs.

Transient analysis – is the analysis among to describe the current or voltage behaviour between two steady-state conditions.

Transient peak-reverse blocking voltage – is a non-repetitive peak reverse anode to cathode voltage, during the time period less than 5ms, when the gate is open circuited.

Transient response – is the circuit response for application current or voltage. The example of a transient response is when a switch is on or off in a circuit.

Transient thermal impedance – the change of temperature difference between two specified points at the end of the time interval and at the beginning of this interval that is causing the change of the temperature difference.

Transmission coefficient – is the parameter, showing the amount of the electromagnetic wave, that was transmitted through the medium, and can be found by the formula Τ=1+Γ=2ηη+η0, where η=jωμγ is an intrinsic impedance and γ=jωμε1jσωε is propagation constant.

Triac – is a thyristor used to conduct current in both directions, that is functionally equivalent to two antiparallel SCRs.

Triggering – see gating.

Turn-off delay time – term used in application  to IGBTs, and it is a time between 90% of gate voltage and 10% of collector voltage.

Turn-on delay time – is the time defined as a time between 10% gate voltage and 10% of the final collector current.


Universal Asynchronous Receiver-Transmitter (UART) – A universal asynchronous receiver-transmitter (UART) is a computer hardware device for asynchronous serial communication in which the data format and transmission speeds are configurable. The electric signalling levels and methods are handled by a driver circuit external to the UART. A UART is usually an individual (or part of an) integrated circuit (IC) used for serial communications over a computer or peripheral device serial port. One or more UART peripherals are commonly integrated in microcontroller chips. A related device, the universal synchronous and asynchronous receiver-transmitter (USART) also supports synchronous operation.


VAR controller – is a circuit where thyristor is used to switch capacitors or inductors in order control reactive power in the system.

Vector network analyzer – two (or four channel) receiver, processing phase and magnitude of transmitted and reflected  waves from the network.

Volt (V) – unit of electric potential or voltage, described by the formula 1V=1WA=1JC. Volt is a difference in potential between two points in a conductor, where electrical current equal to 1A dissipates power of 1W.

Voltmeter – is a device for measuring voltage across the circuit element.

Voltage divider – is the concept used in the circuit theory, that allows to calculate the proportion of voltage drop distribution around the circuit, consisting of several resistances connected in series. The elements of circuit are connected in series if they identical current flows through every element. Voltage divided rule is represented by the formula vn=RnR1+...+RnvS, where vS is a voltage of a voltage source.


Wave equation – see Helmholtz equation.

Wavelength – is a distance between two subsequent maxima on the wave considered at a fixed time, and can be found with the formula λ=2πk=2πvfω.

Wave number – is a propagation constant in wave equation k=ωμε. Propagation constant can be also complex and defined by the formula γ=α+jβ=jωμε1jσωε, here α is attenuation constant and β is phase constant.

Watt (W) – unit of power, described by the formula 1W=1J1sec. Power can be described as a rate of transmitting the energy.

Wattmeter – is a measuring device that can provide measurement of power dissipated through the circuit element.

Water resistor – is a combination of metal electrode and electrolytic solution (dilute solution of copper sulfate in deionised water), that can hold high voltage from modulator and dissipate average power.

Well implants – high energy ions providing low-resistance path to contacts of a device.

Wheatstone bridge – is a resistive circuit, that is usually used in measurement circuits.

Wind energy – one of the greatest potentially type of energy, estimated as 300TW to 780TW. Most wind energy is available on the open ocean.

W-band communication range – is the frequency range 75-100GHz, used in satellite communications, millimetre-wave radars, and some other applications.

X-band communication range – is a 7.0 -11.2 GHz band of frequencies in MW region of electromagnetic spectrum. This frequency band is used in the radar engineering, satellite communication and other applications.
Yield – in electronics engineering marked as Y, is the probability that the electronic device will work. It is related to the failure probability X the following via the formula X=1Y. If there is N components in a system, the yield of the system Ys can be found by the formula Ys=YNc.

Zener diode – is a type of diode whose properties depend on the voltage avalanche properties. It is used for regulation and voltage reference.

Zigzag dipole antenna – is an element of a log-periodic dipole antenna.