A3.4 Introduction to electronic systems (HL Only)

Active electronic components

Electronic components that control the flow of electricity.

Ampere

An electrical current.

Analogue system (electronics)

An electronic system that has a permanently variable signal.

Binary digit

A binary digit has either a value of 0 or 1.

Buzzer

An electronic device that emits a buzzing noise when activated.

Capacitor

An electronic component used to store an electric charge.

Closed-loop system

A self-regulating, automated system where the output is considered feedback and acts as an input back into the system.

Current

The flow of electricity in a circuit that results from the movement of electrically charged particles.

Control circuit

A circuit that carries signals that direct the performance of a controller.

Digital system (electronics)

An electronic system that uses binary signals, i.e. 0 or 1, on or off.

Diode

An electronic device that allows the flow of current in one direction only.

Electronic circuit

A selection of electronic components joined together via a conducting material in a system that performs a function.

Electronic system

A system powered by electricity that receives an input as information, processes that information and produces a desired output.

Embedded system

A computerized system designed to perform a specific set of real-world functions.

Feedback loop

An essential element to create a closed system, a feedback loop is a process in which an output is "fed back" to the system as an input.

Hertz (Hz)

The standard unit of frequency in an electrical system. One hertz is equal to one cycle per second.

Fixed resistor

A resistor that has a defined value of electrical resistance that is not adjustable.

Frequency

The rate at which current changes from positive to negative per second in a signal measure in hertz (Hz).

Input

What is put into a system.

Input devices

A component of a system used to put information into that system. For example, a switch or a sensor.

Integrated circuit

A small component comprised of a self-contained electrical circuit that performs the same function as a larger circuit made from individual components.

Internet of Things (IoT)

Everyday objects and devices that contain computing devices that are interconnected through the internet, enabling them to send and receive data.

Light-emitting diode (LED)

An electronic device that allows the flow of current in one direction only, and glows when current runs through it.

Liquid crystal display (LCD)

An electronic device that consists of a flat panel display that uses liquid crystal molecules controlled by an electric field.

Logic gate

A device that performs a Boolean function in a digital system that controls whether an input signal can pass through to the output.

Microcontroller

An electronic device used to control specific operations in an embedded system. It is a compact integrated circuit.

Motor (electronics)

An electronic device that converts electrical energy into a rotary motion.

Ohm

A unit of electrical resistance.

Open-loop system

A control system that does not have any feedback.

Operational amplifier (op-amp)

An electronic device that amplifies weak signals.

Output

What comes out of a system.

Passive electronic components

Electronic components that do not have any control over the flow of electricity.

Power

The rate at which electrical energy is transferred by an electric circuit. See resistance.

Processing devices

Components that are responsible for interpreting, manipulating and storing data in an electronic system.

Programmable integrated circuit (PIC)

A small component comprised of a self-contained electrical circuit that performs the same function as a larger circuit made from individual components and that can be programmed to respond in a certain way.

Relay

An electronic device that is activated by current or a signal to open or close another circuit.

Resistance

The opposition to the flow of electrons in an electrical circuit that can be calculated as: resistance (R), voltage (V), and current (I) in an electrical circuit is known as Ohm's Law.

V = I × R

V = the voltage

I = the current (in amperes, abbreviated as "A")

R = the resistance (in ohms, abbreviated as "Ω")

Sensor

An electronic input device that detects or measures an input from the physical environment.

Signal conditioning

The processing of an analogue signal that prepares it for the next stage of processing.

Switch (electronics)

An electrical component used to connect or disconnect the conducting path in an electrical circuit.

Transistor

An electrical component that is a semiconductor and has three connections capable of regulating current or voltage flow and amplification.

Variable resistor

A resistor that has an adjustable value of electrical resistance.

Voltage

An electromotive force from a power source that pushes electrons through a circuit, also considered as electric pressure.

Watt

A unit of power equivalent to one joule per second