Electrical and Electronic Systems
How electronic products work: electrical versus electronic systems, analogue and digital signals, the input, process and output blocks, and the microcontrollers and components that make them run.
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Systems that use electricity
An electrical system uses electricity to do a simple job, such as a circuit that lights a lamp when a switch is closed. An electronic system does more: it uses small components to process signals and make decisions. Most electronic systems follow the same pattern of an input, a process and an output. This module looks at how they work.
Analogue and digital terms
Learn these four terms before you study electronic systems.
Analogue or digital?
Electronic systems handle two kinds of signal.
Why a microcontroller
Explain why choices are made. A microcontroller is used because one chip can be reprogrammed to do many different jobs, which saves designing a new circuit each time. Digital signals are reliable because they only have to tell on from off, while analogue signals carry more detail but pick up more noise.
Match the component
- a switch
- a light-dependent resistor
- an LED
- a buzzer
- an input that is turned on by a user
- an input that detects how bright it is
- an output that gives light
- an output that makes a sound
Match the term
- an electrical system
- an electronic system
- an analogue signal
- a digital signal
- uses electricity to do a simple job like lighting a lamp
- uses small components to process signals and decide
- a signal that varies smoothly and can take any value
- a signal that has only two states, on or off
What is a digital signal?
What is a digital signal?
- A signal that has only two states, on or off.
- A signal that varies smoothly and can take any value.
- A signal made by gears and levers.
- A signal sent without wires.
Spot the inputs
Select the TWO input components.
- A switch.
- A light-dependent resistor.
- An LED.
- A buzzer.
Order the signal flow
Put the flow of a signal through an electronic system in order, earliest first.
- A sensor detects a change
- The microcontroller processes the signal
- It decides what to do
- The output component acts
Summarise the system
An _____ system uses small components to process signals, unlike a simple electrical circuit. A signal that varies smoothly is called _____, while a signal with only two states, on or off, is called _____. The processing is usually done by a _____, which can be reprogrammed for different jobs. A light-dependent resistor is an example of an _____ component.
Count the states
A digital signal has how many states: on and off?
Find the outputs
Tap the TWO output components.
- LED
- Switch
- Buzzer
- Light-dependent resistor
- Microcontroller
Input, process or output?
Decide which block each component belongs to.
- A thermistor that detects the temperature of a room
- A microcontroller that decides when to switch a fan on
- A motor that turns to open a window
Explain the signals
Explain the difference between an analogue signal and a digital signal, and give an example of where each might be used.
- Explain what an analogue signal is
- Explain what a digital signal is
- Give an example of where each is used