Input & Output Devices
Lerne es beim Spielen
Beantworte diese Fragen für Energie, dann angle und erkunde. Kein Konto nötig.
Lektionsnotizen
Input Devices
- Input devices are hardware components that allow users to interact with a computer system by inputting data or commands.
- Barcode scanner: reads barcodes to capture product information; used in supermarkets, warehouses, libraries for quick and accurate stock/checkout.
- Digital camera: captures photographs/videos as digital images; used in photography, smartphones, webcams for high-quality visual content.
- Keyboard: inputs text and commands by pressing keys; used with computers, tablets, laptops for typing, data entry, and software control.
- Microphone: captures analogue sound and converts it into digital signals; used in recording studios, smartphones, computers for audio recording and voice communication.
- Optical mouse: moves the cursor based on hand movements over a surface; used with computers and laptops for precise control and navigation.
- QR code scanner: reads QR codes to access stored information; used in retail shops and mobile apps for quick retrieval of website links or product info.
- Touch screens – three types: resistive (press flexible layer; ATMs, older devices), infra-red (interrupts IR beams; kiosks, large displays), capacitive (electrical charge change; modern smartphones, tablets, multi-touch).
- 2D scanner: captures flat images of documents/photos; used in offices, libraries, schools for digitisation.
- 3D scanner: captures detailed 3D shapes and dimensions; used in manufacturing, design, medical imaging for digital models.
Output Devices
- Output devices receive information from a computer system and present it to the user in an understandable form.
- Actuator: converts energy into motion; used to make robot arms move, open valves, rotate motors – essential in systems requiring movement.
- DLP projector: projects images/video by shining light through tiny mirrors; used in cinemas, classrooms, large presentations for high-quality images.
- Inkjet printer: prints text/images by spraying tiny ink droplets; used at home, schools, offices – low cost compared to other printers.
- Laser printer: heat from a laser fuses toner onto paper; used in offices and schools for high-quality, fast prints.
- LED screen: displays images/video using tiny LEDs; used in TVs, monitors, smartphones – bright, energy efficient, thin.
- LCD projector: projects images/video by shining light through liquid crystal panels; used in offices, classrooms, home cinemas – bright, good quality/affordability balance.
- LCD screen: displays images/video using liquid crystals with a backlight; used in TVs, monitors, smartphones, laptops – energy efficient, thin, sharp, lightweight.
- Speaker: converts electrical signals into analogue sound waves; used in TVs, radios, smartphones – multiple shapes and sizes.
- 3D printer: adds thin layers of plastic to form a three-dimensional object; used in manufacturing, medicine, education, home for prototypes and custom parts.
Choosing the Right Device
- User Needs: consider tasks – a graphic designer may need a graphics tablet, a data entry clerk a keyboard with number pad.
- User Skills: touch screen may be more intuitive for some, mouse and keyboard for others.
- Environment: wireless mouse for clutter-free office, wired mouse for public computer lab to prevent theft.
- Cost: higher-end devices have more features but are more expensive; consider budget and whether extra features are worth the cost.
Sensors – Input Devices for Monitoring and Control
- Sensors are input devices that measure a physical property of the environment (e.g., light, temperature, movement).
- Monitoring system: tracks the state of a system, gathers data, may issue warning messages.
- Control system: controls the system based on sensor input – e.g., if water temperature in a fish tank falls below acceptable level, a heater is switched on.
- Feedback loop: outputs are recycled and used as inputs, creating a continuous cycle (e.g., heater switches off when temperature is within range).
Types of Sensors
- Acoustic: measures sound levels; used to detect changes in industrial machinery, monitor noise pollution, security systems.
- Accelerometer: measures acceleration rate, tilt, vibration; used in vehicles to deploy safety features, in phones to detect orientation.
- Flow: measures rate of gas, liquid or powder flow; used to detect changes in flow through pipes in water systems.
- Gas: detects presence of a gas (e.g., carbon monoxide); used in confined spaces, fixing gas leaks.
- Humidity: measures levels of water vapour; used to monitor humidity in greenhouses.
- Infra-red: detects motion or heat source; used in security systems (break beam), emergency services to detect people.
- Level: measures liquid levels; used in car petrol tanks, water tanks, leak detection.
- Light: measures light levels; used to automatically switch on street lights/headlights when dark.
- Magnetic field: detects presence and strength; used in anti-lock braking systems, monitoring rotating machinery.
- Moisture: measures presence and levels of moisture; used in soil monitoring, dampness in buildings.
- pH: measures acidity or alkalinity; used in soil monitoring for optimum growing conditions, chemical processes.
- Pressure: measures gas, liquid or physical pressure; used in tyre pressure monitoring, pipe pressure in manufacturing.
- Proximity: measures distance; used in robotics for object positioning, safety systems to prevent collisions.
- Temperature: measures temperature; used to maintain temperature in swimming pools, control chemical processes.
Worked Example – Sensors
- Question: What type of sensor would be used to help drivers when reversing? Options: A Motion, B Infra-red, C Light, D Proximity. Answer: D Proximity.
- Question: Is this a monitoring system or a control system? Options: A Monitoring, B Control. Answer: B Control.
Overview of input and output devices, including sensors.
Feedback loop in a control system: sensor → processor → actuator, with feedback.
Folien
Sign up free to view the lesson slides
Step through every slide for this topic — plus flashcards and revision notes — with a free account.
Übungsfragen
Gratis-Vorschau — 8 von 57 Fragen. Registriere dich, um alle zu sehen.
1.Which of the following is an input device?
Easy- ASpeaker
- BLaser printer
- CBarcode scanner
- DLED screen
2.Which output device converts electrical signals into analogue sound waves?
Easy- AActuator
- BSpeaker
- CMicrophone
- DDLP projector
3.A sensor that measures acceleration rate, tilt, and vibration is called:
Easy- AAcoustic sensor
- BAccelerometer
- CPressure sensor
- DProximity sensor
4.Which type of touch screen detects touch through changes in electrical charge on the screen surface?
Medium- AResistive
- BInfra-red
- CCapacitive
- DOptical
5.A greenhouse uses a sensor to monitor water vapour levels. Which sensor is most suitable?
Medium- AHumidity sensor
- BMoisture sensor
- CTemperature sensor
- DLight sensor
6.Which of the following is an advantage of an inkjet printer compared to a laser printer?
Easy- AFaster print speed
- BHigher quality prints
- CLower cost
- DUses toner powder
7.In a control system, a sensor measures the water temperature in a fish tank. When the temperature falls below a set point, a heater is switched on. This is an example of:
Medium- AMonitoring system
- BFeedback loop
- COpen-loop system
- DManual control
8.Which sensor would be most appropriate for a system that detects intruders by sensing body heat?
Easy- AInfra-red sensor
- BMotion sensor
- CAcoustic sensor
- DPressure sensor
Unlock all 57 questions & more
Erstelle ein Gratis-Konto, um alle Fragen, Folien, Karteikarten und Lernnotizen zu diesem Thema zu sehen.