External Component: Speaker

• External components of computer hardware: output devices

Speaker

• Device that converts electrical signals into sound
• Operates by vibrating a cone or diaphragm to move air and creates audible sound waves
• Passing an electrical signal through a coil in a magnetic field moves the coil and vibrates the cone to produce sound waves

Main Parts of a Loudspeaker

• Cone: Diaphragm converting mechanical motion to sound waves, attached to voice coil
• Voice Coil: Copper wire attached to cone, functions as an electromagnet creating a magnetic field when electrical signal passes through it, thus moves the cone
• Magnet: Permanent magnet around which the voice coil is wound and interacts with the magnetic field of the voice coil causes it to move

Speaker Types

• Dynamic Speaker: Common type using a magnetic field to move a cone-shaped diaphragm
• When alternating current (audio signal) is applied to the coil, diaphragm vibrates and creates audio
• Wireless Speaker: Receives audio signals via radio frequency (RF) waves, controlled by an app, adapts to mounting position
• Horn Speaker: Uses a horn to improve the efficiency of the speaker driver, matching impedance to air and allowing smooth sound wave transition

Plotter

• Type of printer technology and computer output device, creates high-quality large-format images, diagrams, and drawings on flat surfaces
• It uses pens, pencils, or other drawing tools to produce continuous, detailed lines from computer commands
• Plotters are used for printing large graphs, engineering drawings, business charts, construction maps, and architectural blueprints
• Can be a freestanding device with its own CPU or a computer peripheral

Plotter Applications

• Used primarily in technical drawing and CAD applications, as they provide the advantage of working on large paper sizes while maintaining high resolution
• These include architectural, engineering, graphic design, education, textile, advertising, research, mapping, and prototyping

Printer

• Device that accepts text and graphics output from a computer and transfers it onto paper
• History: Charles Babbage introduced first mechanical printer in 1822 and Inkjet printers were invented in the 1950s

History of Ink Jet Printer

• Inkjet printers produce digital images starting in the late 1970s from Canon, Epson, and Hewlett-Packard
• Images are composed of dots shot onto the page whereas dot matrix printers use a ribbon and pins, inkjet dots are smaller and faster

Ink Jet Printer

• Inkjet printers produce high-resolution prints with color accuracy and vary in size/capacity for small offices or high-volume environments
• In addition to printing, they offer functionalities for scanning, copying, and faxing, making them versatile tools

Benefits of Inkjet Printers

• High-Quality Output
• Cost-Effective
• Versatility
• Ease of use

Monitor

• A type of external hardware and output device used to display information from a computer's CPU and graphics card

Monitor Types

• Liquid Crystal Display (LCD): Flat panel display tech that uses liquid crystals
• Light Emitting Diode(LED): Semiconductor devices that produce light when electric current passes through, providing high contrast images, that is durable and thin with lower heat production and environmental impact
• Organic Light Emitting Diode (OLED): Solid-state device that emits light when electric current passes through, used in TVs and produce stunning images with lower production costs than LCDs, does not require a backlight
• Cathode-Ray Tube(CRT): Computer display using a vacuum tube and electron gun to produce images on a screen coated with phosphor dots, electron beams create visible images
• Plasma Monitor: Flat-panel display using tiny cells filled with ionized gas which turns into a plasma that emits light when electrically charged, creating an image

First Monitor Inventor

• Karl Ferdinand Braun: Credited with inventing the first monitor in 1897 which used a cathode ray tube (CRT) with fluorescent screen that produced light when electrons passed through it