Outputs

allow a system to present information back into the ‘real’ world. Examples can be seen everywhere, from car indicators to doorbell buzzers or information displays.

Purpose of output devices

Light outputs

Light can be created using :

when flows through the it heats up and light is produced
filament lamps are increasingly being replaced with energy-saving alternatives, such as

The standard electrical symbol for a lamp alongside a photographs of a small indicator light bulb and an incandescent light bulb. — Figure caption,
Lamp - Used on control panels as an indicator or to provide illumination

Sound outputs

Sound can be produced using or .

Buzzers

buzzers have an inside a plastic case
when current flows through them they produce a buzzing sound, often around 400 Hertz (Hz) in depending on the type of buzzer used
examples of their use include in doorbells and alarms

Speakers

speakers produce sound using
they usually require a to provide a signal that they can use, such as an audio
the correct speaker value must always be used to prevent damage to the driver circuit