Zusammenfassung der Ressource
Sensors
- What is it?
- A motion
sensor
- What does it do?
- Detects movement to perform a task such
as opening a door
- How does it work?
- A camera looks for movement and when
it detects it it performs the task
- What is it?
- A light sensor
- What does it do?
- When hit by light, it performs a task such as
switching a device on
- How does it work?
- It uses the photons in light to generate electricity
or to change properties such as electrical
resistance
- What is it?
- A gas sensor
- What does it do?
- Detects when there is harmful
gas in the air
- How does it work?
- It has free electrons that are attracted to the surface when there are a lot
of oxygen particles in the air. When there is mostly another gas, they are
free again and conduct a current to sound an alarm
- What is it?
- A temperature sensor
- What does it do?
- Senses the
temperature of an
object
- How does it work?
- A change in temperature alters the voltage of one type of sensor.
Others work because their resistance is changed by the temperature
or in other ways.
- What is it?
- A proximity sensor
- What does it do?
- Senses when an object is close
to it without contact
- How does it work?
- It emits infrared light and
detects how many rays are
reflected back. The more rays,
the closer the object