Looking at systems

What is a SYSTEM?The radiator makes the room warmer by turning ON when the temperature of the room is lower than required

The THERMOSTAT monitors and controls the temperature of the room.

If it’s too cold it turns the radiator ON.If it’s too hot it turns the radiator OFF.

The parts of the system

A heat sensor records the temperature – this is an INPUT

The thermostat then decides what to do – it PROCESSES the information

Then it either turns the radiator ON or OFF and gives out heat – this is an OUTPUT

This is an AUTOMATIC system because once the temperature has been set, the system works by itself.

The shower system

The INPUT to the system is hot and cold water

This is PROCESSED by the mixer control

The OUTPUT is warm water

This system involves a HUMAN in the control and monitoring process.

A computer system

What INPUTS can you have to a computer system?

What OUTPUTS can you have?

Input Process Output

Feedback

A shower uses FEEDBACK in the system.

If the water (output) is too hot, you can adjust it by turning the mixer control to add more cold water (input)

This change in the output by altering the input is called FEEDBACK

Cat is captured by web camera

Sensitivity level triggers software to start filming, take picture or sound alarm

Sensitivity can be set manually

Web camera sensing

Web camera sensing

Motion and sound can be sensed and used to trigger the system

Pictures or video are stored as small files

As the motion is captured, a short video or picture is taken or an alarm can be triggered

• What is happening as people move in front of the camera?

• How is the software sensing movement?

• How could this be used in real-life situations?

Web camera sensing