Revision topic 1

SensorsAnalogue and Digital

Control

Example question

What is a sensor exactly?

• Sensors measure the physical world and translate into an analogue electrical signal.

• Examples are:– Light – Sound– Temperature– Pressure– Acceleration– Motion– Heat

Value = Analogue value that varies continuously

Analogue and Digital• Analogue signals use a

continuous range of values – like those from a sensor.

• Digital signals have discrete values, such as on/off or 0/1. Inbetween values are not used.

SensorAnalog to

Digital Converter

Computer

Monitoring and Control

• We can’t control the weather• We just measure - Monitoring

• We do control machines• The key concept is feedback

Feedback and control

Sensor in the arm

Analogue to digital converter Computer

Program

Sets control values

Digital to Analogue converter

Motor/ Actuator in

the arm

Example question

Mark Scheme Answers

Follow up question

Mark Scheme Answers