Systems And Controls

Question 1

Three elements in all systems:

Answer 1

Input ~ Process ~ Output
For a streetlight:
Light sensor ~ Switching ~ Light
This is the simplest a process can be

Question 2

Inputs

Answer 2

Electrical or mechanical sensors 
Use signals from environment
• light levels, temperature and pressure
Converts them into signals 
Examples:
Light dependant resistor (LDR)
Thermistor - temperature sensor
Switches

Question 3

Outputs

Answer 3

Part of an electronic system
Examples:
Lamps (never 'bulbs')
LEDs
Buzzers
Piezoelectric buzzers - car alarm (sense movement)
Loudspeakers

Question 4

Processors

Answer 4

Often performed by microcontrollers
Small computers within a single integrated system
Contains a processor, core memory and programmable input and output capability
A PIC chip is a common form of microcontroller
• peripheral interface controller
• uses flash memory
programs in a variety of computer languages or in software that allows use of flowcharts for programming

Question 5

Flash memory

Answer 5

Can easily be overridden and reprogrammed

Question 6

Microcontrollers

Answer 6

Cheap
Little power usage
Small

Question 7

Example products that contain microcontrollers

Answer 7

Car engine control systems
Remote controls
Washing machines
Mobile phones
Uses:
Counters
Timers
Decision making

Question 8

Products using LDRs

Answer 8

Streetlights
Safety clothing
Garden lights
Phone sensors
Cars

Question 9

Products using thermistors

Answer 9

Thermostats
Kettles
Hot water tanks
Dishwashers