systems approach to design 1.4 (DON'T NEED FOR MOCK) Flashcards
function of input devices
allow systems to understand changes in the environment around them
examples of input devices
a sensor such as a light-dependent resistor (LDR) that senses light levels for street lamps to know when it is dark
thermistors that detect when it is too hot or cold in a room.
the order of a system diagram
input, process, output
e.g: a street lamp
input = light sensor
process= switch
output = light
name 4 different types of switches
rocker switch
microswitch
push-to-make switch
pressure pad switch
name the uses for switches
1.turning something on
2.when an object as reached as far as you want it to travel
3.you want to start something by pressing
4.want to know if something is closed
5.to stop a machine if a guard is open
what do input processors do
take a signal from the physical or ‘real world’ and turn it into an electronic signal
what is a microcontroller
A computer chip used instead of a CPU that contains a processor, memory and inputs/outputs
what is a push to break switch
a switch that breaks a circuit when pressed
what is a push to make switch
a switch that completes a circuit when pressed
what are sensors
devices that are used to detect changes
how does a thermistor work
resistance increases as temperature decreases
what are pressure sensors used in
security systems
what do process devices do
take the signal from the input stage of a system and act on it by changing it in some way
Advantages of using microcontrollers
`they can reduce the size of a circuit
they can be reprogrammed many times, allowing changes to be made without replacing actual components
They have pins for connecting several input and output devices, adding to flexibility
disadvantages of microcontrollers
more expensive
The language of the system must be learned and this adds to training costs
