electronics Flashcards
what does a system contain
an input process and output
example of how a bicycle works using input process and output
input - turning of the cyclists legs
process - chain and sprockets
output - rear wheel which propels e bike forward
what are circuits made of
components which are joined together by wires
what are PCB’s
- printed circuit boards
- boards with thin copper tracks (instead of wires) connecting components in a circuit
why are PCBS used
to reduce the size and the manufacturing cost of electronic systems
what is a conductor
a material that allows electricity to flow through it
why is copper used for wire tracks
because it is ductile, malleable and a good conductor
what does voltage do
pushes current around a circuit
what do resistors do
they reduce the current in a circuit so that you don’t damage delicate components
what do input devices do
they receive an external signal which triggers a system to worn
what do switches do
they turn a circuit on and off
- closed switch allows current to flow through a circuit
examples of switches
- toggle switch- flick to one position to complete the circuit
- push switch - push down and hold to complete or break the circuit
- slide switch - slide to one side to complete the circuit
what do variable resistors do
they change the resistance of a circuit based on an external factor
what are thermistors
- resistors that detect changes in temperature
- in hot conditions, t
resistance falls, in cold, it increases - used in central heating systems which turn off when a room reaches a certain temperature
what are LDRs and their uses
- light sensors, detect changes in light levels
- in brighter light, resistance falls
- used in automatic night lights
what are pressure sensors and their used
- detect changes in pressure in a system
- depending on the type of pressure sensor, resistance can either increase or decrease as pressure increases
- often used in equipment where gases or liquids are monitored. in cars, they are used to detect if there’s a leak in the fuel system. a leak would cause pressure to fall and this would trigger a warning light to come on
what do process devices do
receive inputs and determine the output
what are IC’s and what do they do and their advantages
- Integrated circuits are tiny, self contained circuits with billions of components built in
- they help simplify electronic systems by reducing the number of separate components needed in a circuit
- meaning they are cheaper and smaller, also use much less power because of their size
what is a microcontroller
- a mini computer on a chip which has a processor, memory and one or more inputs and outputs
advantages of microcontrollers
- can do the job of multiple IC’s
- unlike other IC’s, most can be reprogrammed for a different use
disadvantages of microcontrollers
more expensive than IC’s
where is the program stored in a microcontroller
in the microcontrollers onboard memory
examples of microcontroller boards
Arduino boards and BBC micro:bit
ways to programme a microcontroller
- writing a series of commands using a programming language such as BASIC and scratch
- creating a flowchart telling the microcontroller exactly when to start, how to make decisions based on input signals, when to add a time delay to the process, what to output and when to stop operating
