DTE - system and approach to designing

What is an electronic system?

-a series of parts or components that control a task or activity

-system made up of input, process and output stages

What are subsystems?

events or tasks that happen within a system

What is an open-loop system?

- they do not make decisions based on feedback

-a system that does not respond to changing conditions

What are the steps in an open-loop system?

input →process→output

What is an example of an open-loop system?

-toaster

-input (timer set, bread)→process (heating element)→output (heater off, toast made)

What are closed-loop systems?

Feedback is used to make a decision

What is an example of a closed-loop system?

an air conditioner

What is the decision flowchart symbol?

a rhombus

What are the flow chart symbols?

What is the start/end flowchart symbol?

an oval

What is the input/output flowchart symbol?

parallelogram

What do arrows represent in flowcharts?

the flow of instructions

What is the process flowchart symbol?

a rectangle

What are input components?

System or devices triggered manually or automatically using switches or sensors

What are output components?

change electrical energy into light, sound, heat or movement

What are examples of output components?

-light emitting diode(LED)

-lamp

-buzzer

-speaker

-motor

What are digital signals?

-Information, such as sound, being transmitted digitally.

-The signal is converted into a code using two symbols- 0 (off) and 1 (on).

-These are transmitted as a series of pulses (short bursts of waves), which are decoded back into the original wave.

What are examples of digital signals?

signals used for:

-Wi-Fi

-Bluetooth

-digital audio (MP3)

-digital video (MP4)

-data transmitted within microcontrollers

What are the two types of signals in electronic systems?

analogue and digital

What are examples of analog signals?

TVs, VCRs, radios, & old telephones

What are analog signals?

-continuous signals that represent physical quantities, such as voltage, current, temperature, or pressure, as a continuous range of values

-they can be used to transmit data and continually vary in amplitude

What is the difference between analog and digital signals?

-analogue signals have an infinite range of values between the minimum and maximum points

-digital signals are either on or off and are usually represented by a 1 (on) or 0 (off)

What are examples of inputs conponents?

-LDR

-pressure sensor

-switch

-temperature sensor

Temperature sensor

-detects a temperature change.

-When the temperature increases, resistance decreases.

-used in household devices and appliances

Light-dependent resistor

-Detects changes in light levels.

-Resistance increases in darkness and decreases in light.

-used in streetlights or security lights.

pressure sensor

-detects changes in pressure in gases and liquids

-used to detect a leak in a fuel system, triggering a warning light if the pressure fails

What are integrated circuits?

-An electronic circuit formed on a small piece of semiconducting material, performing the same function as a larger circuit made from discrete components.

Also known as microchips

What are microcontrollers?

Programmable Integrated Circuits (microchips)

What are examples of process components?

-resistors

-microcontrollers

What are monostable devices?

-single short timers.

-They go on once, then stay off

What are monostable devices used for?

-They are used for timing how long events occur, such as an automatic door opening and shutting

-The length of the pulse can be varied by changing the delay time

-The single pulse produced is usually triggered by a switch or sensor

What are astable devices?

-circuits that constantly alternate between on and off

What are astable devices used for?

-flashing lights on tall buildings and aircrafts

-The stream of pulses produced is oscillating and constant

-One cycle is the time a single pulse takes to go from 0 (off) to 1 (on) back to 0

What are PICs?

they can be programmed to count up and down and can take over the roles of many traditional ICs