Sensors_Part1 Flashcards
Contact sensor
measured object comes into mechanical contact with the sensor
(e.g. limit switch)
Non-contact sensor
no physical contact between the sensor and object
(e.g. IR sensor)
Analog Sensors – Flex (Bent) Sensors
Type of electronic sensor that measures the degree of bending or flexing of a material.
- directly proportional
Advantages of Flex (Bent) Sensors
easily integrated into wearable devices (such as fitness trackers, to measure the movement of the body)
Light Dependent Resistor (LDR)
Type of resistor that changes its resistance based on the intensity of light that falls on its surface.
- inversely proportional to the intensity of light (the resistance decreases as the intensity of light increases)
Advantages of LDR
low-cost & simple devices
Resistive Temperature Detector (RTD)
changes its resistivity with temperature
- Resistance of most metals increases over a limited temperature range, in a reasonably linear way with temperature.
Advantages of RTD
- Stable, high accuracy, and repeatable
- Less susceptible to electrical noise and interference than other types of temperature sensors (such as thermocouples)
What is Sensor?
a device that converts a physical phenomenon (stimulus) into an electrical signal
What is Transducer?
a device that usually converts one type of energy to another.
(Eg. Most transducers are either sensors or actuators)
Input devices
Temperature (Analog)
Push Button (Digital)
Output Devices
LED (Digital)
Buzzer (Digital)
Digital Signals (Square Wave)
discrete signals that represent information in binary code, consisting of 0s and 1s.
Applications of Digital Signals
Used in modern communication systems
(Eg. the internet, cellular networks, and satellite communications)
Analog Signals (Sine Wave)
Analog signals are continuous signals that vary in amplitude and frequency over time.
