Transcript Sensors PPTx - Chesham Grammar School Moodle

STARTER
What is the function of each of the electronic
products shown below and what do they all have
in common?
Plant Water
Detector
Electronic Drum
They all detect
something and
then respond
But how?
Blood Glucose
Level Detector
Solar Garden
Light
Electronic
Thermometer
WHAT SENSOR?
What is the sensor used in each of these electronic products and
what does each detect?
LDR
A Light Dependent Resistor is a type of resistor
whose resistance changes according to light.
Bright Light – low resistance (≈1KΩ)
Darkness – high resistance (≈1MΩ)
WHAT SENSOR?
Thermistor
A thermistor is a type of resistor whose resistance
changes according to temperature.
High temperature – low resistance (≈70Ω)
Low temperature – high resistance (≈1KΩ)
WHAT SENSOR?
Moisture Sensor
A Moisture Sensor is a type of resistor whose
resistance changes according to moisture.
Wet – low resistance
Dry – high resistance
They tend to be made from two copper or brass rods
or as a PCB
WHAT SENSOR?
Piezo Electric Transducer
A Piezo Electric Transducer works in a very different way
to the other sensors you have learnt about today in that it
produces a voltage in response to any vibration
WHAT SENSOR?
Biosensor
HOMEWORK: Topic 23