Circuit Devices Flashcards
What is a diode made from and used for?
Made from semiconductor material such as silicon
Used to regulate the potential difference in circuits
What does diode do with current?
Let’s it flow freely in one direction but not in the other
High resistance in the other direction
What does LED stand for?
Light emitting diode
When does an LED emit light?
When a current flows through it in the forward direction
Why are LED’s being used more as lighting?
They use a much smaller current than other forms of lighting
What do LED’s indicate?
The presence of current in a circuit so they’re often used in appliances (TV’s) to show they’re switched on
Give three other uses of LED’s?
Digital clocks
Traffic lights
Remote controls
What is an LDR?
A resistor that is dependent on the intensity of light
What happens in bright light?
The resistance falls
What happens in darkness?
Resistance is at its highest
What are LDR’s used for?
Automatic night lights
Outdoor lighting
Burglar detectors
What is a thermistor?
A temperature dependant resistor
What happens in hot conditions?
Résistance drops
What happens in cool conditions?
Resistance goes up
What are thermistors used for?
Temperature detectors
Car engine temperature sensors
Electronic thermostats
