P2 - Circuit Devices (4) Flashcards
What is an LDR?
A Light Dependent Resistor is a resistor that is dependent on the intensity of light.
What happens to the resistance of an LDR when there is bright light and darkness?
In bright light, the resistance decreases.
In darkness, the resistance is at its highest point.
What applications use LDR’s?
Automatic night lights, outdoor lighting and burglar detectors.
What does the resistance of a thermistor depend on?
The resistance of a thermistor depends on Temperature
What happens to the resistance of a thermistor in hot and cool conditions?
in hot conditions the resistance drops and in cool conditions the resistance goes up
What useful things do thermistors make?
They make temperature detectors - car engine temperature sensor and electronic thermostats
What can sensing circuits do?
They can be used to turn on or increase the power of components depending on the conditions that they are in.
Why will a fixed resistor and a fan have the same PD?
Because they are connected in parallel.
