Understanding Electronics www.
kitronik.
co.
uk LDR
www.
kitronik.
co.
uk Page 1 of 1
Kitronik Ltd – How an LDR works
An LDR is a component that has a resistance that
changes with the light intensity that falls upon it.
They
have a resistance that falls...
More
Understanding Electronics www.
kitronik.
co.
uk LDR
www.
kitronik.
co.
uk Page 1 of 1
Kitronik Ltd – How an LDR works
An LDR is a component that has a resistance that
changes with the light intensity that falls upon it.
They
have a resistance that falls with an increase in the
light intensity falling upon the device.
The resistance of an LDR may typically have
the following resistances.
Daylight =5000Ω
Dark =20,000,000Ω
You can therefore see that there is a large
variation between these figures.
If you
plotted this variation on a graph you would
get something similar to that shown by the
graph to the right.
Applications
There are many applications for Light Dependent Resistors.
These include:
Lighting switch
The most obvious application for an LDR is to automatically turn on a light at certain light level.
An example
of this could be a street light.
Camera shutter control
LDRs can be used to control the shutter speed on a camera.
The LDR would be used the measure the light
int
Less
