Some other
components
Resistor
Light Emitting Diode (LED)
Light Dependent Resistor LDR)
| Symbol for a resistor |
|
The resistor reduces the current flowing in a circuit
A HIGH resistance causes a LOW current
Light Emitting Diode (LED)
| Symbol
for a Light
Emitting Diode |
 |
The LED usually has a resistor to limit the current joined in series with it
The current can only flow in one direction through an LED so it needs to be connected the correct way around.
|
|
Example
LED 1 is ON LED 2 is OFF |
Light Dependent Resistor (LDR)
| Symbol for a Light Dependent Resistor |
 |
The resistance of an LDR varies with the amount of light on it
An LDR has a HIGH resistance in the dark and a LOW resistance in the light
An LDR can be used in series with a relay to turn on and off other components. See RELAY
