Upload
others
View
1
Download
0
Embed Size (px)
Citation preview
LEDs
ElectronicsLight Emitting Diodes (LEDs)
Terry Sturtevant
Wilfrid Laurier University
April 17, 2012
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
LEDs (Light Emitting Diodes)
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
anode (+) cathode (-)
The LED lights up when current flows from the anode to thecathode..
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
anode (+) cathode (-)
The LED lights up when current flows from the anode to thecathode..
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
You must use a resistor to limit the current.Without a resistor, the LED will probably be destroyed.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
You must use a resistor to limit the current.
Without a resistor, the LED will probably be destroyed.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
You must use a resistor to limit the current.Without a resistor, the LED will probably be destroyed.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
The resistor can go before or after the LED.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
The resistor can go before or after the LED.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
The resistor can go before or after the LED.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
If the LED is reversed, it won’t light up.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
If the LED is reversed, it won’t light up.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
If the LED is reversed, it won’t light up.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
Here are some different LEDs.
Note that even though they are different shapes and colours, theyall have one pin longer than the other.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
Here are some different LEDs.
Note that even though they are different shapes and colours, theyall have one pin longer than the other.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
Here are some different LEDs.
Note that even though they are different shapes and colours, theyall have one pin longer than the other.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
On a breadboard, an LED can be connected to a resistor like this.
The signal would connect at the top of the LED.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
On a breadboard, an LED can be connected to a resistor like this.
The signal would connect at the top of the LED.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
On a breadboard, an LED can be connected to a resistor like this.
The signal would connect at the top of the LED.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
Here it is completely connected.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
Here it is completely connected.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
As stated previously, the resistor can be before the LED as well.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
As stated previously, the resistor can be before the LED as well.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
Here’s an easy mistake to make.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
Here’s an easy mistake to make.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
Here’s an easy mistake to make.
This looks like it should work, but it doesn’t.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
Here’s an easy mistake to make.
This looks like it should work, but it doesn’t. Note that both pinsof the LED are in the same row, so no current goes throughit.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
It’s easier to see what’s going on from the side.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
It’s easier to see what’s going on from the side.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
It’s easier to see what’s going on from the side.
From this angle you can see that both pins of the LED are in thesame row.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
LEDs can also be used for active low signals.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
LEDs can also be used for active low signals.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
LEDs can also be used for active low signals.
Notice the signal is connected to ground to light the LED.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
The LED and resistor can be reversed, as always.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
The LED and resistor can be reversed, as always.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
The LED and resistor can be reversed, as always.
The signal is again connected to ground to light the LED.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
Here’s a summary.
The two on the left are connected for active low signals.The two on the right are connected for active high signals.Both possible arrangements of resistor and LED are shown ineach case.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
Here’s a summary.
The two on the left are connected for active low signals.The two on the right are connected for active high signals.Both possible arrangements of resistor and LED are shown ineach case.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
Here’s a summary.
The two on the left are connected for active low signals.
The two on the right are connected for active high signals.Both possible arrangements of resistor and LED are shown ineach case.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
Here’s a summary.
The two on the left are connected for active low signals.The two on the right are connected for active high signals.
Both possible arrangements of resistor and LED are shown ineach case.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)
LEDs
Here’s a summary.
The two on the left are connected for active low signals.The two on the right are connected for active high signals.Both possible arrangements of resistor and LED are shown ineach case.
Terry Sturtevant Electronics Light Emitting Diodes (LEDs)