Difference between revisions of "Light-emitting diode"
Jump to navigation
Jump to search
(link to other Open Circuits pages) |
(wiki that discuss "throwies") |
||
| Line 15: | Line 15: | ||
[[POV display]] | [[POV display]] | ||
| + | |||
| + | == throwies == | ||
| + | |||
| + | Several other wiki discuss how to turn LEDs into "throwies": | ||
| + | |||
| + | * [http://c2.com/cybords/wiki.cgi?ThrowieTalkie Cybords wiki: Throwie Talkie]: A Talkie is a Throwie that has been hacked to blink graffiti messages in Morse code. | ||
| + | * [http://wiki.tagrecord.com/Throwies TagRecord.com Wiki: Led throwies] | ||
| + | * [http://wiki.feedle.net/index.php?title=Throwies the mayowiki: Throwies] | ||
== sensor == | == sensor == | ||
Revision as of 19:57, 21 May 2009
A light emitting diode is the most popular kind of optoelectronics.
To make the LED light up, you need a power supply (any voltage) and a resistor.
The resistance required is as follows: R = (U_power - U_led) / I_max
Example: a LED with voltage drop of Uled=1.2V and a max current of I_max=0,020A (20mA) to be powered by a 5V DC source needs:
R = (5-1.2)/.02 = 190 ohm
You then connect a 190 ohm resistance in series with the LED to make it work.
Contents
POV
throwies
Several other wiki discuss how to turn LEDs into "throwies":
- Cybords wiki: Throwie Talkie: A Talkie is a Throwie that has been hacked to blink graffiti messages in Morse code.
- TagRecord.com Wiki: Led throwies
- the mayowiki: Throwies
sensor
A few people use LEDs in an unusual way: as sensors.
further reading
LEDs used normally: to emit light:
http://en.wikipedia.org/wiki/LED
LEDs used "in reverse": as light sensors:
