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Resistors & LEDS & Buttons oh My!
Brad Lee:
Are resistors reversible? Meaning are they like diodes that would limit current one way and not the other? Or can they be conencted either way
Also, are 220k 1/4watt the correct size to go between a +5v power supply and a 2.2v LED? Thats the number that keeps popping into my head from reading earlier posts but I can't find anything right now
PacManFan:
Resistors can be used either way, they do not act like diodes.
I think you need a resistor in the range of 1k - 3k . Anything beyond that will be too dim.
-PacManFan
radiator:
pretty sure a resistor can be mounted either way...
...not sure about the value for a 2.2v LED though (off the top of my head anyway)
try a search in google for a resistor calculator
Birdtales:
Here are two resistor calculators....
http://members.cox.net/brutal/Resistor/main.html
http://www.bit-tech.net/article/68/
seaner:
resistors will resist current flow in either direction.
To determine the size of resistor you require, you need to know how much current the LED draws.
current = Votage/Resistance
so if your led need 5mA, for example, 1K ohm would do the trick.