On Sun, Jul 5, 2009 at 6:10 PM, Olin Lathrop wro= te: > I don't read OT. =A0I am surprised however as I thought he was farther al= ong > than this. > > Solarwind, look up something called Ohm's Law. =A0It defines the relation= ship > between voltage accross a device, the current thru it, and its resistance. > In this case you don't control the characteristics of the LED, so you only > get to chose one of current thru it or voltage accross it and it will pick > the other. =A0You can't therefore push 1mA thru a LED (or any other devic= e) > while at the same time applying 1000V accross it (unless that device happ= ens > to be a 1Mohm resistor). > > At 1mA thru it forwards, you'll get around 2 to 2.5 volts accross most > normal red or green LEDs, and it will light dimly but visible enough in a > typcial office setting. =A0At 1mA backwards the LED is being driven in a > unintended way so results will vary more widely. =A0You probably get 5-20V > before it no longer acts much like a diode and allows 1mA of reverse > current, but I haven't tried that so my guess could be off. > > Conversely when you apply 1000V in either direction, the LED will draw way > more than 1mA for a very short time before it makes a popping noise and > emits a small mushroom cloud. =A0What happens after that, including arcin= g and > possibly catching fire is too dependent on the particulars of the LED, > humidity, and random chance to guess. =A0Let's just say it would be > "spectacular". =A0Once. Thanks for the reply. Please note: if this is a map - . . . .. . .. . . . . . . . .. . . . .. . .. . .. . . .. .. .. .. . . How do you define "further"? A B which one's "further"? The point is - there is no "further" - you just learn different things at different points. Something may not be "further" than something else. -- = http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist