Fun Fact on LED and Digital Signals

For those of you that are like me, pretty bad with technology, but strangley addicted to learning about it, you might be interested in this. LED’s are cool lights and some may have noticed their ability to dim, as some electronics dim leds to show they are low battery, or asleep. To get the LED’s to dim, one can do it two ways, I believe. The first is to regulate the voltage, I guess thats an analog solution because regulating the voltage would round out the curve of the wave. The second is to blink the LED at at different speeds or different duty cycles, a digital solution because the wave is either high or low (binary). This second solution is cool because the blinking tricks the human eye to see that the light is dim, not flickered on for shorter times. The led gets turned off and on really fast, defining the period, and the time the led is on vs off is defined as the duty cycle. Both are key to defining rates for leds that are bright, dim, or even visable. If the period is too large, or the duty cylce is too small, you may not see the led, or may see some flickering. Here are some pics I took from the logic analyzer that show the digital wave of an led that is pulsed to first be dim, then brighten, then dim. check it out:


Lastly I got to thinking about the nature of digital electronics. So first, please excuse my naiveness, I am pretty stupid with computer, but always am trying. My thought on digital electionics is that the reason it’s digital is because the controller can only output a 0 or 1. But beyond that, the reason the controller can only dish out 0’s and 1’s is becasue a transistor it a switch, either on or off. Beyond that I guess the transistor only has two states because electrons are either positive or negative, but I pretty bad with physics. Regardless of how much of this doesn’t make sense and might be false, I think I am getting somewhere on understanding the physical layer within computers. I hope this helps too, and please, let me know what is really going on and what I said was wrong if you know, I would be curious to get corrected!