Wiring Multiple LEDs
Author: Wayne Eggert
Date: 09/19/2009
Difficulty: Basic
Description
Now that we've covered wiring a simple led and how to hook that circuit up to a solderless breadboard, lets take a look at how to wire multiple LEDs to learn some additional things about electricity. We'll discover how wiring multiple LEDs in series is different from wiring the LEDs in parallel and how each affects the amount of current drained from the power source. You'll also quickly understand why old strands of Christmas lights with a loose bulb would cause the entire strand to go out.
Materials
(1) Solderless Breadboard (optional but makes it easier to experiment)
(3) 5mm LEDs (any color)
(3) 140ohm resistors (anything between 140ohm-400ohm should be fine)
(1) Battery Power Supply (I'm using a 6v supply via 4 AA batteries in a battery holder)
Series Verus Parallel
Electronic components can be wired in many configurations. Wiring in series and in parallel are very common and you'll likely use both when desigining circuits depending on the results you're looking for. You're limited only by the size of your power supply and the optimal operating voltages / amps of your components.
I always like relating something technical to objects in everyday life, so to illustrate the difference between Series versus Parallel we'll use a favorite kid's toy -- dominos! It won't be a very scientific view of series versus parallel, but it'll work.
Dominos in Series
Dominos are a great toy, I never learned how to play the game, but I sure loved setting them up in rows and watching them fall! Now, picture a single row of dominos that stretches miles and miles. What happens if at any point in the row, a domino block falls wrong? GAME OVER!! Well, a single row of dominos is like wiring up electrical components in series. If any of those components fail, it can affect any other electronic components connected "in series" with the failing componenet. This is why old Christmas light strands with a loose or bad bulb would cause the entire strand to go out. The power stops at the failed bulb and it creates an open circuit!
Dominos in Parallel
Now, if you liked dominos as much as I did when I was younger, you've probably seen the domino competitions on TV where HUGE domino displays are created that require weeks or even months to setup. It wouldn't be very exciting if when they spent all that time setting up the dominos if 10 seconds in the dominos stopped falling. So the individuals setting up the dominos often plan for issues to occur and create two or three or four paths for the dominos to fork off. This not only makes it even more exciting to watch, but helps when something goes wrong with one of the paths. Well, that's exactly how the newer Christmas light strands are wired. If one light bulb is loose, it might not light, but all of the other bulbs will still light cause they are wired on a different path.
Lets take a slightly more scientific look at wiring LEDs in series and parallel..
page1 page2 page3Comments:
| why is the resistor connected after the led |
| Posted 06/05/10 3:02AM by try.myx |
|
as in your circuit diagram in the wiring multple led , why is the resistor connected after the led . isnt it supposed to be in front. now im in doubt. From the way i think and understand the resistor is used to minimise the voltage. so that the led will not recieve excess of voltage from burning it. please clear me the doubt . thnx in advance |