Let's Make Robots!

LED Breadboard

Lights up three LED's
IMG_3934.JPG3.01 MB
IMG_3937.JPG1.43 MB

This is my version of the breadboard walkthrough by Jklug80. Thanks for the intructions jklug. Anyway, I decided to add two more LED's and I used 510ohm resistors instead of 330ohm simply because i couln't find 330ohm in my house. I used a breadboard i bought at my local radioshack which cost me $14.99. The LED's I utilized were ones that my dad had laying around. I took the wires out of a telephone cable and connected them to a 9v battery.the double-sided adhesive tape seen was just used to keep the wires attached so i could take the pictures. I know i have not made anything significant but this is my starting point into the realm of robotics. Hope you like!!

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My dad has tons of micro controllers laying around and soon i will update this page to show the LED's flashing...I also plan to add a switch.
Congrats, Congrats... First step, my friend. You searched out info, figured it out, did it and improved it. Perfect. Now, your next step is to get your first micro controller and get those suckers to blink! Before you know it, you will be building your own PCB's!
I found some 330 ohm res. and you're right, the LED's were a bit brighter but the difference is minimal. Thanks for the help.
All right thx
You're fine you wont blow the LEDs, but they could be brighter. Not a big deal but ALWAYS do a quick math check to make sure you dont blow your LEDs. It isnt a big deal with the single color LEDs, but the Tri Colors are $3 each at Radio Shack and still about 25-50 cents each off ebay when bought in bulk. It can get costly and annoying if soldered on perf board.

OK time to bust out the math:
Red LEDs have a voltage drop usually around 2-2.2V, and your average ø3/5/10mm LED has a max forward current of 20mA. The nominal source voltage is 9V, and since each LED is in series with a resistor, any voltage not used by the LED will drop across said resistor giving you a maximum resistor voltage drop of 9V-2V=7V.
The current flowing through the resistor is the same as the current flowing through the LED, and Ohm's law tells us that the resistor current I=V/R=7V/510Ω=13.73mA. Since 13.73mA is less than the maximum 20mA limit, the LEDs will be fine. You could make them a little brighter by decreasing the resistor value a bit, but they should still run reasonably well.

Lets see here... carry the 4, round to the nearest tenth... looks good. A+!
No i didn't...will it make a difference?
The only problem is the resistor. Did you use ohms law to account for using a 9 volt battery? :)