help with circuit diagram

Thread Starter


Joined Jul 9, 2007
I'm currently working on a project, please keep in mind I have no exper nor knowledge in this field. I've been on a "crash course" for the past 4 hours and this is what i've come up with..... is what i want to create. A led circuit for my tail lamps on my car.

The circuit diagram listed only had 12 LEDS, but my setup has 30 LEDS.

LED spec that I will be using
Super brite LED

My questions about this parallel setup......

1. will resistor "R1" still be the same?
2. what are the values for "R2" and "R3"? (If i'm correct, r2+r3= brake current=brighter)
3. will transistors remain the same or different?
4. will i need anymore transistors because i'm adding 18 more LEDS?
5. Switches "sw1" and "sw2"....How would i hook this circuit up to my tail lamp? the tail lamp has 3 wires: RED(POWER), BLACK(GROUND),GREEN/WHITE(BRAKE)

It will look something like so

o o o o o o o o
o o o o o o o
o o o o o o o o
o o o o o o o

thanks in advance


Joined Apr 27, 2007
In your case, I would use equal series of LED's for this, since you are controlling the LEDs using the same transistor. Also, the design in which you are based is not very good.