# Simple LED wiring help

Discussion in 'General Electronics Chat' started by guitarguy89, Sep 14, 2014.

1. ### guitarguy89 Thread Starter New Member

Sep 14, 2014
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Alright so,
I've done a few small wiring projects before but I can't really figure out what's going on.
I just bought my girlfriends son one of those 12V ride on cars for kids. It works great and he loves it. But I got the wise idea to ad lights to it. So I drilled out the backs of the headlights and side mirrors, as well as the brake light in the spoiler. Altogether I'm running 6 5mm red led's and 2 jumbo white ones. (I believe they are 10mm) so when I hook up the power to the 12v battery, nothing.
Do I just need more power?
I have all of the positives wired together and all the negatives wired together

2. ### Lee697 New Member

Aug 31, 2014
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Are they LED bulbs/lights, or plain component LEDs?? If they are bare component LEDs they are probably dead (after a very brief flash of light!) if you didn't use an appropriate current limiting resistor...

3. ### mcgyvr AAC Fanatic!

Oct 15, 2009
5,063
1,099
LEDs need to be fed a constant current (resistor or LED driver) or they will just burn up and the dc output voltage needs to be greater than the sum of the forward voltages of all LEDs in the series string.

You probably need to split your LEDs up into 2 series strings with a current limiting resistor on each string..

Tons of LED calculators out there to calculate the resistor value for you..

4. ### Lee697 New Member

Aug 31, 2014
26
0
If you solder a resistor to each, you can parallel them in a similar way you tried....
Standard LEDs on 12V, I'd use around 500 Ohm resistor, for approx 20mA current through the LED....

5. ### ian field AAC Fanatic!

Oct 27, 2012
5,473
973
You can also get LEDs with a built in current limiting chip, needs 1 per series chain and needs checking for same current as the others in the chain - especially the jumbo LEDs.