led question

[the_weber]

so if I have 4 leds (all run Forward Voltage (V) : 3.2 ~ 3.8) so If i run them all onto the same power and ground wire. I wont need any resistors as long as I run all for to the same power/ground wire? right?

[cherrington17]

yes. You will run them in series. power wire connected to the first led's power lead. The ground on the first connected to the power of the 2nd. Ground of the 2nd connected to the power on the 3rd and so on.

[the_weber]

what if i have a power and ground coming off of each one spliced into a power and ground?

[cherrington17]

then you are powering each with 12V and they are in a parallel setup. You'll need a resistor on each.

[the_weber]

all four lit up for about a half second and blew. did it your way by running in series (which is what i should have done to start). Will try to do 5 tomorow instead and see if that gives enough resistance. Burned my hand and its 1130 pm here so I'm done for the night. thanks for the quick answer

[the_weber]

so I used four and the 5th one didnt light up. because like .2 volts is getting to it by the time the other 4 get there power. but tomorow i will put htm all in and see how it looks. I made some for both cupholders and 2 for under the radio. Then I made 2 clusters for 4 to go in the foot wells. Cherrington did you dremel yours for the cupholders or leave them rounded?

[Lucalare]

You can only really run four in series, otherwise you're cutting the voltage too low on them (which you all ready figured out). For that fifth one get the proper resistor (if you got them from oznium it should tell you what ohms you need), and hook the 5th LED with resistor to a separate power line.

[the_weber]

why not just cut the voltage down? Idc if the 5th one lights up.

[cherrington17]

resistors are cheaper than leds. which is why Luca's method is better.

I dremeled them, so they had a flush appearance when I put epoxy in the hole to seal them from water/moisture.