I've tried several times to wire LEDs into my car, I just can't get the voltage right. I've bought LEDs from lsdiodes and used the voltage counter to try decide on what strength of resistors I need for my LEDs. I'm running a power wire from my battery to a fuse then into a switch, it's three lead. Then running my wires to my LEDs off that one switch in a parallel circuit. I have 12 in my dash each on a set of four LEDs in a Parallel circuit with resistor. Can someone tell me what I'm doing wrong? I think I need to buy new LEDs because I think mine might be blown
but I don't know? I'm using the 8mm Green 7500mcd LED, and I'm trying to run them at 7200mcd or 3.6 volts a piece. Thanks in advance.
Don't you run them in series instead of parallel?
I think that is right. Correct me if i am wrong guys
First, double check your wiring and switch wiring. I run my LEDs in parallel to something else (like interior lights, neons, ect [check profile]) and I have no problem. A simple way to check if your LEDs are good is with a multimeter. Switch it to the diode symbol, and hook up the leads to the LED. If it is connected correctly to the meter, it will light up, but it will be dull, but it will still work. Check that.
As for the resistors, put a 500 ohm in series with the LEDs, then wire the LEDs in parallel, like so
o< is the LED
/ = switch
'|'|'|'|'|'| ---/----/\/\/\/\/\-----o<---|
| 500 ohms | |
| o< |
|---------------------------|------|
add more LEDs if necessary, but that is the scematic
E-mail me if you need to: atroxaranea@hotmail.com
Also, where are you located? I am in NJ and if you are nearby you could come over and I could wire them for you.
Sam
Ban low-performance cars, not high-performance ones.
I got some help from Sam but I'm still lost. If im using the 8mm Green 7500mcd LED, and I'm trying to run them at 7200mcd or 3.6 volts a piece what strength of resistor would I need to run four in parallel then ground them?
If you order LEDs from www.oznium.com, they can include the resistors with your order. The LEDs are like 30 cents and the resistors are 5. I've had great results with their products.
one thing to remember, is that when you calculate you r resistor, take in consideration that youre not running 12V........ when i do my calcs, i use 13.5 or 13.7.......
you might not be resting enough voltage.......
i'm trying to find the calculator that i use, but i guess it's on my work's computer
i'll try to get it to you
wait for it... wait for it... NOW GO!! ---> '02 LS Sport <---
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did you figure it out?
wait for it... wait for it... NOW GO!! ---> '02 LS Sport <---
Yahoo IM : buzz122 AIM : buzz122cav
Clicky
Here's a good calc to use for LED voltage. Use 13.8v as the source voltage and the specs from the data sheet for the rest of the entries.
I know, a little late...
Ok so i just used your clac. Kardain and this is what I came up with
This is the link to the Led I bought:
http://www.lsdiodes.com/shop/index.php?main_page=product_info&cPath=7&products_id=64main_page=product_info&cPath=7&products_id=64
Using a 8mm Green Led that runs at 3.6 volts and a Ma of 30 putting 3 in a series circuit.
Solution 0: 3 x 1 array uses 3 LEDs exactly
+13.8V R = 100 ohms
The wizard says: In solution 0:
each 100 ohm resistor dissipates 90 mW
the wizard thinks 1/4W resistors are fine for your application
together, all resistors dissipate 90 mW
together, the diodes dissipate 324 mW
total power dissipated by the array is 414 mW
the array draws current of 30 mA from the source.
In the diagram it gave me it showed the Resistor after the Leds, is that right? I thought if they were in series that it went: Batt---Switch---Res.---(+)LED(-)---(+)LED(-)---(+)LED(-)---Ground?
Ok and if that Calc is right all I need is one 100ohms resistor before my LEDS right, right?
Sorry If I making this seem really really difficult but, I'm just lost on the whole resistor thing even with ohms law? Thanks again.
Landon Womack wrote:
In the diagram it gave me it showed the Resistor after the Leds, is that right? I thought if they were in series that it went: Batt---Switch---Res.---(+)LED(-)---(+)LED(-)---(+)LED(-)---Ground?
The most efficient way is to place it before the LED's. Your diagram is correct and will pose the least amount of problems.
Landon Womack wrote:
Ok and if that Calc is right all I need is one 100ohms resistor before my LEDS right, right?
Sorry If I making this seem really really difficult but, I'm just lost on the whole resistor thing even with ohms law? Thanks again.
I verified the data entry with another calc that I use frequently:
Clicky
and it is also saying 100 ohm resistors based on the data entered.
So just place the resistor inline before the LED's and enjoy.
Ok well I got my three LEDs in and I'm going to wire them in, if they work I only have to buy like 30 more for my interior. It might be a couple of weeks before the rest of my LEDs come in and I have time to put them in but, I'll post some pics of a finished install, hopefully without anymore problems. Thanks for all the help guys!!
