How do I wire LED's directly to molex?

[kfs65]

I bought some 12v 3mm LED's to put in my CPU block and was wondering if I could wire 2 of them to the 12v and negative on my PSU's molex? I have a corsair RM850 if that helps.

[W-L]

5 minutes ago, kfs65 said:

I bought some 12v 3mm LED's to put in my CPU block and was wondering if I could wire 2 of them to the 12v and negative on my PSU's molex? I have a corsair RM850 if that helps.

You can wire the two LED's in series and use a dropper resistor to hook it up to 12V. You will want to go for a half watt resistor for this.

 

12V-(2 x 3.0V LED)= 6.0V

 

R=V/I

R=(6.0V/0.04A)= 150Ohm resistor required

 

 

-Moved to Modding Section- 

[kfs65]

7 minutes ago, W-L said:

You can wire the two LED's in series and use a dropper resistor to hook it up to 12V. You will want to go for a half watt resistor for this.

 

12V-(2 x 3.0V LED)= 6.0V

 

R=V/I

R=(6.0V/0.04A)= 150Ohm resistor required

 

 

-Moved to Modding Section- 

I don't really want to buy anything else, but I will if I have to. Is it even possible to hook just one LED directly to the molex? 

[W-L]

16 minutes ago, kfs65 said:

I don't really want to buy anything else, but I will if I have to. Is it even possible to hook just one LED directly to the molex? 

No the LED's will just fry, the must have current limiting with the resistor. if you want they make exactly what your looking for here:

http://www.xs-pc.com/accessories/3mm-twin-wired-led

[kfs65]

2 minutes ago, W-L said:

No the LED's will just fry, the must have current limiting with the resistor. if you want they make exactly what your looking for here:

http://www.xs-pc.com/accessories/3mm-twin-wired-led

Okay, I guess I'm buying some resistors then! Thanks for the help

[kfs65]

2 minutes ago, kfs65 said:

Okay, I guess I'm buying some resistors then! Thanks for the help

Btw each individual LED is rated for 12V, is the 150Ohm resistor still adequate?

[W-L]

2 minutes ago, kfs65 said:

Btw each individual LED is rated for 12V, is the 150Ohm resistor still adequate?

What LED's are you using regular 3mm LED's are usually rated for 3V nominal for most colors except red and a couple of others. 

[kfs65]

They might be 3V. The ebay listing has little to none information wise. http://www.ebay.com/itm/282200043377?_trksid=p2057872.m2749.l2649&var=581207318833&ssPageName=STRK%3AMEBIDX%3AIT

[kfs65]

Sorry about all this I'm a complete noob

[W-L]

8 minutes ago, kfs65 said:

Sorry about all this I'm a complete noob

Oh those already have a resistor an LED installed under the heatshrink portion near the LED you can directly wire those to 12V for full brightness without extra work. 

This diagram should be helpful when wiring:

Edited February 16, 2017 by W-L

[kfs65]

2 minutes ago, W-L said:

Oh those already have an LED installed under the heatshrink portion near the LED you can directly wire those to 12V for full brightness without extra work. 

This diagram should be helpful when wiring:

I see the resistor under the heatshrink now, thanks for pointing that out!

[BigDan1190]

Just put 2 more 3V LEDs in the loop, then you're sorted.