Led light setup. need help, will this work?

Thread Starter


Joined Apr 29, 2017
hey guys!

first of im new to the forum, hope i posted in the right place.
so, ive decided to make an led light setup, but i have no basic knowledge of electronics and/or electricity in general, so after alot of research i came up with this setup, and i would like to know if this will work and if it does, if its a safe setup.

for main power source i have modified an old pc power suply. on the 12v rail its rated at 11A wich would give me a total of 12v*11a = 132W, lets say 100-110W tops to be on the safe side.

with this psu idd like to power the following LEDs:
1) 1x 50W cob led @ 30-36v / 1.5A (with active cooling) + driven by a dc boost converter from ebay with the following speccs:

Input voltage: DC 10V-32V.
Output voltage: DC12V-35V(adjustable).
Output current: 10A (MAX).
Input current :16A (MAX) (more than 10A please strengthen heatsink).
Output power: natural cooling 100W (MAX), strengthening cooling 150W (MAX) real power.
Conversion efficiency: 94% (when Input 19V 2.5A Output 16V, Reference).
Output ripple: 2% (MAX).

50w led -> boost converter -> 12v dc power suply (pc psu)-> wall plug
2) 10x3w led 10 in series. 1 led is rated 3.2V-3.4V 560mA-700mA, so i figured 10 would be 32/43v @ 0,7mA + 30W constant current driver also from ebay with the follosing speccs:

Input Voltage: DC9-24V
Output Voltage: DC30-38V

10x3w in series -> constant current driver -> 12v dc power suply (pc psu) -. wall plug


from what i have calculated i figured the 50W led would draw from the psu around 54W and the 10x3w leds would draw roughly 31W with a total power draw from the 12v power suply of 85W (12v*7A)

so my questions are:
1) is the 50w setup and the 10x3w setup ok? will it run safelly?
2) after desoldering the extra wires from the psu, i have 6 yellow (12v) wires left. i thought of using 2 wires (2yellow +2black) to power the 50W led, 2 wires (2yellow +2black)to power the 10x3w leds, 1 (yellow + black) wire to power coolers, and leave 1 wire aside. will this work? considering its a YES on question one
ive seen people on youtube using psu-s as 12v power suplies connecting all yeallow wires togheter so i figured it would be safer to use 2 wires to power each led setup.

thank you very much in advance, hope to hear your opinions!
Last edited by a moderator:


Joined Jun 22, 2012
Connect all the Yellows together and connect all the Blacks together, that way your psu can supply the maximum output it needs, without the cables getting warm., then fuse each load accordingly for safety.

Just out of curiosity, will the 3V leds not run on the 3.3V Orange rails.


Joined Oct 15, 2009
Does your boost converter for the 50W LED have current limiting (constant current module too?)

Personally I would use a regular constant voltage 48V DC power supply and 2 meanwell LDD LED drivers..
Specifically a LDD-1500HW for the 50W and a LDD-700HW for the 3W leds in series and avoid all the boost converters,etc..
Just cleaner/better/dimmable, etc... IMO...

Thread Starter


Joined Apr 29, 2017
thank you for the answers! i think what ill do is get a boost converter with adjustable voltage and current, get 3x30W LEDs and give up on the 3v leds