# Led light setup. need help, will this work?

#### Trebor88

Joined Apr 29, 2017
4
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:
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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 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
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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
Current:1000mA

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

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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.

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#### Dodgydave

Joined Jun 22, 2012
9,848
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.

#### mcgyvr

Joined Oct 15, 2009
5,394
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...

#### Wendy

Joined Mar 24, 2008
22,205

#### LesJones

Joined Jan 8, 2017
2,837
Some of the step up converters on Ebay can be modified to behave as a constant source. This is a link to how I modified one for this purpose. It may be possible to modify the one you have bought in the same way.

Les.

#### Trebor88

Joined Apr 29, 2017
4
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

#### Mellisa_K

Joined Apr 2, 2017
359
Wendy that link is awesome. Great resource for ppl like me just starting electronics hobby

#### Wendy

Joined Mar 24, 2008
22,205
Itried,Itiswhy Iwrote it. Bonhames Hobby circuits link at the bottom of my Index is also one I would recommend.

Wendy's Index

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