Laptop/electronic power supplies for LED lights

has this question already been covered somewhere here?


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PicklesRus

Well-Known Member
I noticed today a couple Hewitt Packard printer power supplies that read 32v output and I am wondering if it would be a good idea to run Cree COBs with it. Would buying meanwell drivers be worth it if I already have these? Can someone help me understand the downfall to using these compared to a meanwell LED driver?

Input: 100-240v 1300ma
Output: +32v 1560ma

I also have a bunch of other 12v and 19.4v supplies - it would be great if I could use this stuff for LEDs.
 

Abiqua

Well-Known Member
Constant Voltage most likely and Not constant current, which is what most diodes require...

They can be used to power a buck / boost driver that will convert to DC constant current [Recom, Meanwell for example].

Also 32 volts is still too little for a vF of most Cree COB's especially 3070/3590's.......so you would need a boost anyway :peace:
 

PicklesRus

Well-Known Member
Constant Voltage most likely and Not constant current, which is what most diodes require...

They can be used to power a buck / boost driver that will convert to DC constant current [Recom, Meanwell for example].

Also 32 volts is still too little for a vF of most Cree COB's especially 3070/3590's.......so you would need a boost anyway :peace:
Thats enough of an answer for me - thanks!
 

kmog33

Well-Known Member
Constant Voltage most likely and Not constant current, which is what most diodes require...

They can be used to power a buck / boost driver that will convert to DC constant current [Recom, Meanwell for example].

Also 32 volts is still too little for a vF of most Cree COB's especially 3070/3590's.......so you would need a boost anyway :peace:
Vero 18s run under 30v.


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kmog33

Well-Known Member
You could run 2 in parallel on that driver possibly. Would get them down to nominal output current.


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Abiqua

Well-Known Member
Vero 18s run under 30v.


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Yes....but he asked about Cree....and I only mentioned the 3070's/3590's in terms of vF, there is probably lower series of Cree's 2530's? that will run 32v or less...

Besides all that...its Constant Voltage.....so its moot anyway.
 

kmog33

Well-Known Member
Yes....but he asked about Cree....and I only mentioned the 3070's/3590's in terms of vF, there is probably lower series of Cree's 2530's? that will run 32v or less...
I think you're right but I also think the 2530s still run at higher voltage than 30 and the vero 29s also run too high a voltage for the driver specs. I just know the 18 veros are 28-30v and run at 850ma nominal. So if you ran that driver with the cobs in parallel it would end up running 2 Vero 18s at just under their nominal current which would give you their best efficiency as the veros like to be driven higher than the crees.


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littlejacob

Well-Known Member
Bonjour
I also have an old switching power adaptor...60w
Input 100-240v~50/60Hz 1.5Amax
Output 12.0V 5A
Is there any chance I could use that for any cob or monos? V13...cxa 2530?
Have a nice day !
 

PicklesRus

Well-Known Member
Bonjour
I also have an old switching power adaptor...60w
Input 100-240v~50/60Hz 1.5Amax
Output 12.0V 5A
Is there any chance I could use that for any cob or monos? V13...cxa 2530?
Have a nice day !
12V xA adapters are everywhere, it would be great if they were good at driving LEDs.

I've been following a CXB3070 + Meanwell HLG-185H-1400 build thread and think I'll go that direction.
I guess I am now more curious about using these alternate PS for cheap Chinese LEDs I was buying off ebay.
I found this guy who used a laptop adapter and boost driver like Abiquia mentioned to power an LED.
I think it would be OK to experiment with cheap LEDs with laptop adapters but definitely will go with a good driver for good COBs.
 

littlejacob

Well-Known Member
Bonjour
Good idea for the cxb...but why not the
3590?...3500ºk cd like mine...those are amazing!
I don't want this big heat factory in the middle of my room anymore
CU
 

bassman999

Well-Known Member
I noticed today a couple Hewitt Packard printer power supplies that read 32v output and I am wondering if it would be a good idea to run Cree COBs with it. Would buying meanwell drivers be worth it if I already have these? Can someone help me understand the downfall to using these compared to a meanwell LED driver?

Input: 100-240v 1300ma
Output: +32v 1560m
I also have a bunch of other 12v and 19.4v supplies - it would be great if I could use this stuff for LEDs.
I bought some generic chinese square cobs to test, and powered it with a 32V power supply like you mentioned. It worked, but the voltage and current changed as soon as the load was on it to 30V roughly.
I cant say how reliable it would be, and I wouldnt run those cobs for anything but shop light or security light

EDIT I am looking at my power supplies, and I have a 12V a 24V, and a 32V.
I cant say for sure what I powered those generic cobs with.
It drop voltage by 2 V I think though.
 

littlejacob

Well-Known Member
Bonjour
Same for me I was asking cause a friend need a light who do not pull much heat for his Gecko!
And since I have this and a 80mm round hs with Cooper core that I found in a dump yard!
CU
 

DIY-HP-LED

Well-Known Member
I use an X box PSU (12V and lots of amps) that I picked up at a goodwill store for $5 to power an LED side light. I use 4 X current limited buck converters to power 4 X cheap 10 W LEDs in parallel in four arrays for a total of 16 10 W LEDs on a 42"L 2" X 1" piece of rectangular aluminum tube. I limit the current to 675ma per LED ( X4 in parallel) using jumpers on the buck converter set to 2.7A. I was running the converters at 3A but found it ran a bit too hot for my liking.

Trying to up convert from 12V to 36 or 39 volts is way too inefficient, better to use 12V to run cheap 10 watt chips at 10.5V or series strings of 3 X 3W LEDs using a current limiting down converter or any adjustable DC-DC down converter with enough amps to handle what you want.
 

alesh

Well-Known Member
Vero 18s run under 30v.


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You could run 2 in parallel on that driver possibly. Would get them down to nominal output current.


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That's an ill advice, you shouldn't spread it.
It would overload both the supply and Veros. Depending on the supply's protections, it could end up badly.
 
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frica

Well-Known Member
Wouldn't try experimenting because constant voltage isn't ideal for LED.

Besides, the Vero 18 does not run at 32V.
It runs at 31.6V at 2100mA, so with a 32V constant voltage power supply it would try to pull more than 2100mA which the supply can't handle.

http://www.bridgelux.com/sites/default/files/resource_media/DS31 Vero 13 Array Data Sheet Rev J 20150908.pdf
Also I see on the Vero datasheet that as the temp rises (25-85 degrees celcius) the voltage is less at the same current but since a laptop power supply is constant voltage the voltage can't drop and the current will probably rise.

The Vero 13 does run at around 32V and you could probably put 2 in parallel, but with 3 you will certainly be at risk of frying either the chips, the supply or both when the COBs start getting hot.
1 Vero 13 should be safe for your 32V laptop power supply but that's just a 15 watt light and I don't think it's really worth the trouble. And you would barely safe any money at all with it because a 500mA 20 watt LED driver doesn't cost much.
But I wouldn't risk it since those supplies aren't made for LEDs.
And a Vero 13 isn't ideal for growlights either way when you can have the 18 and 29.

And you should take that last paragraph with a grain of salt because I haven't tested it myself.
Can't guarantee even 1 Vero 13 would be safe.
Constant voltage supplies give all kinds of complexities to LEDs.
 
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