COB LED and fan all off one power supply?

[mashman]

Hello all you lot,
new here and asking for your expertise and knowledge.
basically I have some cob leds and power supplies which run fine, the only problem is they run quite hot and so have to be stuck on a heatsink but still overheat quite quickly.
Is it not possible to run a 12v fan off the same power supply ? even running on 6v or 9v or something i was looking at l780xxxx voltage regulators but I dont know if this whole idea would just overload the power supply which I suppose is designed to just run the led. and if so why doesnt someone make a psu to run a fan too as they get too hot seems crazy to me!
any ideas, thoughts? I dont know a great deal about electronics.
Input: 85-260V AC
Output: DC 18-36V
Power: 6W-10W
never mentions the current output for these tho
the led specs are:Voltage: DC 32-34V
Current: 350mA
Power: 10W

any help much would be much appreciated,
thanks
Matt

 

[DIWdiver]

It sounds like you have a supply that's specifically designed to run the LEDs and nothing else. If so, then any power you draw off the supply for something else would reduce the power that goes to the LEDs.

The reason they don't design a fan supply into the LED supply is that many people don't want fans running anyway. Besides, it would have to be a completely separate supply, just packaged together, so there's very little savings, and it drives up the cost of the supply, making it harder to sell to a general market.

What you really want is a little wall-mount plug-in supply of the same voltage as your fan.

 

[SemiMan]

It sounds like you have a supply that's specifically designed to run the LEDs and nothing else. If so, then any power you draw off the supply for something else would reduce the power that goes to the LEDs.

The reason they don't design a fan supply into the LED supply is that many people don't want fans running anyway. Besides, it would have to be a completely separate supply, just packaged together, so there's very little savings, and it drives up the cost of the supply, making it harder to sell to a general market.

What you really want is a little wall-mount plug-in supply of the same voltage as your fan.

Sorry DIWdiver, but that is not a suitable response.

That would in most cases just be an extra tap off an output transformer and even if another small circuit it may only add $1-2 to a driver resale as most fans would be small. There are drivers out there with auxiliary outputs for sensors, fans and the like. Nuventix drive was a target as well.

 

[JohnR66]

I'd avoid a fan if possible and use a properly sized heat sink. LEDs from any good manufacturer will provide lumen maintenance data at a given temperature to help you size the heat sink.

 

[DIWdiver]

Sorry DIWdiver, but that is not a suitable response.

That would in most cases just be an extra tap off an output transformer and even if another small circuit it may only add $1-2 to a driver resale as most fans would be small. There are drivers out there with auxiliary outputs for sensors, fans and the like. Nuventix drive was a target as well.

I stand corrected. Are those drives cost competitive with "plain vanilla" ones (meaning slightly higher to pay for the additional circuitry)?

 

[Toaster79]

What's your application? There are fans that run of mains but can be quiet bulky.