3 Watt LED array with 1 watt resistors; Power Supply questions

mcgyvr

Joined Oct 15, 2009
5,394
Probably something like
A few 50 or 100W LEDs mounted on fan cooled Duron heatsinks..
Meanwell LPF drivers (1 per 100W LED)
No idea how much power this "treatment" really needs though.

The short 20min duty cycle "may" be your saving grace as far as heat goes..
BUT I base my time calcs off having a heatsink and the time it takes that to reach thermal stability (between 30 minutes to 1 hour).. I'd expect the LEDs like you have it will get up to temp in fairly quickly (5 minutes or less)

My wife suffers from a "similar" disease (in the winter months only as she gets plenty of sun in the summer)..
When/if it bothers her she either just hits the tanning beds every few weeks or we just go to the beach house in Florida and hang at the pool.. :)


BTW.. Make damn sure your victims NEVER look at the LEDs like that.. Permanent eye damage can happen VERY quickly with high power LEDs.. I'd suggest welding glasses.
 

MCU88

Joined Mar 12, 2015
358
BTW.. Make damn sure your victims NEVER look at the LEDs like that.. Permanent eye damage can happen VERY quickly with high power
Seems like an alternative punishment to being smacked around the head with a bloody brick or an baseball bat IF YOU ARE.
 

BobTPH

Joined Jun 5, 2013
8,967
I think the only thing that has saved it is the fact that you are getting about 1/4 W for each of your 3W LEDs the way you are driving them.

Bob
 

mcgyvr

Joined Oct 15, 2009
5,394
I think the only thing that has saved it is the fact that you are getting about 1/4 W for each of your 3W LEDs the way you are driving them.

Bob
Yeah hes over 1W on each of those.. Heat WILL be generated..
It will double as the heat source for an Indian sweat lodge if the skin thing doesn't work out :)
 

Sensacell

Joined Jun 19, 2012
3,449
The main problem is clearly going to be thermal overheat of the LED's- the only thing I can suggest is to run this rig at a significantly reduced current and monitor the temperature to see how hard you can push it - consult the manufacturers data sheet for max device temps.

Thermal management of high power LED's is always an important consideration, one never runs a high power LED at rated power without a heat sink- POOF!
 
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