Alternative Powering idea, will it work?

nomofatum

Well-Known Member

• Jan 14, 2016

• #1

Power is supplied from 36v switching power supply, lets assume a 400w/11a.
Each COB is attached in parallel, but with it's own constant current circuit (currently thinking based on LM317)

http://www.bristolwatch.com/ccs/LM317.htm

Will voltage float around like a MW CC Driver with a circuit like this?
If not, will the COB be as happy/efficient at 36v 1000ma for CXB3070 or 1500ma for CXB3590, vs running at the same ma on a MW CC Driver?

 

Last edited: Jan 14, 2016

Abiqua

Well-Known Member

• Jan 14, 2016

• #2

looks like the T0-220 max is 1a and the To-92 is 500mA

 

nomofatum

Well-Known Member

• Jan 14, 2016

• #3

Abiqua said:

looks like the T0-220 max is 1a and the To-92 is 500mA

Click to expand...

SOT-223 =1000ma
TO-263 or TO-220 or TO-3 = 1500ma

I don't know much about making electronics like this, so hoping someone with the expertise can help shore up or blow the idea out of the water.

Am I reading something wrong on the TO-220?
http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/CD00000455.pdf

 

Last edited: Jan 14, 2016

guod

Well-Known Member

• Jan 14, 2016

• #4

if you can live with the voltage loss and the additional Heat

 

nomofatum

Well-Known Member

• Jan 14, 2016

• #5

That is 9% loss total. It would be nice to cut that in half or less somehow. Any ideas on more efficient CC circuits?

The idea behind this is to be able to make a modular track-light type setup where a light can simply be clipped onto the 36v track and regulate it's own current. The LED unit would include the contact/track mount, a heatsink/fan, a IC to supply regulated power to the fan and LED, and of course the COB itself.

The IC would be mounted to the side of the LED heatsink.

 

guod

Well-Known Member

• Jan 14, 2016

• #6

the hard way......google "constant current mosfet op amp"
or
use Bucks ....
Meanwell LDD-H...LDH-45
Recom-Power RCD-48

btw. 36V is damn low for this idea....

 

nomofatum

Well-Known Member

• Jan 14, 2016

• #7

guod said:

the hard way......google "constant current mosfet op amp"
or
use Bucks ....
Meanwell LDD-H...LDH-45
Recom-Power RCD-48

btw. 36V is damn low for this idea....

Click to expand...

Would this guy work? http://www.ebay.com/itm/300925643943

After looking at the ones you mentioned I remembered I already have 2 of these from a project where I was going to make lights for my truck, not the highest quality maybe, but good enough to test with I think?