How to reduce led driver current?

[rajivzee]

I have meanwell lpc 35-700 led driver which outputs at 700ma and i want to run led string but at lower current.
Let say 500ma or 600ma, How can i achieve this?

[sushant]

I have meanwell lpc 35-700 led driver which outputs at 700ma and i want to run led string but at lower current.
Let say 500ma or 600ma, How can i achieve this?

why do you want this??

[rajivzee]

The max current rating of my led's is 700ma and I've read that to have better led life it should be run at around 80%

[saikumar]

How about 350mA?

[rajivzee]

How about 350mA?

That will work

[saikumar]

great, just add all your LEDs in two parallel strings. Automatically you ll get 350mA through a single LED.

All the best!

[rajivzee]

great, just add all your LEDs in two parallel strings. Automatically you ll get 350mA through a single LED.

All the best!

Thanks man it is so simple.

[sushant]

The max current rating of my led's is 700ma and I've read that to have better led life it should be run at around 80%

I guess that it's not maximum current rating, its optimal current rating. And at this current the performance and efficiency of the device is maximum. You just have to control the heat produced. Maximum current that a 3W led rated at 700mA is around 1A or 1000 mA.

[sushant]

great, just add all your LEDs in two parallel strings. Automatically you ll get 350mA through single LED.

All the best!

Thanks man it is so simple.

But in this case you roughly get as many lumens as a 1w led. If you really wanted to run it at 80% should have gone for a dimmable driver

[saikumar]

great, just add all your LEDs in two parallel strings. Automatically you ll get 350mA through single LED.

All the best!

Thanks man it is so simple.

But in this case you roughly get as many lumens as a 1w led. If you really wanted to run it at 80% should have gone for a dimmable driver

agree big time!

The max current rating of my led's is 700ma and I've read that to have better led life it should be run at around 80%

I guess that it's not maximum current rating, its optimal current rating. And at this current the performance and efficiency of the device is maximum. You just have to control the heat produced. Maximum current that a 3W led rated at 700mA is around 1A or 1000 mA.

you got a few wrong assumptions mate.

1. ~750mA is the device maximum indeed, may be a +50mA more.
2. All LEDs have efficiency graphs peaking at low currents, so lower the current more efficiently they run.
3. Maximum current rating of CREE 3W can be 1A as they have low forward voltage. Edison etc have 3.7-4V, where asCREE maxes out at 3.2V for such currents.
4. Running a 3W at 350mA is more efficient than running a 1W at 350mA, reason as above. Meaning more lumens at same power and safer.