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Electronics => Beginners => Topic started by: robotic on September 26, 2017, 12:40:51 am

Title: LED Driver 900ma okay for 700ma LED?
Post by: robotic on September 26, 2017, 12:40:51 am
So I'm planning on getting a 700ma 3W LED runs at 3.8V.  I'm planning to buy a 21-38V 900ma (+-5%) LED driver.
Will this work if I want to run 9 LEDs.

Main question is can i get a 900ma driver for 700ma leds, I always assumed leds will draw as much current as needed. not sure the LEDs will draw more then needed and burn out.
Title: Re: LED Driver 900ma okay for 700ma LED?
Post by: sleemanj on September 26, 2017, 12:59:12 am
No.

LED are current controlled.  You feed 700mA leds  900mA and they will gladly eat themselves to death.
Title: Re: LED Driver 900ma okay for 700ma LED?
Post by: Alex Eisenhut on September 26, 2017, 01:09:17 am
Light Emitting Dog?
Title: Re: LED Driver 900ma okay for 700ma LED?
Post by: robotic on September 26, 2017, 01:23:12 am
So 600ma Driver would be better?  Just less light?
Title: Re: LED Driver 900ma okay for 700ma LED?
Post by: sleemanj on September 26, 2017, 01:31:14 am
Yes

You probably wouldn't even notice less light anyway, and it will be better for the LEDs, less current = less heat.
Title: Re: LED Driver 900ma okay for 700ma LED?
Post by: bjcuizon on September 26, 2017, 02:41:31 am
Quote from: Alex Eisenhut on September 26, 2017, 01:09:17 am
Light Emitting Dog?
If more than the usual, rated current is put into the led, then LED will stand for "Likelihood of Earlier Death". ;)
Title: Re: LED Driver 900ma okay for 700ma LED?
Post by: Brumby on September 26, 2017, 05:18:11 am
Quote from: robotic on September 26, 2017, 12:40:51 am
I always assumed leds will draw as much current as needed.

No.  LEDs will draw as much current as they can.

As said above, offering 700mA rated LEDs 900mA will guarantee their early demise.
Title: Re: LED Driver 900ma okay for 700ma LED?
Post by: robotic on September 26, 2017, 10:59:40 pm
Thanks.  I'll buy the 600ma driver =).