News for hackers. Stuff that matters.

A comment on Eye Strain from LED Backlighting in MacBook Pro (2008). Parent comment

Re:Eye Strain from LED Backlighting in MacBook Pro (2008) by monochromatic on Saturday January 06, 2018 @09:15PM (#16088697)
LED light output isn’t linear in power input though. PWM allows you to drive the LED in its most efficient regime no matter how much brightness you want.
[ Parent | on HN ]
Re:Eye Strain from LED Backlighting in MacBook Pro (2008) by Zak on Saturday January 06, 2018 @09:47PM (#16088811)
Efficiency tends to decrease with current. It is rarely more efficient to run higher current and PWM than to simply run lower current.

It is, however often easier in terms of circuit design.

[ Parent | on HN ]
Re:Eye Strain from LED Backlighting in MacBook Pro (2008) by monochromatic on Saturday January 06, 2018 @09:58PM (#16088849)
That’s interesting, I thought there was an optimal range. Do you have a link with more info?
[ Parent | on HN ]
Re:Eye Strain from LED Backlighting in MacBook Pro (2008) by Zak on Sunday January 07, 2018 @12:02AM (#16089290)
Well, I can offer an example. This is a test of an LED using a bench power supply. In this test, efficiency drops every time current is increased, without fail.

http://budgetlightforum.com/node/51693

[ Parent | on HN ]