3 ms·
That would be a solution, however flicker-free dimming for LEDs is not difficult. Linear regulator chips are cheap, but inefficient. Switch-mode power supplies
by Zak 9y ago
That would be a solution, however flicker-free dimming for LEDs is not difficult. Linear regulator chips are cheap, but inefficient. Switch-mode power supplies cost a little more. Both are mature technologies any electrical engineer should be familiar with.
- amelius 9y agoNow that you make me think a little deeper about it, it seems simple indeed. The exponential V/I curve of the LED makes I unstable for a given value of V, so all you need to do is have a feedback loop that controls I.
- monochromatic 9y agoLED 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.
- Zak 9y agoEfficiency 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.
- monochromatic 9y agoThat’s interesting, I thought there was an optimal range. Do you have a link with more info?
- Zak 9y agoWell, 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 http://budgetlightforum.com/node/51693