3 ms·
Using analog brightness control is nice because there is no flicker, and there is no stepping. But, with common potentiometers there is only a very narrow oper
by foobarian 5y ago
Using analog brightness control is nice because there is no flicker, and there is no stepping. But, with common potentiometers there is only a very narrow operating band due to how nonlinear the LEDS are, and it tends to be pretty touchy due to construction of the pot.
I would love to figure out how to make an arbitrary transfer function shape using a pot as input, and some combination of transistors/op-amps to keep the nice analog behavior.
- JKCalhoun 5y agoPerhaps a feedback loop then with a small photo-resistor situated beneath the LED (looking up between its legs?).
- sdfasf 5y agoFlicker sucks, but LEDs are much more efficient when driven hard. So PWM is much more energy efficient for a given luminosity. That being said, if you're not on battery power, we're talking negligible energy. So, put a current source in there and stop giving me a seizure with your flicker.
- MayeulC 5y agoWhat if you replace your potentiometer with a DAC plus a low-pass filter (a RC circuit)?
- tyingq 5y agoThat would be some sort of constant current power supply.