Dimming LEDs (part 3/3) – The overlooked boundaries

In the last PWM discussion, we devised how is composed the average current, specially when the PWM frequency is faster than it should be, making the period duration comparable with the rise and fall slopes duration of the current. The results were packed up in 2 equations to summarize what is the best choice for … Leggi tutto Dimming LEDs (part 3/3) – The overlooked boundaries

Annunci

Dimming LEDs (part 2/3) – Sneaky non-linear events while using the PWM technique

In the previous article we tried to analyze what is the Contrast Ratio in a LED driver and how the non-idealities are giving a boundary on the minimum allowable PWM period. That was quite worth a full article, but a big part was indeed missing. Here we will go through how the PWM period and … Leggi tutto Dimming LEDs (part 2/3) – Sneaky non-linear events while using the PWM technique

Dimming LEDs (part 1/3) – Analog and digital, not analog vs. digital

While messing around with dimmable DC-DC converters for LED drivers, I had the need to quantify the contrast ratio of a dimmable light. Turns out it is not that trivial, specially when combining switching periods, transients and mixed analog/PWM dimming. Looking for contrast ratio on the internet is only useful if you want to buy a TV, not if you want to build a LED driver. Also, on the web not all information seems to be correct, therefore this article and its possible continuation is the result of long investigations and discussions between engineers.

Lino Project

I am playing with LEDs for few month and during that time some little projects were born, but now I need a system to handle the logical part and the power distribution. I simply just can't use an Arduino board, or any other development board: I need a proper power handling embedded in a small space, … Leggi tutto Lino Project

Tiny, robust, low cost, fail-safe LED driver: the Glighter-S project

It has been a while since the last LED related article. Was experimented the linear current source, its pros and cons and the field of application. Now arises the need of a small version, handling the same high power, things that are contrapposed in the linear regulator. I need something that I can bring with … Leggi tutto Tiny, robust, low cost, fail-safe LED driver: the Glighter-S project