I have some kind of interest in electronic projects, whether hobbists or a professional ones, which are based on standard and always available sub-components. Those always available parts are also called jelly bean components, like resistors, capacitors and cheap basic parts, like op amps (including in my opinion also LM741, LM324, even TL081 and the … Continue reading Switching converters nostalgia: a brief history
analog
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 … Continue reading Dimming LEDs (part 3/3) – The overlooked boundaries
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.