Most of my house lighting is now LED-based, and most of that uses various shapes and sizes of incandescent bulb replacements. But for a few cases, I’m using pure LED designs – in particular – white and RGB strips. These require power supplies and, optionally, controllers. Keep reading as I open up a few examples I bought straight from Chinese distributors.

I decided to try building something futuristic: a white plexiglass sheet backed with LED strips, and with touch controls for brightness.

My plan was to build µC-based touch controls from scratch, but I couldn’t resist taking the easy route after discovering LED touch controllers for under $20 (USD), shipped.

When I discovered the line of touch dimmers, amidst the various styles of single-channel and RGB models, was, sure enough, one that fades between cool and warm white. So, that’s what I bought…just in case. It cost no more than a single-channel unit.

The main board’s µC or ASIC here has been obfuscated, but a bit of tracing might reveal its basic identity (a PIC perhaps).

To make my crazy plexiglass design work, I’ll also need a power supply. Here’s what I sourced for about four bucks

Based on a bit of circuit tracing, I’d guess it’s a simple flyback design. In fact, there’s no obvious control chip at all, unless it’s masquerading as a transistor or optocoupler.

Notice that the incandescent bulb (yellow line) does not dim linearly with power. It’s main achievement is that it does dim down to zero. A CFL does a better job of dimming with power, and the Samsung LED light is very good, dimming quite linearly with power. However, it drops out at just under 20% of its max output light. (Which, however, more than meets the L-Prize spec.)