Blog 1 - Magic Lightbox: Smart LED Dimmer Flyback Driver Project Introduction.

RE: Blog 1 - Magic Lightbox: Smart LED Dimmer Flyback Driver Project Introduction.

jc2048 — Mon, 11 Dec 2023 09:54:36 GMT

Nice start and introduction to your project. Personally, I like the project approach, though I'm not too good at doing them myself, so I'll follow this one with interest.

Your theory about the PLC transformers sounds plausible.

You may already have thought about this, but, if you have a single string of LEDs, a failure mode is an LED going open (or even the wiring coming adrift). The controller will then pump up the output voltage in an effort to get the current running again and may damage the capacitor (it would with a single inductor, with the transformer the situation is more complicated and the energy may well end up back in the flyback diode and snubber before you hit the voltage rating of the cap).

At this stage that might not matter, you might just accept any damaged components if it were to happen, but if you want to use the device afterwards, you may want to consider either actively recognising the situation and stopping the primary side, or rating components appropriately to avoid fire if you rely on the energy getting diverted.

RE: Blog 1 - Magic Lightbox: Smart LED Dimmer Flyback Driver Project Introduction.

DAB — Thu, 07 Dec 2023 21:59:39 GMT

Very good introduction to your project.

RE: Blog 1 - Magic Lightbox: Smart LED Dimmer Flyback Driver Project Introduction.

shabaz — Thu, 07 Dec 2023 18:25:34 GMT

Interesting project! It's also great you're investigating PLC, that's something I wish I knew more about.

If you're considering X10, I suspect you could use something like a CD4046 chip to do the demodulation of the 120kHz bursts back into pulses perhaps. I've never looked at any X10 circuits to see how they do it; maybe there are dedicated ICs for it instead.

I took apart (or tried to! I only got so far) an AC-DC converter today. It's a laptop supply that only lasts a couple of years. I've gone through several of these (Microsoft PSU model 1798), although they look well-built, there's clearly some flaw with them. After a couple of years, they only occasionally work, for a few minutes and then they stop.

(image source: Microsoft)

It's near-impossible to tear apart, the electronics are tightly packed in the thick plastic enclosure and welded shut. It's in fact impossible to remove without milling the case off on multiple edges. Anyway I don't intend to fix it, it was more from curiosity that I persisted in opening it.

It's quite interesting.. theres a couple of extra wires inside the DC output lead, which presumably controls power so that there's no sparks when the magnetic connector is attached or detached.

The power supply is mostly surrounded by copper.