LED Dimming – nothing to see here, yet, move along…

I recently picked up some 5m 12V white LED strips. Luckily, I disposed of one quickly but I still have one left that I feel I have to do something with 😛

So, I was playing with a 10W LED a while ago and I still had the tiny45 & power mosfet sitting on the breadboard next to my bench PSU. Not very exciting but, it still works 🙄

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It’s all very “meh” really. I have decided though to eschew the digital route and use the venerable 555 timer, and a pot, to provide a “dimming solution”. I need to do better at analogue so this seems a good a place to start as anywhere. Stay tuned for much frustration and blowing stuff up 😀

I have found a circuit that, it is claimed, doesn’t suffer from the frequency changing as the voltage does. That’s here.

Here’s the schematic:

From a (quick) look last night it sounds like this won’t work. However, I think the people saying that are missing the point. It has an oscillator to set the frequency, not an R-C circuit which would have frequency problems. It looks easy to build and should be interesting enough to diagnose (well, for me this is much more about the journey than getting to the destination in the shortest possible time). I know I haven’t got the same value oscillator or pot and I’ll be at 12V, not 6V, so there should be some figuring out to do.

I’ve also seen a circuit that uses 2 x 555 timers to give a constant frequency PWM where you can vary the duty cycle easily. Unfortunately, I don’t have a 1110 timer :mrgreen: but I do have one (or more) 556 kicking about if I need them.

Sad I know, but it sounds like fun to me…

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