Looks quite useful. I wonder if the danger is really that great.
I understand what you mean about doing a seperate box, however then there is no point of a shield at all, the only actual logic on the board is the arduino pins to drive the opto-couplers
I've been looking at doing some lighting control myself and have been researching building something like this. ...I agree an SSR would be ideal, except in this particular instance I'd like the ability to dim lighting.
I love input, but hate when people try to crush ideas just because they do not like it.
Is there a danger? Yes.I'm I worried? No. ...
PS - People who write...do not inspire me with confidence in their research!I'd strongly advise such people NOT to "build something like this".Especially when an SSR should be ideal for dimming lighting.This thing is basically a homebrew quad SSR, but 100% exposed and bringing mains electricity intimately close to the Arduino (and anyone 'interacting' with the Arduino).
About the idea of dimming by cycle switching? It really might be flickery, that way. The lighting dimmers that were the source of this idea can switch at some point into each cycle using thyristors. which leaves a smooth dimming effect.
I had assumed that basing the switching on timing without zero crossing detection that it would drift. I guess I should just pick up an SSR, have a play with it and see what happens.