Hi Fellows,
I want to know what you people know and suggest about when it comes to framing a PCB that includes in its circuitry a uC and AC control design?
Generally Ithink they need to be opto isolated but would be better if both are on a separate PCB
What sort of AC voltage? Are you talking about mains? There are many sources of AC other than mains.
What sort of AC voltage? Are you talking about mains? There are many sources of AC other than mains.
Yes the source is mains but I think the nature of AC remains the same irrespective of the source.
but I think the nature of AC remains the same irrespective of the source.
Yes but how you handle it in a project does not remain the same.
For mains there must be at least a 0.2" gap between any track carrying mains and one on the low voltage side to comply with safte regulations. That includes pins on an opto isolator.
I've generally had the experience that Optical isolation tends to be the best, since optics aren't disturbed by electric noise. However, don't forget you need to power each side of the optics. Make sure you get an isolated DC Supply and you should be good to go.
Thanks mike ane mirith
NI$HANT:
Yes the source is mains but I think the nature of AC remains the same irrespective of the source.
I respectfully disagree with this statement wholeheartedly. AC in and of itself is not harmful and doesn't require any special care WRT safety. High-voltage does, and that's regardless of its frequency.
There are attributes that are common to any AC -- like how you approach induced noise, and having to deal with alternating polarity (although it could be biased above Gnd, so even that's not entirely accurate.) But from a safety perspective, I don't worry about keeping safety distances from my line-level audio inputs. On a mains PSU board though, that's a huge concern.
OK, I said mah piece. 