Need advice on LED strips wiring

I thought by using two transformers will reduce the amount of current flowing through to some wires and make it less risky. I am sorry I still don't get the error/risk part of the wiring. Does it mean by connecting a the GNDs together will prevent a premature New Year Fireworks show?

That sounds like a good plan. Hope the led strip will take a 3.3V otherwise I still have to consider boosting the signal from 3.3V to 5V

I have never heard about SMD chips and have never dealt with PCB before too. Does it mean I have to use a PCB to progress further?

But like I said, instead of using two PSU's (they're not transformers...), just use appropriately heavy wires and keep them as short as feasible.

Yeah. That's where the 7414 would come in.

If you're going to get those 7414 chips you linked to earlier, then yes, you'll need some sort of PCB. It's not easy to suspend those chips in the air with wires soldered onto the leads. They're pretty small as well.

Thanks. Will do.
But what is the danger/risk of what I have done? I am still a bit confuse of the underlying principle and would like to understand it a bit more to prevent it from happening it again.

Does grounding mean the black(negative) wire from the 12V or the GND from the 230V?

That a difference exists in potential between the GND on the output of one power supply vs the other. That would mean that some parts in your system will experience a potential difference (voltage) that may far exceed their maximum ratings, and even if they don't burst into flames, there will be severe communications problems.

In this context the former. The GND of your 230V outlet is a safety measure and if your project is built into a metal enclosure, this needs to be connected with the safety GND. But it's a different topic.

When the conventional current comes back from the negative(ground) wires, shouldn't the voltage be the same? 12V(red) in and 12V(black) out. It is like there is a river(AC) and I split it into two smaller streams(two PSUs) and within the two smaller streams there are even more tiny streams(branching negative wires). Why would it potentially become a flood?

Is there a name for this behaviour/phenomenon that I can search for?

But note in giving the basic type number, we never mean the obsolete 7414, only ever the 74HC14 or preferably 74HCT14. A 74HC04 or 74HCT04 would also work.
What was also being explained above is that if you order the SMD version of the chip

rather than the "DIP" or "through hole" version,

you will need to solder it on a small "breakout" board to make connections.

That analogy doesn't work here.
In both PSU's, there's a transformer that effectively disconnects the AC side from the DC side. They're only virtually connected through the mutual inductance of the coils in the transformer. This means there's no common potential reference anymore. Any kind of external influence (e.g. build up of static, like you get on a woolen sweater on a dry winter's day) can make one PSU drift in its absolute potential compared to the other.

Try 'galvanic isolation' perhaps in combination with 'common ground' or something like that.

That's not breadboard compatible either. It's a surface mount chip. Look for a DIP chip. These have pins with 0.1" spacing, the same as a breadboard.

No, you need both. A ground wire running alongside the data wires between the strips. This does not need to be heavy gauge, it will not carry much current. But it will prevent induced voltages corrupting the data signal. You also need the ground lines back to the PSU also. These should be heavy gauge, they will carry the high currents.

No, the esp board will have caps built into it already. The bypass cap is for the chip you will use as a level shifter.

The grounding issue has confused me a lot.

Does it mean I am better to connect all negative polarities/pins of all strips. There is thick blue wire I am not sure if it makes sense or not.

Coming back to my previous setup(with two PSUs), Galvanic isolation didn't help me understand the problem directly, however, it directed me to Ground Loop which in terms mentioned Galvanic isolation is a solution to Ground Loop.

So that would mean, in my previous schema, current from Group A strips will potentially flow back to the GND through Group B(going to back GND at B or going back to Group A Circuit, not sure)


No! Safety ground (the green dot in your PSU) connects to a metal chassis if your circuit is enclosed in one. If your project is housed in plastic, wood etc. you leave it disconnected.

Yes. But you weren't having a ground loop problem. It's also unlikely you'll have problems with ground loops; you might, but in my experience with circuits like yours, it's rare for them to crop up and actually cause problems. If you were building an audio amplifier, we'd be having a different discussion.

Look, I can't explain this to you, but just remember: in a typical circuit, all grounds connect together, except for the safety ground from your wall socket which is a special case.

Ok, maybe one more try: Floating ground - Wikipedia
Essentially the grounds of both your PSU's were floating. There was however no guarantee that they would float at the same level. I.e. the ground of PSU 1 might have been lifted 75V over the other and you would only notice by the components in your circuit dying. If you tie the grounds of PSU1 and PSU2 together, they are guaranteed to be at the same level (they're connected, after all). They may still float vis-a-vis absolute ground (i.e. planet earth, or rather, the potential of the water-logged soil below your house), but that's not a problem.

Thanks @koraks

It is making sense to me now.

Because A and B are with floating ground, the potential difference between the two circuits will increase and it wouldn't be a problem if the two circuits are not connected via the signal cables.

As there is no absolute ground(the Earth) in the two circuits, current from the circuit with higher potential will flow to the other one with lower potential, rather than going back to the desired black wire.

I don't believe I am getting everything 100% correct but hopefully the core concept is correct.

Thanks you very much for all of you guys' replies, it did help me understand electricity better, way better than before.

YES!!! :smiley:

Like you said, there's some nuances/intricacies that are a bit more involved than how you worded them, but the essence is right there.

A post was split to a new topic: Led matrix help needed