Local power nets in duplicate hierarchical design

[Kris_EJ_Pol]

Hello,

I would like to create a schematic design with certain properties, and I can’t figure out how to do it.
After some searching through various forums, the closest is this:

Multiple Copies of Hierarchical Sheet

This should be a quick question, but I couldn’t find a specific answer in the forums. I have several sub-circuits that I want to have copies of in my schematic (a whole set of control circuitry to drive power FETs; each FET needs the same drive circuitry repeated). I’m trying to use hierarchical sheets to accomplish this. If I create multiple sheets with different sheet names (Sheet: Control1, Sheet: Control2, etc.), but have them all point to the same file (File: Control.sch, File: Control.s…

My goal is as follows:

I want to make a hierarchical design where a subsheet occurs multiple times.
This can indeed be accomplished by making the subsheet symbols point to the same sheet.
This is a great way to assure consistency: if for example a bug is found,
it only needs to be repaired once. The design in the subsheet is rather large,
so I would like to use local power nets to keep the schematics as simple as possible.

Additionally, these multiple instances need to be connected to separate power supplies.
So, the single subsheet is given explicit hierarchical power pins,
and every instance is hooked up in the main sheet to the multiple power supplies.

However, this combination leads to a problem:
as the same subsheet is used, the names of the power nets in these sheets are the same.
And as the names of power nets are global, they all get wired together.

So my question is if it is possible to have power nets with local naming.
And if so, how best to go about it, of course.
If it is not possible, then I will have to refrain from using power nets in my subsheet,
but that would really make it much harder to read…

Many thanks in advance for your advice!

[bobc]

@Kris_EJ_Pol

So my question is if it is possible to have power nets with local naming.

Yes, if you use local net labels instead of power symbols. (Although I don’t see a problem with power nets all being connected)

If you want to isolate power rails on the PCB, then you would need to use net ties.

[Kris_EJ_Pol]

Yes, although I have not used local net labels yet, I think I understand what you mean,
and it would be a good alternative to local power nets. I’ll give it a go right away.
Many thanks!

[paulvdh]

I have some dificulty imagining why you would want to separate the power connections. from the sub sheets.
Would you care to elaborate on that?

After re-reading your post:
Different power supplies for different sub-schematics seems logical.
But at least the GND has to be shared, or you need galvanic isolation (opto couplers, transformers or other).

Can you post some screenshots of your schematics and why / how you want to separate those power supplies?

[Kris_EJ_Pol]

@paulvdh

Different power supplies for different sub-schematics seems logical.

But at least the GND has to be shared, or you need galvanic isolation (opto couplers, transformers or other).

Sure, there is no objection to connecting the ground lines of the subsheets.
I do want to separate the positive and negative power supply lines
so as to enable better isolation, to avoid cross-talk between the channels.
So it is precisely as you thought, no galvanic isolation needed.
Sorry if my earlier description was unclear!