Eeschema assumes all I'Cs are same supply, when not

I’ve added screen shot to hopefully be understood. Simply put the IC’s on the screenshot are 2.5VDC and an NE555 which is on a different supply and no connection to the 2.5V rail.

EESchema places the 555 as part of the 2.5V rail accidentally picked up on PCBnew no errors or anything given. I have a 12v rail and 2.5V rail joined by a resistor.

The cct on the screen shot is trimmed down to simplify it.

I can’t believe this is a bug for it’s a pretty bad one and if so, Imagine having had it auto-routed or had the PCB made without it being picked up.

Am I doing something wrong.

This is the bad NE555 symbol design. The only thing you may treat as “fail” (which is not) from KiCad Eeschema is to connect everything labelled VCC together.

BTW: Do not place wires which passing trough symbols body like you do for C13.

Ok, I have KC 4.0.5 and that’s the only NE555 symbol that shows up.

Ok, Need to remember! I changed the VCC on the 555 to +6V and added a power flag and it seems to have fixed the issue in PCBNew. Will check. I gather having first flagged the IC’s with 2.5V it took that as being VCC and not 12V.

For the hell of it I removed R18 the zeners resistor and added a 12V power symbol after the fuse. It has now changed VCC to 12V and I have a direct connection between 2.5 and 12V O’well seems like something important to remember.

Will do. Thanks.

One does not exclude the other. Remember that all symbols were designed and committed by users.

Ok, though I thought they would have gone through a review prior to being included.

Good to know. Thanks.

Sadly some of the symbol libraries are in a quite bad shape. (especially the symbols in the logic family libraries.)

If you want to look into modifying the symbols, in this topic i described a way to do it efficiently.
It is not as much work as you might think.
(I also described the finer details on how this “feature” you discovered works.)

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