I use a voltage regulator LM7812 with my power supply. If I connect the +12V and the PWR_FLAG to the output of the LM7812 then I get the „Error: Pins of type Output and Power output are connected“. If I remove the PWR_FLAG then I get the message that the power input in the schematics is not connected to anything.
One work around this problem is to place a 1 Ohm resistor (R2) between the LM7812 and the PWR_FLAG. In this case the error message goes away, because the LM7812 output is not directly connected to the PWR_FLAG.
Is there some other way to omit this error message, because actually I don‘t need this additional 1 Ohm resistor (R2) in my schematics?
Gawd! I hare that damn PWR_FLAG requirement in Kicad I’ve never under properly understood stood why its needed.
Anyway, what I do is set up the PWR_xxxx flags off to the side of the schematic. So up in the corner I set up PWR_FLAG & PWR_GND to their own designator - VCC, +5V, GND whatever.
This seems to work for me - I do it automatically now
Hope this helps
Can you please show us the pin table of the LM7812CV symbol?
Ha, eelik came to the same conclusion. In addition I think the INPUT pin should be type Power Input, and then there should be a PWR_FLAG on the net it’s on.
There is a LM7812 in the standard library. Did you go off and make your own?
I downloaded the LM7812 symbol from snapeda.com. The INPUT was set to Input, GND to Power input and OUTPUT to output. I changed the OUTPUT to Power output and I could remove the resistor and the PWR_FLAG, without an error.
There is also a LM7812 in the standard Regulator_Linear library, but here I need a PWR_FLAG on the input side and on GND, in order to get it to work.
The PWR-Flagitis of KiCad can be pretty confusing at times.
I remove the flag if I want to print a hard copy. But, sometimes PCB projects can be expensive and I personally want all the auto-error checking I can get before I throw my money at a new project.
