DRC and netclasses : clearance rules between nets of different potential (lp:#983230)
Original report created by Vesa Solonen (vesa-solonen)
Flexible automatic design rules would need "differential net classes" that
means different rules for a net depending on surrounding nets.
As an example I'll explain the problem of a traditional power electronics
half bridge circuit:
HV---- [400V 10A]
|
Gh--|< [0-415V 1A] [0 < V(Gh)-V(Sh) < 15]
|
Sh-------> Out [0-400V 10A]
|
Gl--|< [0-15V 1A]
|
GND------> [0V 10A]
HV net needs "power" class clearance and width towards all nets as does
Out. Sh needs "power" class clearance towards all nets, but Gh and width
according to "control" class. Gh needs the same, but "control" clearance
towards Sh. Gl needs "control" class clearance and width.
Curently this system is unrealisable using KiCad DRC. I propose adding a
"potential class" description to net class design rules to address this
problem. Needed data stuctures for file format support and implementation
need to be discussed and designed. Interested parties are encouraged to
comment here and aim for a production ready blueprint.
Original tags: drc pcbnew
Edited by Jeff Young