Ground trace on pcb

Hi all,

I plan to use this power supply:

https://www.eleccircuit.com/high-power-supply-regulater-0-30v-20a-by-lm338/


My last question is about ground path, i don't know if i must do it with:

- pcb trace

- AWG 10 or 12 or one wire of 3G4 - European Norm with 3 wires of 4 mm2 each -

- other ?


And also why use or don't pcb - don't think or maybe mistake ? - , AWG or other.

Schematic for this circuit:

View attachment Ground-Trace.pdf


Thanks a lot.

jm

In a 20-Amp power supply, use the thickest conductor available, and connect the marked points by screws to a thick aluminum chassis. Also make sure the grounds in the AC input and DC output connectors are connected this way.

Hi jiripolivka,

Thanks a lot for your reply.

So, i must add a kind of '' bus copper bar '' - or aluminium - like in aircraft electric circuit?

Regards.

Jm

I would recommend it.

Hi jiripolivka,

I'm designing pcb copper trace with a thick aluminium bar, to withstand these 20 A.

Next question will be the best of 2 drawings planed: mainly sharing load on the first or the entire resistors net.



I'd like to use Case 1 - one single pcb copper trace + aluminium plate - due to space constraints, than Case 2, is it a good choice?

In Case 1 , is current sharing evenly in all the resistors, or only through the first one????

Avoiding frying some component or pcb trace would be nice ..

Also, copper and aluminium are dissimilar materials, so, no electrolytic corrosion?

Thanks you for your help, it's great.


jm