Diode Ploarity over relay coils.

[Studio Mollan]

Hi,
This I can possibly almost answer myself but i want to be reassured im right,.
Im running relays with a negative supply. The safety diode should be facing the voltage source if run on a positive supply but should it be reversed when run on negative?
Thanks
/
Emil

 

[Khron]

The cathode ("band" end) should be facing the most positive voltage - in your case, i guess that would be ground?

The anode should be then facing the more negative voltage.

The other way around, the diode would be forward-biased, and flow a lot of current from ground to the negative rail (through the transistor that switches the relay on).