On Wed, 7 Apr 2021 23:46:23 +0100, John Rumm
wrote:

On 07/04/2021 21:42, ARW wrote:

Am I correct in saying that it does not matter if there is a LN reversal
on the input?

Correct...

It will always have a correct +/- DC voltage.

Yup.

In fact if you are designing DC powered kit that runs from an external
supply, then sticking a bridge rectifier on the input even though you
are only ever expecting DC rather than AC, is a way to ensure your kit
will never see the input polarity reversed if used with the wrong PSU.

I did that with a piece of battery powered kit I used to build to go
with my guitars. It used an off-the-shelf box with built-in battery
connectors that didn't have anything physical to prevent you putting
in the battery the wrong way round. Rather than use a (much) more
expensive box, I added a bridge rectifier into the circuit. Belt.
Braces. Piece of string in pocket.


Nick