daft question on LED indicators and high VDC

[irving2008]

I thought there's two ways:

I might be wrong though:)

T.

Umm.. the first way is correct - the resistor and zener are interchangeable in this diagram, just different ways to drop the volts.

The second is unnecessary as uses two components when one will do. LED doesn't need regulated supply so the zener is unnecessary.

Irving, good idea using zener but should the connection go like this ?

supply +ve to lamp +ve
banded end of zener to lamp -ve
plain end of zener to supply -ve

You could, but convention is that indicators always have one side grounded as often, in times past, the panel was the ground.

Or you could use one of these:- http://www.amazon.co.uk/99-9V-Digita.../dp/B008KXMNTU ..Clive

You could, but a pain to mount, unless you're CNC'ing the panel and overkill :lol: