Build Your Own Clone Message Board

Can someone please explain what the difference is between "normally off" and "normally on" when it comes to momentary SPST footswitches?

I'm wanting to do a bulk order, but one document says "normally on" (luckily, I have some of these), but the other build doesn't specify.

Does it really matter?

Yes it matters. Normally on means that with the switch sitting there, not being depressed, the contacts are connected. Press the switch and the connection is broken. Normally off means that with the switch sitting there, not being depressed, the contacts are not connected. Press the switch and the connection is made. Depending on what you're doing, one switch is better suited for the job than the other. I have seen many more applications of normally off switches than visa verse, but details count.

Normally off is often abbreviated as NO = normally open.

Normally on, or normally closed = NC.

So if you see NO or NC, that's what they mean.