Signals & Electrical
Normally Open (NO)
A contact that is open when it is not being activated.
IN ONE SENTENCE
The circuit is normally broken and closes when the device operates.
In normal English
'Normally' means the unactuated or de-energised condition, not what the machine usually does during production.
Why would I use it?
Use it when you want the circuit to make only when a condition is reached.
THINK OF IT LIKE…
A door that starts open and closes when triggered.
Related terms
Normally Closed, changeover contact, relay
STILL NOT SURE?
Tell us what you're trying to do.
You don't need to choose the technology first. Tell us what needs connecting, measuring or monitoring and we'll help work backwards from the job.
Help me find the right technology