TomGeorge:
You will need an input to tell the timer to start the monitoring process.
Good point, possibly I could get that input from its auto on function from PMC, momentary switch.
Machine is a Makino cnc using 24vdc I/O.
Started this out as...
Trying to detect the halt of 3 phase motor.
My first thoughts to precisely fuse one leg, if it stops the rise in current would blow that leg and let overload protector do the rest.
Friend of mine suggested arduino might do this as well.
It does sound interesting, I ordered a starter kit to try.
kmich:
Friend of mine suggested arduino might do this as well.
It does sound interesting, I ordered a starter kit to try.
I'd suggest not worrying about the specifics of your project until you have your mind round some of the examples. (That said, of course you'll keep the project in mind as you work through the examples, and mentally store some thoughts for when you get to the project.)
There are loads of examples here, and they're all repeated in the IDE itself under File > Examples.
Google "speed switch", that's a common application in industrial control, I've used ones made by Red Lion. Usually they sense a pulse from the rotating part and switch when the pulse frequency falls below a preset value. Simple but pricey, you can roll your with an Arduino.