pminmo BOB and NC E-Stop switch

[kiltjim]

I have a BOB built and everything is running great. Except that I do not have an E-stop switch hooked up yet. I have some excellent take-out components from some equipment and would love to use what I have. Unfortunately, the E-stop switch is a NC switch, and the circuit calls for a NO switch. Is there a way that I can change the circuit to use it?

I was also thinking that having the circuit take NC switches would be a safer method. This way I could hook up several switches in series, and then any single switch would cause the circuit to stop.

Any suggestions?

[Al_The_Man]

E-stop circuits are generally wired with NC devices as a safety precaution. Also it conforms to the code recommendations.
You can change the logic by using all the NC safety devices in series and they would pick up a relay with a NC contact, this contact would be open in normal operation, closed on e-stop.
Al.

[kiltjim]

Here I was trying to figure out a complex circuit to use the thing, and never thought of a relay. Leave it to someone else to point out the obvious.

Thanks Al!

[pminmo]

You can use a normally closed switch, in fact it is preferred. Not sure where I might have communicated that you can only use normally open?

[kiltjim]

Maybe I am misinterpreting.

If the switch is closed, the circuit latches (all the time, unless the switch is pressed). If I press the reset switch, it momentarily un-latches (machine could run), but then latches again. I tried simply changing the way that Mach3 sees the signal, but no good.

Am I doing something wrong?

[pminmo]

Oh, your referring to the website version, I didn't think about that one. Too many days have passed..... Skip the circuit, just use Pad 15 as the input, the other side to a gnd pad.