[groc426]

Hello everyone,

Firstly, let me state that I have very limited knowledge of electronics, but I'm reading everything I can to get myself familiar with what I need to know. At the moment I'm putting together the final plans for my cnc controller. I'll be using a PMDX-126 BOB and an Antek toroidal power supply that will be charged via a relay (for e-stop circuit) and contactor. In fact, I'm using the circuit from PMDX's application notes as seen here (J10 is a relay on the PMDX-126):

Attachment 243860

I will have a key switch connected to the A/C mains for the PMDX-126. I would then like to have a soft latching pushbutton (correct terminology?) wired into the e-stop circuit, so that when it is pushed and power is supplied that it latches and charges the Antek power supply. If an e-stop is activated, power will be interrupted and the pushbutton will fall out, requiring it to be pushed again once the e-stop is cleared. I'm having difficulties figuring out how to accomplish this easily. Is there such a thing as a soft latching pushbutton? Or would I need to add something else in the circuit to accomplish this? If it makes any difference I also have an auxiliary contact on my contactor, CU-22-F6. Any help is greatly appreciated!

[Al_The_Man]

No1, all E-Stop P.B.'s or switches/limits should be in series with an E-Stop relay coil, it is often implemented with a N.O. push button with a retaining contact across it that is on the E-stop relay itself, which I think you are describing?
This PDF may help on control circuits in general.
http://static.schneider-electric.us/...0140CT9201.pdf
See fig 2 of p6 for a general idea.
Al.

[groc426]

Al,

Thank you! That is exactly what I'm referring to. I struggle a bit reading/converting schematics to actual wiring. I've (crudely) updated the diagram to show the implementation of the pushbutton. I've placed the new wiring in red just so it would stand out.

Attachment 243888

So, now I push the N/O momentary pushbutton, which energizes the BOB relay, which then closes the circuit to energizes the coil on the contactor. Once the contactor closes, it also closes the auxiliary contact, in which I have wired to bypass the N/O pushbutton, so that the circuit can remain closed until an e-stop is activated or power is lost. I haven't played around with Mach 3 or the PMDX-126, so I'm not sure how functional this will be, but I believe it will work.

[Al_The_Man]

That is basically it, with this set up you just need momentary E-Stop buttons, rather than the push OFF-twist ON maintained type.
Al.