Connection between AXBB-E and plasma torch by relay

[JAZZCNC]

Section 7 of the manual on page 18 says the 24V supply can be anything between 12 and 24V. 12V works fine as long as the connected devices are designed for it. It's what I use without any problems.

See you learn something every day, didn't spot that Kit, suppose should RTFM... . . .But think 24V is recommended hence why it says 24V.

[Kitwn]

See you learn something every day, didn't spot that Kit, suppose should RTFM... . . .But think 24V is recommended hence why it says 24V.

As you know 24V is more common in commercial machines, and there will be an upper limit on the voltage the AXBB-E internal transistors can survive. 12V is more common in cheapskate machines that use an old PC case, including it's 5V/12V PSU to power the controller! In that case the simplest way to wire relays is to use 12v ones connected to the same supply, which is how I control my spindle on/off. I have a 12V relay with 240V AC rated contacts which uses one contact pair to signal the VFD and the other pair to switch 240V AC to the dust extractor.

The isolated outputs are almost certainly just open collector transistor outputs built into opto-couplers which can be used with any voltage up to their rated limit. The handbook does cover the use of different voltages (section 9 at the bottom of page 21) and you could use different voltages for different outputs if necessary, possibly including 5V if you wanted to use one as a pull-down to feed other logic circuits, though that would need testing before being certain.


The most important thing with electro-mechanical relays is not to leave out the flywheel diode. A lot of the relays mounted onto a base have them already fitted but an external one is needed if not. You risk damage to the AXBB-E output without this protection. However, another possible reason for the relay not working is that if it has a diode fitted the polarity of the relay connections must be correct otherwise the diode will short-circuit the coil when you try to energise it.

EDIT: Just had a look at the Cncdrive forum for any information re the outputs and they describe them as 'NPN switches' which agrees with my comments above.

[dazp1976]

suppose should RTFM... . . ..

Indeed.
Mind you. If everyone did actually RTFM's, they might not need the forums so much.
That would be a little boring wouldn't it.

[Kitwn]

Indeed.
Mind you. If everyone did actually RTFM's, they might not need the forums so much.
That would be a little boring wouldn't it.

Great wisdom, framed as humour.