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Good day,
I want to connect AXBB-E with plasma torch by mechanical relay, like in AXBB-E manual on page 22. When I have made circuit by first scheme on this page, nothing did happen.
AXBB-E 24V power input is powered by 12V.
What should I fix in my circuit?
Sincerely,
JBL_LG
P.S.: Relay coil rated voltage is 12V DC.
Why would you use 12V when it requires 24V.?
If you are powering a 12V relay then you still need 24V for the AXBB-E outputs to work but use the 12V supply for the relay by connecting both 12v and 24V Zero volts together then connecting the 12V + to the relay coil V+ terminal, then run a wire from AXBB-E output you are using to the Relay 0v terminal.
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.Quote:
Originally Posted by JAZZCNC
One reason the output might not be working is if you are attempting to use output O1. This has it's own purpose and you must use O2 - O8 for relays etc. I made this mistake myself when I first set up my AXBB-E. The manual does say so but not as loudly as it might.
O1 is the charge pump and I believe it just draws that pin down to ground when it gets a signal from the PC. If it looses connection that pin is not active so it is designed to be used for system safety.Quote:
Originally Posted by Kitwn
See you learn something every day, didn't spot that Kit, suppose should RTFM...:dejection: . . .But think 24V is recommended hence why it says 24V.Quote:
Originally Posted by Kitwn
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.Quote:
Originally Posted by JAZZCNC
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.
Indeed.Quote:
Originally Posted by JAZZCNC
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. :tongue:
Great wisdom, framed as humour.Quote:
Originally Posted by dazp1976