routercnc_MK3

[JAZZCNC]

So would the automotive type be OK?
I also looked at solid state relays but will avoid on that advice. I quite like hearing a click anyway to confirm all is well.

Yes they would work ok provided contacts rating is correct but why not just use a Din rail mounted relay as they have proper clamp terminals and are easy to access and remove.
With relay either put a doide across coil or get the type which have one built in to stop back EMF. I prefer external diode then if it blows I can just change and they cost penny's not pounds like they want to charge extra for built in version.!!

[irving2008]

With relay either put a doide across coil or get the type which have one built in to stop back EMF. I prefer external diode then if it blows I can just change and they cost penny's not pounds like they want to charge extra for built in version.!!

That's coz the diode in the relay is often a high current fast schottky diode with a known clamp voltage and thus guaranteed safe with almost any drive transistor, MOSFET, or IC - while I agree they don't cost £££s they aren't cheap and there's additional testing plus they save assembly and test costs elsewhere. An external diode would almost certainly be an 1N4xxx series of general purpose devices and cost pennies, plus if it gets disconnected more expensive driver could be compromised.