Confirming PSU spec for steppers.

[irving2008]

Just out of interest, if you wanted to get 5V out of that system as well, would you run a 7805 off the +24v circuit, or should that circuit be kept purely for the relays/e-stop?

Depends. The 24v is present as soon as the primary switch is turned on. If its OK for the 5v to be present too, and the current drawn is small, say < 0.1A, then yes. Otherwise I'd run a small 5v supply off the aux AC.

Incidentally +24 is nominal. A 15v transformer would give 21v, an 18v transformer would give 25v. A 3VA transformer is more than enough (200mA output). The smoothing capacitor need only be 470uF @ 40v rating and needs no bleed resistor. The relays are 24v, 600ohm coil, needing 40mA each, with 7A 4PDT contacts.