Confirming PSU spec for steppers.

[Jonathan]

It's 625VA. It might not be very useful but it's more useful than detrimental, I suppose.

I understood the problems with thermistors to be the time needed to cool down again if they are not taken out of the circuit - if the PSU is shut off but restarted within quite a short time, the thermistor doesn't offer enough resistance to work as an effective soft start.

You would be fine with 625VA and no soft start circuit, so if you restart the PSU with the thermistor still hot the current is still going to be less than without anything, so either way it's not a problem.

I'm reading everywhere that zero crossing is the worst thing with regard to inrush.

Reference?

if you really find a series resistor necessary, just use a resistor bypass relay powered from the DC side. By the time the DC is high enough to power the relay, any surge from bypassing the resistor should be pretty minimal.

I used that strategy recently to charge a 0.06F capacitor bank from the mains via voltage doubler ... nice and simple. Pity what it was powering blew up.