Losing steps/position, again

[ngwagwa]

Doddy - I was advised using two identical toroidals in parallel would be OK if they were identical units but warend against using different suppliers/models. I was looking at going that way as I have been unable to find a single unit with the required output - have you any suggestions?

[Doddy]

Doddy - I was advised using two identical toroidals in parallel would be OK if they were identical units but warend against using different suppliers/models. I was looking at going that way as I have been unable to find a single unit with the required output - have you any suggestions?

Sound advice from your mate.

The 2x35V transformer that you linked suffers from being in no-mans land - wiring the secondaries in series will generate a DC terminal voltage of around 100V (outside of the range of the majority of stepper drivers and too high for the small steppers on the denford). In parallel they'd through out about 50V - too much for the cheap nasty stepper drivers and too low to exploit a decent digital driver effectively. It'd work, but it's not in the Goldilocks zone.

Personally, if I was looking at CPC then I'd look at their 2x25V options (e.g. https://cpc.farnell.com/multicomp/mc...%20transformer) - wiring the secondaries in series to generate a 50VAC/70V pk DC terminal voltage for an 80V drive. Personally, I think 300VA would be sufficient but note the previous advice of giving yourself headroom with a 500w should you need to grow. Or parallel similar as your mate suggested.

BUT, much depends on your choice of stepper driver. That's really your first decision point before speccing the transformer.