Transformer Specification

[milton d]

Hello all,

Can anyone give me the amperage rating for the power transformer on my 1996 Denford MicroMill? It's a USA spec model with a Smartstep/3 controller. Being USA spec, it has a 110v input and the board needs max 28v but I don't know what the amp rating is.

I've looked over the schematic .pdf downloads but it's not there nor is the amp rating shown on the machine's transformer label.

Thanks!
Milton

[angel-tech]

transformers normally have a va rating, is this shown?

[milton d]

Thanks angel, I looked again and didn't find a va rating anywhere but upon further review of one of the SmartStep/3 .pdf downloads available here in the forum, I found "18-28V AC, 3A input" so that's what I'll look for.

I found a 115V/28V 3.67A open frame transformer on eBay for a good price. Do you think the higher amp rating would hurt the board or does it just use whatever amount of power it needs? Forgive my electronics naivete; obviously not one of my strong points, if I have any.

[angel-tech]

it'll just use what it needs.

[Steve]

Yes the higher A rating is better. On the older smart steps the tranfformer was on the edge of performance and if you were to upgrade to a newer controller the transformer would have to be upgraded. The transformer we currently fit is 300VA.

As long as you get one with the same or higher power rating you should be OK.