Transformer Selection
 

The more I read up on this topic, the more I'm confused... Please do remove this thread if it was mentioned elsewhere.

I am ok with the followings...
The 32*sqrt(Lcoil) = Vdc
and 2/3 of total current rating
Worked find to me until I look as the VA rating...

It look obviously, the Output stage of the driver behave in Class AB, please correct me if I'm wrong.

I read of 300VA is enough transformer... but when I do the sanity check on the maths, I get some bigger VA the 300VA...

I will receive my alternative stepper motor 86HS9801 made by Leadshine, the Lcoil is 4.1 mH, so 32xsqrt(4.1) is about 65V, The Current is about 6A, So for all the motors, 4*6*65*66%=1029VA.... :eek:

I want to look at this at another angle, Since the 300VA tranny is enough, meaning MM use less the 300VA to move the axis around... We can get away with the current as long as the tranny has 300VA rating with the suitable Vdc?

I have a "new" EI core, Double bobbin, 36Vac, 15A, 540VA tranny in my junk box... I weight quite a bit... 6kg... should put out just under 50Vdc.

My alternative driver is M860 Vdc 20~80V, typical 68V. Max output current is 7A.

I won't fry my tranny will I?

Any help is appriciated...

Cheers

They take a long time to fry, unless you have made a huge mistake.

Plug in, switch on, and check often for overheating. Some fuses will give you extra peace of mind.

thank Gerald.