Quote Originally Posted by Clive S View Post
What size toroidal, what motors and what drives are you using? Too many varables
Hi Clive,

The drives and motors I'm using are the Leadshine Hybrid Stepper ones, HBS86 drive and 60HBM30-1000 NEMA24 motor. The drive has a maximum voltage rating of 80VDC. The toroidal transformer which I haven't got yet will probably be a 45VAC+45VAC 1000VA one from Airlink transformers. I did the following calculations to arrive at this, and if you see any obvious errors can you tell me.

The motors are 2 phase with a current of 5A per phase so 10A per motor. The motors have 4 power leads which means that they will probably be series wound so I think that the motors will pull approximately a third of the maximum, so about 3.3A per motor. I'm using 4 motors so the total current draw should be about 13A.

For the voltage I took the mains voltage +10% as a worst case so

45VAC + 10% = 49.5VAC
49.5VAC + 4% for transformer regulation = 51.5VAC
51.5 multiplied by 1.414 = 72VDC
72VDC - 2.2V for the bridge rectifier drop gives roughly 70VDC output.

Hopefully this is alright and I haven't made any obvious errors.