Re: Step2Linear
The power supply needs plus and minus 14 volts so the 20 volt ac yields 28 volts DC with a centertap, which is +14 and -14.
I say a 20 volt transformer because it will usually be about 22-23 volts AC unloaded which will still be below the absolute max which is 36 volts DC.
The boards don't produce any heat, so you can mount them anyway.
Also i include a programming cable with the order so you don't have to make one.
Larry
Manufacturer of CNC routers and Viper Servo Drives
www.LarkenCNC.com and www.Viperservo.com