PSU Assistance

[Clive S]

Amazing, I would go in exactly the opposite direction and replace toroidal with switch mode

Transformers make everything squiffy, heavy and complicated.

Well from the drive info:-

Regulated or Unregulated Power Supply

Both regulated and unregulated power supplies can be used to supply the drive. However,

unregulated power supplies are preferred due to their ability to withstand current surge. If regulated

power supplies (such as most switching supplies.) are indeed used, it is important to have large

current output rating to avoid problems like current clamp, for example using 4A supply for 3A

motor-drive operation. On the other hand, if unregulated supply is used, one may use a power supply

of lower current rating than that of motor (typically 50%
～70% of motor current). The reason is that

the drive draws current from the power supply capacitor of the unregulated supply only during the

ON duration of the PWM cycle, but not during the OFF duration. Therefore, the average current

withdrawn from power supply is considerably less than motor current. For example, two 3A motors

can be well supplied by one power supply of 4A rating.

So take your choice

[Robin Hewitt]

So take your choice

I always do

I went off transformers for CNC when I tried to calculate the voltage to buy and what value for the smoothing cap.