The recommended gecko drives can take 20 amps and 18 to 80 volts, so a 60 volt 20 amp unregulated toroidal transformer will be ideal. Don't use over 60 volts, to leave headroom for voltage spikes. We usually also will need one or two 5 volt regulated DC power supplies to power the breakout board, components, and signals. I used Unregulated Linear 1200W/60VDC/20A Toroidal PSU (KL-6020) | Automation Technology Inc for $189.00 It comes with one regulated 5 volt output. You can use less volts and amps and or switching power supplies. Higher voltage means higher top speed. More amps means more acceleration.