Stepper Motor Maximum Speed and Power Calculator
Stepper motors are normally used for positioning, and are not known for their speed. This calculator computes the maximum speed of a stepper motor, which is limited by the time it takes for the coil to energize to it's maximum holding current, and then de-energize as polarity flips.
Equations:
Current through the coil is proportional to the time that the voltage has been applied, and inversely proportional to the inductance.
I= V*T/L
T= I*L/V
For one step the current must go from 0 to Imax and back to 0, or alternatively from -Imax to +Imax.
I= 2*Imax
T= L*Imax*2/V
T is the number of seconds for a single step.
To compute maximum revolutions per second - divide seconds per step by steps per revolution.
Rev/sec = V/(L*2*Imax)/(steps/rev)
Pmax= 2*Imax*V
Pmax occurs not when the motor is going max speed because the current is a triangle wave. Pmax occurs when the slope of the current is small compared to the on holding time of the step pulse.
