I am using a L298N shield together with an Arduino to drive a 42mm 2 phases bipolar stepper motor. The driving voltage for the motor is 12V and the logic voltage for Arduino and the L298N shield is 5V. This is the datesheet of l298n
Everything seems work fine, the stepper motor moves under control without losing steps. However, when I try to measure the voltage across and current through one phase of the stepper motor, I find that the voltage is just about 2.4V and the current is just about 0.075A, which is far from the specified phase voltage and current rating (12V, 0.4A / phase) of the motor.
I want to know that is this a normal case for a L298N shield? Does the L298N have a relatively low efficiency?
If I increase the driving voltage for the motor to 24V / 36V, would this help to increase the output voltage of the L298N shield? But would this put the L298N to a even lower efficiency?
Are there better ways to put higher voltage and current to a stepper motor?