Enhanced control methods
Sinusoidal power switching.
When the stepper motor is being used in the previous examples, we basically send full power to a coil 1 direction and then switch it so we are sending full power to same coil but in the other direction. We are basically sending a square wave and then reversing it. This makes it difficult for the incoming power to energise the coil.
Sinusoidal switching is where we energise the coil slowly using pwm and then slowly reduce the power before switching the powers direction and slowly energizing and de-energising again.
It still takes some time to do this but it would allow us to control whats happening better and allow is to squeeze as much torque as we can from it.
Using a system like this in full step mode would let us be de – energizing 1 coil while the other is fully energized, then once the first coil is fully energized reduce the power to the other coil creating a system similar to half stepping but hopefully keeping the speed and torque.
Most of the expensive stepper motor control boards use sinusoidal energizing methods along with trapezoidal stepping methods.
If anybody has anything to add or spots any mistakes you can post it or PM me in the forum