Stepper Motor Modes of operation
There are three excitation modes that are commonly used with the stepper motor - full, half, and microstep. Let´s discuss each mode:
Stepper motor - Full Step Mode
If all the coils of the stator are always energized in any step, then you call this Full Step mode. Each coil can be polarized in two different directions. The advantage of full-step operation is a constant torque for each step.
Stepper motor - Half step mode
A higher step resolution and therefore a better running performance can be obtained in half-step mode. An additional step can be inserted by switching off one motor coil is completely off. The disadvantage, however, is the non-constant torque.
Stepper motor - Mircostepping mode
In microstep mode, a basic step of the motor can be divided many times. If the voltages for both coils are phase-shifted by 90 °, a smooth operation of the motor is achieved - the resolution is increased and the motor characteristic is optimized. Unfortunately, the torque decreases by about 30% compared to the full step.
Questions about the power module:
- What tasks do the diodes parallel to the transistors have?
- Which transistors are particularly used in power electronics?
- How to prevent the two transistors causing a short circuit?
The diodes serve as freewheeling diodes to protect the electronics, as voltage is switched on and off to the motor coils.
The types of transistors often used in power electronics are the MOS-FET´s and IGBT´s.
The two transistors connected in series are interlocked to each other. One of these transistor has a negated signal at its gate.