It is one of the most exclusive varieties of motors that functions in any setting. It is usually used for various different purposes as it involves low cost, simple construction, high consistency and better performance at lower speed. It is also recognized to be the digital version of the electric motor.
Basic Advantages of the Stepper Motor
- Stepper motor has numerous advantages and some of the most significant advantages are mentioned below:
- If the windings are energized the motor has full power even at fester position.
- The input pulse and the rotating angle of the motor are comparative to one another.
- The stepper motor is measured to be quite consistent as it does not include contact brushes. The stability of the motor depends on the bearing of the motor.
- These motors and stepper driver are also recognized to be responsive to different functions included in the motor such as start, reverse and stop.
- These motors can work at low speed.
- Different kinds of rotational speeds can be achieved by using these motors.
Different Types of Stepper Motors
There are basically 3 varieties of step motors which contain the hybrid, changeable reluctance and permanent magnet. The hybrid motors are measured to be the most efficient type of motor as it includes the most excellent features of both changeable reluctance and the stable magnet.
The hybrid motors are extensively used for a range of commercial purposes which comprise CD players, computer disk drives, printers & so forth. These motors are also used for different scientific and business applications such as in automated wire bonding & cutting machines, choose and place machines, machine tools, liquid control devices & in the field of robotics.
The permanent magnet stepper has a stable magnet rotor which is cylindrical in form. It is frequently used in computer printers for the reason of advancing papers. The rotor in the stable magnet stepper has a permanent magnet with many poles.
Why Use a Stepper Motor?
1) Open-loop control makes the motor simpler and less expensive to control.
2) The rotation angle of the motor is comparative to the input pulse.
3) Precise positioning and repeatability of movement.
4) Extensive ranges are accessible since the speed is proportional to the regularity of the input pulses.
5) Quality stepper motors have an accuracy of 3 to 5% of a step & this inaccuracy is non-cumulative step to step.
6) Outstanding response to starting/stopping/reversing.
7) If the windings are eager the motor has full torque at standstill. When the load is unswervingly coupled it is possible to get extremely low-speed synchronous rotation.
8) High MTBF – since there are no contact brushes in the motor.
Bipolar stepper motor
A bipolar has one winding per stator point and a two-phase bipolar stepper motor has four fronts. There exists no regular lead, so the current can’t be overturned through the winding. Current flow direction trouble can be solved through H-bridge incorporated circuit. Well, stepper motor current drawn is fairly high which needs at least 10 times of 15mA.
So in such case, an exterior driver IC is able of handling such high currents. One more reason for using H-bridge is that when current changes its way spikes are produced. Such high spikes are not tolerated by microcontroller pins. Consequently, to protect microcontroller pins H-bridge is essential.
A bipolar stepper motor has two polarities positive & negative. Every polarity has positive and negative voltages ability. These motors are extremely complex because of the H-bridge driver IC which helps in the forwarding current flow from overturning current.
The torque produced by the motor is quite high. Bipolar when interfaced with a microcontroller, need only four pins to drive. Supply is given about 5 volts and extra voltage to operate the motor. Enable pin is confirmed for using both the drivers of the included circuit.