At this part will be studied about last part from motor drive train stepper. This circuit basically only to be switching current circuit flowing circumference at motor stepper. Giving sequence of data at this stepper motor can control direction of rotation from this stepper motor. Addition of velocities at motor stepper can be done by the way of increasing giving frequency of data at circuit switching current.
This control circuit later is not connected direct with circumference at motor, power supply circuit, and controlled circuit digitally in the end determines when circumference wanted in condition of OFF or on. Besides only applies transistor switching are, now have been available of driver motor that is of course is destined for motor stepper, more knowledgeable with H-Bridge. This component usually applied at motor stepper type bipolar, even though doesn't close possibility applied at motor stepper other type.
Driver Variable Circuit of Reluctance Motor figure;
Bobbin at motor stepper has the same characteristic with other inductive load characteristic. On that account when there is current passing motor bobbin, cannot be killed at once without yielding a real transient tension height. This condition usually seems to be with incidence firework sprinkling (when using DC motor with big power). This thing hardly is not wanted by can destroy switches causing need to be given addition circuit to limit emerging transient tension. On the contrary when switch is closed hence there is current streaming into motor bobbin and will yield increase of tension slowly.
To limit tension spike is emerging hence there are two alternative of the solution is with parallel at motor bobbin with second diode and alternative is by using capacitor attached by parallel with motor bobbin stepper.
Figure 2;
Diode that is attached by the parallel must be able to overcome current back of happened when open switches. Diode applied cans be in the form of common diode is used like 1N4001 or 1N4002. If it is applied diode is having characteristic 'fast switch' hence need to be given addition of capacitor attached parallel at diode.
Installation of parallel capacitor with motor bobbin can cause spike generated will cause the capacitor charge so that tension spike happened will not go out but damped by this capacitor. But most importantly is this capacitor must be able to arrest surge current at the time of happened spike. Surge current is a real big abrupt current emerging in parallel with tension spike. Capacitor value must be selected at condition of where inductance value from biggest stepper motor bobbin. This is motor characteristic stepper with variable type reluctance where the inductance value is fickle is depended from the aspect of rotation at rotor axis. Addition of capacitor so that precise will form a resonance circuit which can cause improvement of torsion at motor type this.
Driver Uni-polar Permanent Magnet and Hybrid Motor Circuit figure;