I will pay for the following article Driving Unipolar Stepper Motors. The work is to be 5 pages with three to five sources, with in-text citations and a reference page. Stepper motors have multiple “toothed” electromagnets around the center metal gear. in order to make the motor’s shaft turn, one electromagnet is powered that makes electromagnets teeth magnetically attract the gears teeth. When the gears teeth are therefore aligned to the first electromagnet, they are offset from the next electromagnet. When the next/following electromagnet is turned on, the first/previous is turned off hence the gear turns slightly to align with the next one hence the process is repeated. Each slight rotations is known as a “step,” these make stepper motors to be turned at a precise angle.

There are two arrangements for the electromagnetic coils in a stepper motor: unipolar and bipolar. a unipolar motor has four separate electromagnets. From figure 2.0 in order to turn the unipolar stepper motor, coil “1” is given a current burst (pulse width modulated signals) then it is turned off, and coil “2” given current, and then coil “3”, “4”, to “ 1” again in a repeated pattern. The current is sent through the coils in a single direction. hence ‘unipolar’ [1]. However, in the lab, the unipolar stepper motor was only used.

The circuit was connected as shown in figure 3.0 below on the Proteus ISIS program. An assembly program was written for the PIC so as. when S1 is put on the motor rotates right and if S2 is put on the motor rotates left, and if neither of them is put on the motor stops. The (.hex) file was loaded to the PIC18f4550 family microcontroller found in the Proteus ISIS program and then the circuit simulated.

In the schematic below in figure 3.1 below, a power interface was placed between the microcontroller (a sequential circuit) and a stepper motor. The motor coils were connected with center-tapped windings to a 12V power supply. The stepper motor was optoisolated from the microcontroller unit with great caution, to&nbsp.protect it from signal noises [6]. The transistor (2N2222A) assisted in driving enough current in 4N37 led through 1kΩ resistor.&nbsp.

The stepper motor power was given through 12V power supplied via the TIP121 transistor. The diode on the stepper motor coil was used to prevent inductive kicks that occur when the coil goes off.