I finally got a stepper motor controller to work. The total time it took me to build this project was probably about 15-20 hours of trial and error over the course of the last two weeks. Note from circuit schematic: the final coil leads may not be in order. You will have to play around with the coils in order to make it fire in the right order.
Objective:
Make a 6-wire stepper motor turn.
Cost:
Around $40, mostly for the power supply and anything you have to buy from radioshack.
Method:
Utilize a 555 timer chip, to clock the 4017 counter. wire the counter so that only 4 leads count, by connecting the 4th output to reset.
The final parts list is:
1 555 timer chip
1 9 volt power supply, mine was rated for 800ma
1 4017 timer chips
1 5volt output voltage regulator I used 7805
1 stepper motor
4 NPN transistors, I used TIP120
5 1k Ohm resistors
1 100uF Capacitor
2 1uF Capacitors
What’s next:
Remake the circuit with a pic, or using ttl so that reverse is possible. It would also be cool to make a more efficient design. A more efficient design would fire two coils at a time. This makes more torque. Another option for smoother running is to approximate sin waves for the inputs to the motors. Each coil’s sin wav is slightly out of phase.
Finished Product with application
The goal is to have this whole motor controller in a nice looking box, using a 3 position toggle switch to go up and down or off, and make it turn my projector screen up or down.
