Mohammad » Actuators http://robotics.reefat.com Robotics Blog Sun, 06 Jun 2010 21:40:10 +0000 en hourly 1 http://wordpress.org/?v=3.0.1 Stepper Motor Demo http://robotics.reefat.com/2008/08/stepper-motor-demo/ http://robotics.reefat.com/2008/08/stepper-motor-demo/#comments Thu, 14 Aug 2008 19:51:08 +0000 Mohammad http://robotics.reefat.com/?p=4 This is my first stepper motor project where the I have used NIPPON PF35T-48L4 unipolar motor which I controlled from a PC through the Parallel Port (LPT1, DB25). I simply used a ULN2003A IC which uses 7 Darlington Transistor Array to amplify the input current comming from the port. This 16-pin IC is capable to take TTL input and the output load may have high voltage upto 50V. I wrote small program in Visual Basic 6 using inpout32.dll driver.

Here is a screenshot for the unipolar stepper motor and the driver IC ULN2003A:

It is recommended to connect a 6.2V zener diode between the power supply and VDD (Pin 9) on the chip, to absorb reverse (or “back”) EMF from the magnetic field collapsing when motor coils are switched off.

To rotate the motor anti-clock wise, the step sequence sent to the parallel port is as follows:

STEP-1   0001     1
STEP-2   1001     9
STEP-3   1000     8
STEP-4   1010    10
STEP-5   0010     2
STEP-6   0110     6
STEP-7   0100     4
STEP-8   0101     5

Here is the live video of how the motor rotates:

]]> http://robotics.reefat.com/2008/08/stepper-motor-demo/feed/ 10