Problem in Stepper Motor Power

[malik_ashter_mehdy]

Hi
We are making a project on solar tracking system and for rotation we are using stepper motor. The stepper is 6 wire unipolar. We are using ULN2003 IC. Everything is ok but the stepper rotates with very low power. Please suggest how can we increase the power. If any other IC you know which provides high current pleas tell us.

 

[Resqueline]

Maybe you could try to provide some more information about the stepper motor and the power supply..

 

[malik_ashter_mehdy]

12 V battery and PM-42 stepper.

 

[Resqueline]

Just for reference, so we don't have to do things twice; here's your thread about the same thing in another board
They try to address several issues but you seem to have a hard time sharing information.

Here's the spec' range for the (Minebea) motor afaik. Which version (P/M/S) do you have?
Step angle: 3.6°~7.5°
NO. of phases: 2/4
Rated Voltage: 6.5V~24V
Rated Current: 0.17A~1.62A
Holding Torque: 420gcm~950gcm

Can you measure the coil resistance, red to others? Can you measure the static voltage drop over the ULN while driving the motor, or what the motor gets?

The correct drive sequence seems to be always driving two coils at the same time: black+yellow, black+orange, brown+orange, brown+yellow. What's your sequence?
You can't run it using just two phases at a time like you say you do on the other board.

 

[malik_ashter_mehdy]

Sorry I was on tour during last three days. I am a beginner in stepper motor. You gave me very helpful information and guideline to work in a correct way. I'll check all these specs and ask you if I have any problem.

 

[trueblue]

As a beginner in learning about stepper motors it is very important to know what you are up against. This website, http://anaheimautomation.com/manuals/forms/stepper-motor-guide.php has useful information about stepper motors which may prove to be beneficial for your project.

 

[malik_ashter_mehdy]

Thanks to both if you. My problem is solved now. Thanks for your cooperation.