stepper motor

Hi, i have a unipolar stepper motor (STH-54D500, 1.3 A, 6.5 V) with 5 wires, without driver.
I know that if i want to connect it to an arduino uno card, i need an ULN2003A. But ULN2003 a has only 500 mA and my motor need 1.3A. What i can do/add to my system, and thank you.

Why can't you use the Arduino stepper library? This is the easiest way to do control it without a driver.

The ULN2003A is not strong enough for your motor, pick one that is stronger from the following list;

http://reprap.org/wiki/Stepper_motor_driver#Stepper_driver_chips

rcorr:
The ULN2003A is not strong enough for your motor, pick one that is stronger from the following list;

http://reprap.org/wiki/Stepper_motor_driver#Stepper_driver_chips

Thanks for your list, but i found only bipolar stepper driver chips. :frowning:

The Arduino microcontroller should probably replace the need for a driver chip.

Try the following code (file → examples → stepper → step_one_revolution)

/*
 Stepper Motor Control - one revolution

 This program drives a unipolar or bipolar stepper motor.
 The motor is attached to digital pins 8 - 11 of the Arduino.

 The motor should revolve one revolution in one direction, then
 one revolution in the other direction.


 Created 11 Mar. 2007
 Modified 30 Nov. 2009
 by Tom Igoe

 */

#include <Stepper.h>

const int stepsPerRevolution = 200;  // change this to fit the number of steps per revolution
// for your motor

// initialize the stepper library on pins 8 through 11:
Stepper myStepper(stepsPerRevolution, 8, 9, 10, 11);

void setup() {
  // set the speed at 60 rpm:
  myStepper.setSpeed(60);
  // initialize the serial port:
  Serial.begin(9600);
}

void loop() {
  // step one revolution  in one direction:
  Serial.println("clockwise");
  myStepper.step(stepsPerRevolution);
  delay(500);

  // step one revolution in the other direction:
  Serial.println("counterclockwise");
  myStepper.step(-stepsPerRevolution);
  delay(500);
}

If that doesn’t work due to voltage or amperage insuffiencies, I am unaware of any unipolar stepper drivers, so you would either have to make your own driver using transistors, or buy a motor shield for your Arduino. I recommend the Seeed motor shield V1.0 or 2.0.

cressmanj24:
Why can't you use the Arduino stepper library? This is the easiest way to do control it without a driver.

Sorry. But this is BullCrap that wrong and could easily lead a newbie to damage his Arduino.

You cannot drive any motor directly with an Arduino.

@kdjender,
I have not heard of any other unipolar driver apart from the ULN2003 - Google might know.

I wonder is it possible to convert your 5-wire motor into a 6-wire motor. Some of the "unipolar" motors are bipolar motors in disguise. The 6-wire motors have 3 wires for each coil - one at each end and one in the centre. A unipolar motor has the 2 centre wires connected. For bipolar use one just ignores the centre wires of a 6-wire motor. However it is essential that the the two centre wires are separate.

...R

Sorry. I misunderstood the function of motor shield and driver, which led me to think that with a low power motor, only Arduino was necessary. Thank you for correcting me.

cressmanj24:
Thank you for correcting me.

No problem. Everyone of us makes mistakes.
Best to limit advice to stuff you have actually done yourself.

...R

Here, this should be strong enough....

http://hades.mech.northwestern.edu/index.php/Unipolar_Stepper_Motor_Driver_Circuit

kdjender:
Hi, i have a unipolar stepper motor (STH-54D500, 1.3 A, 6.5 V) with 5 wires, without driver.
I know that if i want to connect it to an arduino uno card, i need an ULN2003A. But ULN2003 a has only 500 mA and my motor need 1.3A. What i can do/add to my system, and thank you.

The ULN2803 has 8 channels, you can double them up for twice the current
handling. Otherwise its the same as ULN2003.

4 logic-level n-channel MOSFETs will perform better, but cost more.