Stepper motor controller

joobloo237

I have a box of bipolar stepper motors that are marked for .9A, and I need a controller for them. What should I be looking for in a controller and where can I get one cheap? Is the .9A a requirement or would a 750mA controller work, just with less power.

kwinn

You also need to know the voltage of the stepper. If you operate it at the nominal rated voltage it would probably burn out a 750mA controller. For operating at .9A I would suggest using a controller rated for at least 1.2A.

joobloo237

The stepper motor is rated for .9A and 24VDC. Which controller should I get.

hover1

You could use:
http://www.parallax.com/Store/Accessories/MotorServoControllers/tabid/160/CategoryID/35/List/0/Level/a/ProductID/375/Default.aspx?SortField=ProductName%2CProductName
in "Single Motor Double Current" mode, but you would only be able to run one of your motors from this board.
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joobloo237 said...
The stepper motor is rated for .9A and 24VDC. Which controller should I get.

kwinn

There are a lot of stepper motor drivers available from the very simple ones that are not much more than drive transistors that you provide all the control signals to, up smart controllers where you tell it direction, speed, and acceleration. What type is best for you depends on the type of stepper motor you have and what you want to use it for.

hover1

You could start with this simple circuit:

http://forums.parallax.com/showthread.php?p=798556

The MOSFETS will handle 3 Amps @ 60 Volts

joobloo237 said...
The stepper motor is rated for .9A and 24VDC. Which controller should I get.

Prettybird

·I have a few steppers and driver chips from a lot sale. Here are a few data sheets you might find useful. Not into stepper motors. They eat too much power for battery robotics.

kwinn

Prettybird, stepper motor power consumption can be reduced by turning off power to the windings when not moving.

joobloo237, the circuit hover1 suggested work well and can use most general purpose transistors capable of handling the voltage and current of the motors.

Another trick with stepper motors is to briefly switch to a higher voltage for starting/accelerating the motor. Very easy to do with unipolar steppers.

NWUpgrades

kwinn, How do you turn off the power to the windings? I am currently working with several stepper motor ideas for my robotic arm. I have about 200 of them of various sizes and it would be a HUGE help if I could not have power to them unless needed. I am using a BS2 BoeBot board. I also will soon be implementing a BS2SX chip. Thanks.

kwinn

NWUpgrades wrote: »

kwinn, How do you turn off the power to the windings? I am currently working with several stepper motor ideas for my robotic arm. I have about 200 of them of various sizes and it would be a HUGE help if I could not have power to them unless needed. I am using a BS2 BoeBot board. I also will soon be implementing a BS2SX chip. Thanks.

The simplest method of turning power to the motor off is to have a high side driver between the positive supply and the center taps of the motor winding as shown in the attached block diagram. The “Hold” voltage and diode is optional and the hold voltage is lower than V+. This allows you to use a higher voltage to drive or accellerate the motor and a lower voltage to hold or drive it at lower currents.