stepper motor

[SK0480]

Hello Iam controlling a stepper motor through a daq board's DIOs, now iam using a LM18293(push pull driver) to amplify currents to run the motor. This LM18293 outputs 1A current to the stepper motor phases. I need to know what other current amplifiers can I use to run my stepper motor besides this. Iam not doing anything sophisticated where I will need to use a motion contoller-Iam using a schools computers and it is not equipped with motion control.

[Greg_S-Video]

Hello SK0480

Thank you very much for choosing National Instruments.  Are you currently experiencing an issue such as a lack of performance with the LM18293?  There are likely a number of current amplifiers you could use with this device.  Are there any more parameters that would help you narrow down your search?  In addition, which DAQ board are you using control your current amplifier?  What is the model number of the motor(s) you are using?

Please let me know so I can further assist you with this matter.

[SK0480]

Well Iam just controlling a stepper motor using labview VI by applying  pulses, and using LM18293 to amplify the current from the DIO. Now I was looking at the datasheet of LM18293 it says that it outputs a maximum  1 amp of current to the motor. Iam not having any issue with this current amplifier.. I am using unipolar stepper motor because it is easier to connect to then bipolar because for that I will need to use H bridges meaning additional component. So Iam using unipolar motor, and I was looking at an example problem in the NI website that shows how to connect stepper motor with LM18293. What Iam confused on is this--since the maximum current comming out of this is 1AMP. Lets say if iam using a unipolar motor that requires more than 1AMP per phase then this obviously means that this amplifier is useless and wont be able to drive the motor--the question I have is what amplifer will I need to use if the motor requires more than 1 AMP per phase

[SK0480]

Iam using an NI ELVIS II, which has a built in DAQ

[Greg_S-Video]

Hello SK0480

Thank you very much for clarifying this issue.  If you are interested in achieving this functionality with National Instruments products, I highly recommend you look into our available motor drivers.  Please see the following link:

NI Drives

http://sine.ni.com/np/app/main/p/ap/motion/lang/en/pg/1/sn/n17:motion/fmid/112/#h13

There are literally numerous options for current amplification.  Perhaps the manufacturers of the LM18293 have a more substantial current amplifier.  The benefit of the NI Drives is that these are products we are most familiar with.

Please let me know how you would like to proceed and I will be sure to assist you.

[SK0480]

Well Iam not doing anything sophisticated where I would use the NI drives, my question was very simple and straightforward...

what kind of stepper motors can I use if iam using this LM12893 as a current amplifer..

[Greg_S-Video]

Hello SK0480

If a 1 AMP max current driver is your only design criteria, there are literally so many solutions.  Are there any other design criteria you can improse as to help narrow your search?  I would very much like to assist you with this.

Please let me know!

[Buechsenschuetz]

Usually it is not necessary to drive a motor with the full power rate. Virtually any stepper motor will run with a fraction of the rated current. I do not know whether motor manufacturers give minimum specs for current but I think virtually any motor rated up to 3A will run with 1A. Of course torque and power will be reduced, this is an issue mainly when driving heavy loads or running the motor at high step rates.