Digital I/O

[DorianM]

Hello,

For my project, I use a NI 6008 board, a G540 (gecko driver) and 3 stepper motors.

I've wrote a simple labview code which sends a "pulse train" to the digital output. When I test it I have 5 volt pics. But, when I plug the gecko driver and the stepper motor, I have only 1.5 volt pics, so my stepper motor can't move.

How can I solve this problem?

Thanks in advance.

Dorian

[SnowMule]

The digital outputs can't pump out enough current to drive a stepper.

You need a driver circuit between the stepper and the DO lines.

A ULN2003A chip will probably work; depending on the current of the stepper coils. 

5V to the stepper coils, other side into the driver, driver to DO, and drop the line low to "turn on" that coil.

[DorianM]

Thank you for your response. 

[apok]

the uln's do not have enough current source to drive a motor, use a mosfet or ssr..they have higher amp ratings.

[apok]