Stepper control with L298 and L297

[cosimo]

Posted on January 08, 2014 at 23:07

Hi to all, my name is Cosimo and I need help about stepper driver.

From an old printer I've get a bipolar stepper and now I'm trying to drive it with L298 and L297 configuration. Whitout the stepper the output of L298 are: 0V 12V 0V 12V. It's ok! But with the motor the output of L298 are: 6V 6V 6V 6V. Why this?

Testing the L297 output I've without the motor: pin 4 0V, pin 6 4.4V, pin 5 4.4V, pin 7 0V, pin 9 4.4V, pin 8 4.4V.

Testing the L297 output I've with the motor: pin 4 0V, pin 6 4.4V, pin 5 2.2V, pin 7 0V, pin 9 4.4V, pin 8 2.2V.

Thanks in advance.Cosimo #l298-l297

[cosimo]

Posted on January 11, 2014 at 23:11

solved! 6V are normal in stepper when the start condition is 0101 with 12V supply of stepper.. the problem was ground connection between boards (driver L297+L298 and PIC32 starter kit) and clock speed to high.. thanks to all.

[2010ee320]

Posted on February 20, 2014 at 16:21

I am an Electrical Engineering student. I just wanna ask whether is there any need to connect optoisolator with L298? Doesn't it has built in protection?

 I am using STM32F303 microcontroller with NXT lego motors. Specs of motors are:Stall current: 2AFree running current: 60mA

[Enrico Poli]

Posted on February 24, 2014 at 11:08

Hi,

Usually optoisolator are not required in this kind of applications. The L298 integrates thermal protection and the current ratings you indicated are within the safety ranges of the IC.Enrico