Hi
I am a new user of stepper motors (bipolar) and I am trying to work with the L297 controller and the L298 driver. I am setting the the L297 in the two phases on mode.
The circuit I am ussing is the recommended in the Application Notes of SGS - Thompson.
I was able to manage the L297. It means I had get the outputs I was expecting from the controller, (in pines Inh1, Inh2, A, B, C and D while I move the clock manually) but I did not get the necessary voltage in the winding pins (2 - 3 and 13 - 14 of the L298).
The voltage I get between the ends of the same coil were, different of zero, but similiar between them, that means that never circulate any current through the windings.
As I place Control in High level, for Phase chopping, I thought the problem could be in the sensing current circuit. To avoid that problem, I connected the pins 13 and 14 of the L297 to Gnd and a pair of 14 ohms resistences instead of the windings and 20 Volts to the Supply Voltage (Pin 4 of L298), to be sure the curent wasn´t never higher than 2 A, but nothing change.
I had change several L298 chips, foresighting they were burned, but nothing changed.
I am sure I am making something wrong, but I don´t know what additional things can I do. I will appreciate very much any help.
Raul