I have inherited a stepper motor design project from a colleague.
His original design used an ST L6228 and this worked perfectly lifting a 4Kg weight.
He then produced a new design using an Allegro A3983. This has some issues.
Firstly, the stepper motor is specified for 5 volts but he has accidentally used 12 volts in the second design. However, the current ( I trip ) is correctly limited to 340mA.
I have inserted a 1 ohm 1% resistor in the motor output line and measure around 320mA, but the motor will only lift 1Kg.
I have been through the Allegro specification sheet and all the guidelines seem to have been complied with.
Any suggestions please ?