Hi all,
I previously posted a message here with regards to this problem but have been experimenting since and come up with some new results...
I have designed and built a Unipolar chopper drive for an a lead Bifilar wound stepper (4Amp 0.85Ohm 1mH approx). I have had good success running smaller motors but this one is giving me grief!!!
The current build up within the windings happens so quick that it seemed that I must of had duff sense resistors that seemed really inductive. This is not the case, it seems that because the motor is Bifilar wound it acts like a transformer. When the current builds up in the first coil the second coil releases its energy from the inductance through the freewheeling diode. This unfortuneatly seems to screw up the amount of useful continuos current in the windings - because it all happens too fast, the current builds up to about 4 amps in 2 micro seconds.
Can anyone give me some advice on what to do about this.
Mark Lewry
PS Thanks to all who previously helped
I previously posted a message here with regards to this problem but have been experimenting since and come up with some new results...
I have designed and built a Unipolar chopper drive for an a lead Bifilar wound stepper (4Amp 0.85Ohm 1mH approx). I have had good success running smaller motors but this one is giving me grief!!!
The current build up within the windings happens so quick that it seemed that I must of had duff sense resistors that seemed really inductive. This is not the case, it seems that because the motor is Bifilar wound it acts like a transformer. When the current builds up in the first coil the second coil releases its energy from the inductance through the freewheeling diode. This unfortuneatly seems to screw up the amount of useful continuos current in the windings - because it all happens too fast, the current builds up to about 4 amps in 2 micro seconds.
Can anyone give me some advice on what to do about this.
Mark Lewry
PS Thanks to all who previously helped