I'm using IHMOA03 to control NEMA23 format stepper motor running in half-step current controlled clock step mode. I put the scope on the sense resistor R1 to monitor the phase current and it is not what I expected.
The motor is a six wire connection with the centre taps left unconnected: series full coil connection.
The pulse rate is circa 1kHz and vertical scale is 0.2V/div ( R1 is 0R1 ) . The wave is smoothed because R/L corresponds to about 625Hz ( 1 ohm / 1.6mH ) that's fine but I was expecting a symmetric waveform not this abrupt cut off.
Each winding should go through a cycle 0 70 100 70 0 -70 -100 -70 0 % ; ie a symmetrical cycle. Why am I not seeing this?
Slower speeds show the step nature but there is still this asymmetric switching. What is this about?