Originally Posted by
RomanLini
You need to separate the 2 currents to understand the operation. The motor current and power supply current are totally different things.
The chopper driver gives closed loop regulation of MOTOR current. The psu current will be less, because it is a switchmode system that provides voltage and current transformation; from psu = high voltage low current to motor = low voltage high current.
Because motor current is the one regulated, the psu current will change according to the needs of the entire system, ie more psu current is drawn during acceleration.