Zahn Electronics manufactures:

Pure DC, 2 quadrant DC Motor Controls;

Pure DC, 4 quadrant DC Motor Controls;

Chopper (pulses), 2 quadrant Motor Controls;

Chopper (pulses), 4 quadrant Motor Controls.

Click on one of the three.

Pure DC 2 Quadrant (One Direction) Motor Controls (Servo Amplifier)

Pure DC 4 Quadrant (Both Directions) Motor Controls (Servo Amplifier)

Chopper Motor Controls (pulse output) (Servo Amplifier)