122 DZE

1. Special Properties

The 122 DZE units of the 9591 series are speed controllers designed for DC shunt motors with separately excited fields. Field excitation must be supplied by the 9591 device itself. Motors with permanent magnets for field excitation cannot be operated with the 9591 controller.

The devices feature a compact design in Eurocard format (100 × 160 mm).

DC voltage is derived from the AC mains via a bridge rectifier circuit. This circuit supplies both the motor field and, via a downstream thyristor, the motor armature. The armature voltage can be continuously adjusted from zero up to 170 V using an external reference potentiometer. Control is achieved through phase-angle modulation of the rectified mains voltage.

To suppress mains feedback and protect against overvoltage, a choke is integrated into the mains input. This ensures high operational reliability even under adverse grid conditions.

The speed controllers are designed for single-quadrant operation of DC shunt motors. Using jumper J2, the braking function can be enabled or disabled.

Thanks to the use of a thyristor as the braking switch, the braking circuit is virtually wear-free.