The Thyristor Speed Controller is designed to control the speed of the DC Motor/Generator in both the open-loop and closed-loop modes of control.

The Thyristor Speed Controller module contains a thyristor single-phase bridge rectifier installed in a full-height EMS module. Speed control of the dc motor is achieved by varying the firing angle of the thyristors. In the open-loop mode of control, the firing angle is set manually using a potentiometer, while, in the closed-loop mode, it is set by a controller which compares the motor armature voltage to a voltage reference set by the user. The mode of control is selectable using a toggle switch. Other parameters that can be controlled using the Thyristor Speed Controller include ramp control, IR compensation, and current limit. These controls are accessible directly on the faceplate of the module.

Schematic symbols and their electrical interconnections are silk-screened on the faceplate of the module. Components are terminated by 4 mm color-coded safety sockets where student access is required.