Snap-Trol Model 181 DC Motor Control

The Snap-Trol Model 181 series from Extron is a family of DC motor controls designed for adjustable-speed control of DC motors in industrial machinery. These drives regulate motor speed and torque and are used in applications such as paper processing equipment and conveyors.

The series spans numerous variants of the Model 181 DC drive, including configurations rated for approximately 1 HP. Individual models range across the 181-A through 181-Z designations, with select units offering higher power capability (up to 2 HP, 90/180 Vdc, 12 amp) and options such as dynamic braking (DB). The 181-Q is a representative 1 HP drive suited to controlling permanent magnet and shunt-wound DC motors through SCR-based phase control, typically from a single-phase AC input.