Even electric motors in the harshest environments require feedback to ensure smooth speed control. Passenger trains and locomotives use encoders to know when to switch coils inside motors to control acceleration and deceleration. When reliable feedback is required in environments with extreme shock and vibration, dirt and high temperatures, NorthStar brand encoders rise to the challenge. Starting with the proven HSD44, NorthStar offers feedback solutions designed to survive including products sealed against dust, oil, grease, liquids and mud, built with rugged housings and high operating temperatures.