Electrical hysteresis units have an extremely wide torque range. Since these units can be controlled remotely, they are ideal for test stand applications where varying torque is required. Since drag torque is minimal, these units offer the widest available torque range of any of the hysteresis products. Most applications involving powered hysteresis units are in test stand requirements.
Fast response: Torque is independent of slip speed. It is also directly proportional to coil current, making response time extremely quick.
Repeatability: Under identical operating conditions, the unit will be able to duplicate it's performance. This makes it ideal for many testing applications.
Smooth operation: Since the unit transmits torque via magnetic flux, the torque is smooth throughout its operating rpm range.
Long life: Since torque is transmitted via an electromagnetic field, there are no wearing parts involved in the normal operation of the unit (except for bearings and seals). This means extremely long life. Hysteresis units will outlast any other type of electromechanical unit.
How It Works
Engagement: When current/voltage is applied to the field, it creates an internal magnetic flux. That flux is then transferred into a hysteresis disk passing through the field. The hysteresis disk is attached to the brake shaft. A magnetic drag on the hysteresis disk allows for a constant drag, or eventual stoppage of the output shaft.
Disengagement: When current/voltage is removed from the brake, the hysteresis disk is free to turn, and no relative force is transmitted between either member; therefore the only torque seen between the input and the output is bearing drag.
Cycling: Cycling is achieved by turning the voltage/current to the coil on and off.