Without a return spring, holding power may be reduced, permitting higher peak pulse power during actuation. High Efficiency Maximum efficiency is assisted by use of a design which does not require a return spring. Use of a pick and hold circuit, or pulsed operation with a bistable solenoid help to achieve maximum efficiency. The proportional Rotary Solenoid produces a torque proportional to the energisation current. This torque is approximately constant throughout the operating stroke.
Controlled force can be useful for control of gripping devices when handling fragile objects.
A conventional solenoid characteristic shows sharply increasing force as the solenoid closes, this is liable to crush fragile parts. Controlled torque actuation can be used for regulating tension in filament or web-handling applications, or for controlled speed operation of components such as optical shutters. In this configuration the displacement will be proportional to current. These parts produce higher work per unit volume than other types of rotary solenoid. The large range of movement and controlled torquemake the Proportional Rotary Solenoid a good replacement to pneumatic rotary actuators in many applications.