Power supply for Servo
The servo requires a DC supply of 4.8 V to 6 V. For a specific servo, its voltage rating is given as one of its specification by the manufacturer. The DC supply can be given through a battery or a regulator. The battery voltage must be closer to the operating voltage of the servo. This will reduce the wastage of power as thermal radiation. A switched regulator can be used as the supply for better power efficiency. Learn more about working of a servo motor through exclusive images at the Insight about servo motor.
Selection of a Servo
The typical specifications of servo motors are torque, speed, weight, dimensions, motor type and bearing type. The motor type can be of 3 poles or 5 poles. The pole refers to the permanent magnets that are attached with the electromagnets. 5 pole servos are better than 3 pole motor because they provide better torque.
The servos are manufactured with different torque and speed ratings. The torque is the force applied by the motor to drive the servo arm. Speed is the measure that gives the estimate that how fast the servo attains a position. A manufacturer may compromise torque over speed or speed over torque in different models. The servos with better torque must be preferred.
The weight and dimensions are directly proportional to the torque. Obviously, the servo having more torque will also have larger dimensions and weight. The selection of a servo can be made according to the torque and speed requirements of the application. The weight and dimension may also play a vital role in optimizing the selection such as when a servo is needed for making an RC airplane or helicopter.
The website of the manufacturers can be seen to obtain details about different models of the servos. Also their product catalogue can be referred to. Some manufacturers like Futaba also provide online calculator for the selection of a servo.