What's The Difference Between Stepper Motors, Servo Motors, and RC Servos (part 3)
Continued from this article: What's The Difference Between Stepper Motors, Servo Motors, and RC Servos (part 2)
We know in a DC motor, the load affects the speed and current draw. For applications that the exact position of the motor must be known, a feedback device, like an encoder, MUST be used (not optional like a stepper motor).
In fact the control circuitry to perform good servoing of a DC motor is MUCH more complex than the circuitry that controls a stepper motor.
remote control (RC) Servos:
Often when we are talking about robots, the word "servo" really means an remote control (RC) servo motor. This remote control (RC) servo motor is a small box designed for use in hobby airplanes and cars.
Inside this RC motor is a complete servo system, including motor, gearbox, feedback device (pot), servo control circuitry, and drive circuit. It's really amazing that they can stick all of that in such a small box.
Remote control (RC) servos normally have 3 wires: +v, ground, control. The control signal of RC servo is a pulse that occurs at about 50hz. The width of the pulse determines the position of the servo motors output. As we can see, this would be pretty easy to control with a digital controller such as a Basic Stamp. Most will run on 5-6 volts and draw 100-500ma depending on size.
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Know more about: servo motors, servo drives.
These articles will be useful to you too: The difference between a DC motor and servo motor.
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