Digital Motors

Analogue servos are really ingenious bits of hardware. But there’s an even better alternative: the digital servo! Based on the operation of the ‘normal’ servo we tell you what’s so much better about the latest digital ones.A servo is a combination of a dc, ac or brushless motor with a position detection circuit. In modelling and robotics, we usually find three-wire dc servos. Such a servo then consists of dc motor, a reduction gearbox and two mechanical ‘stops’ preventing the spindle from turning beyond extreme positions. Usually, the servo also contains a potentiometer that enables the position of the spindle to be communicated to a small piece of electronics. The circuit, then, is the link between the motor, the measured position and the real world.