Servo Motors In The Lab
Radio controlled automated robots use tiny servo motors that are positioned by converting the length of the pulse fed to them into the position of the output shaft of the servo. These servo motors consist of a motor, a gearbox and a small integrated circuit. The integrated circuit converts then length of the incoming pulse to the desired output shaft position as represented by the shaft-mounted potentiometer. If the position of the potentiometer does not match the desired shaft position, the motor is turned either forwards or backwards until the potentiometer reaches the desired position. The current to the motor is then turned off. The situation is monitored constantly so that the correction is taking place at all times.
The position accuracy achieved depends on the accuracy of the potentiometer and the accuracy of the length of the pulse received. A resolution of about one half of a degree can be achieved with most model aircraft servos. It usually only requires three wires to tun these servo motors. Since lab automated servo motors work on the principle of converting a known pulse width to a motor output shaft, these motors are relatively easy to use, if a source that can generate short pulses is created. This fortunately can be done quite easily with the small single chip micro-computers that are on the marked.
The position accuracy achieved depends on the accuracy of the potentiometer and the accuracy of the length of the pulse received. A resolution of about one half of a degree can be achieved with most model aircraft servos. It usually only requires three wires to tun these servo motors. Since lab automated servo motors work on the principle of converting a known pulse width to a motor output shaft, these motors are relatively easy to use, if a source that can generate short pulses is created. This fortunately can be done quite easily with the small single chip micro-computers that are on the marked.