Joined: 13 Jan 2009
Location: Galati, Romania
|Posted: Thu Jan 29, 2009 11:51 am Post subject: RC servo tutorials
|Servos are used in R/C cars and for operating valves in the industry.
There are two tipes of Servo Motors:DC and AC servos.
DC servos are the ones used in model cars, planes, boats etc.
They contain a circuit which creates a pulse. That pulse is varied through a potentiometer and feeded in the comparator.
The comparator does what it's name sugests.
It compares the signal created by the Internal Circuit and the one from the comand line and then rotates the motor, gear sistem and at last the potentiometer, until the two signals( from the astable circuit and from the comand line) are the same.
Servos are acurate devices which move only a specific amount for a given signal.
But if controlled by an MCU, I suggest powering from a diferent supply ( they draw in about 1000 mA) and the negative ends of the two circuits should be conected to provide a common refference point, thus an acurate control.