New to robotics. Controlling a servo?

So I need a servo to move 90 degrees, and I read somewhere that you connect the reference wire to something and make the signal 1.5ms and it will make the servo rotate 90 degrees. I need to know what that ';something'; is.New to robotics. Controlling a servo?
You are new to servos so let me try to sort out some ideas for you. A servo is a system that can move a load at a predetermined rate...a rate servo. The sort of thing that drives a radar aerial at an airport...going round and round irrespective of the wind load on the aerial. Another type of servo is the positional servo which will move from one position to another at a predetermined rate...sort of thing that moves machinery from one position to another.


The servo itself can be hydraulic, electric, or pneumatic. The hydraulic system will need a source of high pressure oil as the ';power'; supply. The electric servo needs electricity as its power supply and the pneumatic servo needs a supply of compressed air as its power supply.


My knowledge is in electric servos and there are 3 distinct types depending on the motor technology. There is the stepping or stepper motor. This type of motor moves a precise angle for a pulse of energy applied to it. The angle of movement is fixed for each motor type and the list of angles is endless. Slight disavantage of the stepper motor is that it's torque output is fixed and if it is stalled then althought energy is being put in at the front end no movement will come out of the motor. The true servo motor can be either AC or DC. Why true servo motor because servos are the high performance motor...the GTI of the motor world. There have to deliver high performance all the time and must not fail so their carefull application is important.


A Rate servo need to have a speed sensor attached to the motor so that the control system can see how fast the motor is rotating. The Positional servo needs to have the speed sensor and a rotary position sensor so that the control system can determine both speed and positional control.





So getting back to your question, I would think that your wire should go to a stepper motor control drive and the stepper motor connected to the drive. By closing your signal the correct number of times you will get the motor to turn 90 degrees.





Good luck