OT: Electronic question

A stepper motor is one that is typically used to move the shaft a precise number of degrees per 'step'. It is typically controlled by a pulse-drive mechanism (i.e., you don't just apply a voltage to it for it to work, there must be some form of control circuitry to apply the right number of pulses, of the right amplitude, at the right time). If you had a stepper motor that was one degree per step, for example, and you gave it the right number of pulses for 360 degrees, it would turn one full rotation. These motors are obviously used a lot in industry for precise motions (the last time I did any 'real' work with them was in the early nineties, on a medical laser program).

David Erbas-White

snipped-for-privacy@aol.com wrote:

Its what they use for CNC's. Generally some would modify a manual mill with stepper motor and a controller and make it CNC.

-- TAI FU

They are also used in common items, IE printers, CD players, DVD players, etc.

Ben

Unlike most types of motors, where you just apply power and the motor turns for as long as the power is applied, you apply pulses of power to stepper motors and they rotate a small distance (like one degree for pulse). They're used in applications where you want to be able to do a known rotation, without feedback. One of their really common applications has been in disk drives, where you can get a pulse to correspond to a track.

The implementation is a little bit more complex than this, but that's the basic idea.