|
The stepper motor driver
receives low-level signals from the indexer or control
system and converts them into electrical (step) pulses to
run the motor. One step pulse is required for every step of
the motor shaft. In full step mode, with a standard 200 step
motor, 200 step pulses are required to complete one
revolution. Likewise, in micro stepping mode the driver may
be required to generate 50,000 or more step pulses per
revolution.
In standard driver designs
this usually requires a lot of expensive circuitry. (AMS is
able to provide equal performance at low cost through a
technology developed at AMS known as VRMC®;
Variable Resolution Microstep Control).
Speed and torque
performance of the step motor is based on the flow of
current from the driver to the motor winding. The factor
that inhibits the flow, or limits the time it takes for the
current to energize the winding, is known as inductance. The
lower the inductance, the faster the current gets to the
winding and the better the performance of the motor. To
reduce inductance, most types of driver circuits are
designed to supply a greater amount of voltage than the
motors rated voltage. |
