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This design was the basis for
classic drive designs and is still used on older systems with 5
lead motors, or very high voltage (24-30Vdc) motors. It allows
for full/half step operation with a dropping resistor between
the supply voltage and motor to limit the current. While the L/R
technique is simple and inexpensive, it is also inefficient due
to the large power losses from the dropping resistor.
A positive or negative going pulse
(or train of pulses) with a minimum pulsewidth of 15
microseconds is required to step the motor. The driver phase
outputs change state and the motor steps on the leading edge of
the input pulse. The maximum control pulse rate is limited by
motor performance. The M6R6 driver has jumper selectable
positive or negative pulse inputs.
The direction input is pulled up to
+5 Vdc through an internal 10K ohm resistor. When the Direction
Control is not connected or a Logic “1†level is applied, the
motor will step in the CLOCKWISE direction when the step control
pulses are applied to the Step Input. Similarly, when a Logic
“0†is applied the motor steps in the COUNTERCLOCKWISE
direction.The CCW separate input for Counterclockwise clocks is
jumper selectable for positive or negative pulse input. Pulses
applied to this step input cause the motor to step in the
counterclockwise direction.
The CCW separate input for
Counterclockwise clocks is jumper selectable for positive or
negative pulse input. Pulses applied to this step input cause
the motor to step in the counterclockwise direction.
The HS/FS SELECT input is used to
select either Half-Step or Full-Step operation. Half-step
operation is generally preferred because this mode provides
better resolution and reduces motor resonance. The motor steps
in increments of half the natural step angle, e.g. in 0.9 degree
steps for a 1.8 degree step motor. In full-step operation, the
motor steps in 1.8 degree steps.
The motor On/Off input is used to
turn off all four phases of the motor in applications where
holding torque is not required.
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