Stepper Motors

CDA's stepper motors provide an incremental step output depending on the excitation logic applied to the motor windings. These stepper motors provide high running torque capacity per unit weight and size. Their high performance and excellent stepping accuracy make these components ideal in open loop positioning systems, incremental rate control systems, or limited angle rotary switched. Samarium combalt rare earth magnets, high grade stainless steel construction, and class H225 insulation system assure rugged, reliable performance under the most severe operating conditions.

Description / Applications: Rotary Accelerometers (RA's) provide a DC output voltage in proportion to the rotary acceleration of the motor shaft. These permanent magnet devices require no excitation or input power. Ra's are ideal components to achieve a higher order servo stability performance characteristic. The acceleration signal may be used alone, or the voltage may be integrated to provide velocity plus acceleration information. Feedback can eliminate limited cycle oscillation in geared servo systems, and allow high forward loop gain through response shaping networks (PI or PID) in digital or analog signal processing networks. See Page 23 for a Functional Block Diagram or a Rotary Accelerometer in a Close Loop Servo Application.

RA’s may also be used in stepper motor applications, to determine the torque null “crossover” of the motor rotor during operation. This information is useful to determine optimum stepping pulse rate in high load inertia applications, or the stepper motor pulse rate may be dynamically controlled to step at the crossover point, allowing the motor to operate at the higher efficiency slew region of performance while maintaining step count. Since the permanent magnet RA provides a direct DC signal, the output may be used to determine step to step integrity of the stepper motor in critical pointing mechanisms where step integrity is paramount

The data included herein provides greater detail of the benefits and application information of RA’s in stepper and servo motor applications.

Imperial Units
Type Output Voltage Output Load Added Length Accelerometer
Diameter
Added Inertia Added Weight
V/100kRAD/sec² Ohms Inches Inches Oz-In-
sec²
Oz.
03ACC 0.60 50000 0.622 0.750 6.6 E-05 0.750

Metric Units
Type Output Voltage Output Load Added Length Accelerometer
Diameter
Added Inertia Added Weight
V/100kRAD/sec² Ohms mm mm kg-m² kg
03ACC 0.60 50000 15.8 19.1 4.6 E-07 0.021