Electronic Design

Motors/Motion Control

Motor Drive Is 100-krad Tolerant And SEU Immune To 36 meV
The Space-520R, a member of the PWR-8250R Space Motor Drive series, is 100-krad tolerant and SEU immune to 36 meV. This device is intended to drive three-phase brushless dc motors. Rated at 100 V, the drive's available current ratings include 1, 3, and 10 A. As a self-contained, three-phase torque controller, the Space-520R contains command amplifiers, a pulse-width modulator (PWM), commutation control, a tachometer, a current sense amplifier, a gate drive, and a power MOSFET drive stage.

The Space-520R uses a four-quadrant complementary control technique that provides 3% current linearity and 5% current-regulating accuracy. Holding torque over the input range is maintained even at zero commanded input. The user can match the loop performance to the system and motor through the command amplifier's programmable gain and compensation features.

Operation with low inductance motors is enabled by the internal, adjustable PWM that can switch over the 10- to 100-kHz range. The three-phase drive is commutated from Hall sensors located in the motor. Additionally, the tachometer signal is derived from the Hall sensors. Optimized for radiation performance and noise immunity, the gate drive provides a controlled signal to the rad-hard MOSFET output stage. The device uses programmable power supplies to ensure minimal quiescent power.

The PWR-8250R1/R3 are available in a 41-pin plug-in or surface-mount package. The PWR-82520R10 comes in a 43-pin surface-mount package.

Pricing and availability information is available through the company.

DDC, 105 Wilbur Pl., Bohemia, NY 11716-2482; (631) 567-5600; fax (631) 567-7358; www.ddc-web.com.

Noncaptive Linear Actuator Reduces Motor Noise
The Size 23 noncaptive linear actuator guarantees high performance for more than 1 million cycles. The device features thermoplastics in the rotor drive nut and a stainless steel ACME lead screw. This design reduces motor noise and ensures maintenance-free operation.

A wide variety of resolutions are available, ranging from 0.0003125 to 0.001 in. Thrusts of up to 100 lbs. may be delivered without compromising long life and cost. According to the manufacturer, the actuator is ideal as a drop-in replacement to improve performance and lengthen life. Furthermore, the device is suited for applications requiring precise positioning and rapid motion.

In addition to standard configurations, the company can custom-design the motor to meet specific application requirements.

In 1000-unit quantities, the Size 23 linear actuator costs $100.

Haydon Switch & Instrument Inc., 1500 Meriden Rd., Waterbury, CT 06705; (800) 243-2715; fax (203) 756-8724; Internet: www.hsi-inc.com.

Standalone Motion Controller Maintains A 20-kHz Sampling Rate
As a standalone unit, the SB214SA provides up to four axes of motion control for ac induction, dc brush, and dc brushless motors. The device has a multiprocessor-distributed control design consisting of a 20-MHz Intel processor for high-level task management and one 80-MHz SB2500 servo processor per axis for real-time control tasks. Such a design maintains the integrity of the 20-kHz sampling rate regardless of the number of axes that are in use.

The controller communicates via an RS-232/422/485 serial connection at speeds up to 57,600 baud. Support of incremental encoders for primary and secondary feedback (master) is included. The device's I/O consists of dedicated safety inputs per axis, dedicated emergency stop, 16 isolated general-purpose inputs, 16 isolated general-purpose digital outputs, six analog inputs, and four analog outputs.

Programming common applications is simplified through built-in capabilities such as advanced pick-and-place, master/slave, and electronic gearing and camming. The device also includes a position event generator (PEG) function that generates real-time, position-triggered events with small electronic gate delays. Windows-based tools for setting up and tuning the modules are packaged with the motion controller. Also, the user can employ these tools to develop application programs.

Available now, the SB214SA costs $1995. OEM volume discounts are available.

ACS-Tech80 Inc., 658 Mendelssohn Ave. North, Minneapolis, MN 55427; (763) 542-9545; www.acs-tech80.com.

DMOS Outputs On PWM Motor Drivers Decrease Power Dissipation
The A3972/A3973 series of full-bridge microstepping pulse-width modulation (PWM) motors have n-channel DMOS outputs for decreased power dissipation. This design also provides higher peak-current capability compared to bipolar drivers. The A3972SB combines low-voltage CMOS logic, bipolar control circuits, and power DMOS transistors on a single chip.

Offering output currents up to ±1.5 A, this device also provides operating voltages to 50 V. Internal fixed off-time PWM current control timing circuitry can be programmed via a serial interface to operate in slow, fast, and mixed decay modes. A built-in 4-MHz oscillator allows for digital timing. Other features include a precision 2-V reference, inputs compatible with 3.3- or 5-V control signals, and "sleep" or "idle" modes. Thermal shutdown with hysteresis and crossover-current protection are also included.

According to the company, the devices suit stepper-motor applications in office automation, industrial controls, robotics, and medical equipment. The A3972 comes in a 24-lead "batwing" DIP package. Optionally, the A3973 comes in a 24-lead DIP and an SOIC package.

In 50,000-unit quantities, the A3972 costs $2.65. In similar quantities, the A3973 costs $2.15.

Allegro Microsystems Inc., 115 Northeast Cutoff, Box 15036, Worcester, MA 01615; (508) 853-5000; fax (508) 853-5049; www.allegromicro.com.

Motion Control Card Performs Accurately In Harsh Applications
The PCI-8134 four-axis motion control card is a PCI-based plug-in card that provides widely utilized pulse trains for both stepping and ac-dc servo motors. The device provides precise control of x-y tables, robotics, conveyers, pick-and-place equipment, electronic and semiconductor test equipment, material handlers, textile machinery, and palletizers.

The card features versatile trajectory planning. The user can program both acceleration and deceleration times. Also, the S-curve profile allows for smoother motion during starting and stopping. The PCI-8134 has hardware linear interpolation between two axes to reduce software computation efforts and increase control. For simple system integration, various operation modes are offered, including continuous motion, absolute move, relative move, manual pulsing, simultaneous move, speed change on-the-fly, linear interpolation, and home return.

The control card comes packaged with a full set of Windows DLLs for NT/98/95, C function libraries for DOS, and over 20 sample programs. Motion Creator, a Windows-based, graphical user interface utility software, also comes standard with the device.

Available now, the PCI-8134 costs $1250, or $999 each for ten-unit quantities. OEM and quantity discounts are available.

ADLINK Technology America Inc., 17951 Sky Park Cir., Bldg. 35, Ste. H, Irvine, CA 92614; (949) 250-3339; fax (949) 250-3336; www.adlinktechnology.com.

TAGS: Components
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