Speed assembly with modular encoders
Dynamics Research Corp.'s new TK91 modular encoder provides position feedback for motion applications. Major advantage: quick and easy installation on the back of a motor. No need to power the encoder, use test equipment or measuring tools during installation. Disc line counts are available up to 1,250 lines per rev, with optional zero reference. Hub sizes up to 3/8 inch are available in either standard or metric units. Line driver and amplified analog are available in addition to standard quadrature TTL electrical output. Standard frequency response is 100 KHz at 70C with an option of 200 KHz at 85C.
Dynamics Research Corp.
Protect personnel and equipment with US-made devices
To provide OSHA-required self-monitoring protection for emergency stop circuits, Control Experts Inc. has developed two new safety relay modules. The safety master control relay module (Model MCSR101) has 4 voltage options: 120V ac, 240V ac, 24V dc, or 12V dc. The safety master control relay module with gate locking and monitoring (Model MCSGR201) is a 24V-dc gate-monitoring version. The device ensures that once the emergency stop is activated, the machine will not start until the fault is cleared and the reset button is pressed. Although made in the U.S., these devices meet strict U.S., Canadian, EU, and Japanese safety standards and are marketed worldwide. The modular concept incorporates three safety relays and circuit boards within a housing, and represents a significant advance over the previous method of using three separately winded relays.
Control Experts Inc.
Maintain speed control during acc and dec
Maxon's four-quadrant brushless-motor controller (4-Q-EC) provides electronic commutation and speed control for three-phase brushless dc motors. Its four-quadrant design maintains speed control during acceleration and braking in either direction. Supply voltage is 10-50V, with a 4V drop to the motor. Maximum continuous current is 6A using an additional heat sink. The controller measures 4.1 @ 2.8 inch and 1.5 inch high including connector. The unit is CE approved, and weighs 7.6 oz. Ambient temperature range is -40F to 185F for storage, and 14F to 113F for operation.
Maxon Precision Motors
Cut costs with motion chips
On top of the fundamental cost advantage, engineers that use motion processor chips may also achieve a more compact design with lower power consumption. The MC1241A uses a "sine-wave" drive method that individually controls each phase of the step motor using a microstepping waveform. Ideal for step-motor based applications that integrate the controller and the amplifier on a single PC card. The MC1241A card is available in one- or two-axis configurations. Pricing for the two-axis chipset is $85 (1,000) with encoder feedback and $59 (1,000) without encoder feedback. Also available is a chipset evaluation board that consists of an IBM AT (ISA-bus) board and software package. The board exercises the full range of chipset features and saves design time when using off-the-shelf motion control chips.
Performance Motion Devices
Buy only the functionality required
Using a 16-bit local I/O bus instead of an 8-bit one, and replacing one bi-directional FIFO with two single- directional FIFOs, Galil reduced both size and cost by 50% on the new DMC-1400 series motion controllers. 1400s are ideal where space and budget are limited. Offering the same performance and functionality for stepper or servo motors as Galil's other controllers, the 1400 provides uncommitted I/O, application program memory with multitasking, position and speed control, gearing or electronic CAM, inputs for two separate encoders, and symbolic variables and arrays. The single-axis controller is 32-bit microprocessor driven and comes in ISA, PC/104, or stand-alone/RS-232 formats. In single quantity, price is $595.
Galil Motion Control Inc.
Dispose of the tachometer
Model 5211V brushless servoamplifier's voltage-to-frequency converter generates an analog velocity feedback voltage from the motor's digital Hall-effect commutating signals. The technique also generates feedback from digital encoder signals and eliminates the separate motor-driven tachometer that ordinarily generates velocity feedback. This amplifier develops ±170V at ±10A peak, and ±5A continuously. Dimensions are 6.58 @ 3.83 @ 1.37 inch, and weight is 1 lb. The unit uses color LEDs for status indication, and is protected against overload, temperature, and supply voltage fluctuations. A current-sensing circuit provides an analog output voltage of ±6V at ±10A, for remote monitoring. Price is $363 (1-9).
Copley Controls Corp.
Increase torque to inertia ratio
A new line of 1.7-inch-diameter brushless dc motors from AMETEK Technical Motor Div. increases torque-to-inertia ratio and improves speed control. Designed for medical, robotic, pump, compressor, office equipment, fan, blower, machine tool, and other applications that require precise rotary motion, torque ranges from 5 oz inch/amp to 25 oz inch/amp. These motors provide rapid start/stop, and power output ranges from 0.03 hp to 0.16 hp. Overall lengths range from 1.7 inch to 3.4 inches. These eight-pole, 12-slot, three-phase motors are available in 12-, 24-, or 36V inputs.
AMETEK Technical Motors Div.
Control motion and logic with one servodrive
First in the Millenium family of products, Westamp's SP2k includes power electronics to drive a servomotor and control electronics for two or four motion axes. The digital positioning servodrive runs up to 16 programs and eight PLC programs for motion and machine control simultaneously on a preemptive system kernel. A 60-MHz, 32/64-bit floating point DSP enables bi-quad digital lowpass and notch filters, polynomial splinning between cam joints, on-the-fly trajectory manipulation, and S-curve velocity profiles. Available in four amperes to more than 50 amperes, the drives are matched with a line of motors that range from three lb-in to more than 300 lb-inch.