New and Notable Product Design

GEARBOX-BASED MULTI-TURN ENCODER

Danaher Industrial Controls Group Dynapar ACURO (http://rbi.ims.ca/4391-541).

The ACURO 36 uses a gearbox instead of a battery to provide multi-turn resolution. The mechanical gearbox has an installation height of 31 mm, lower than battery-buffered counter solutions. Gears eliminate the potential for a dead battery and the associated downtime required for maintenance. The 36-mm-diameter, hollow-shaft encoder operates at speeds of up to 12,000 rpm. Engineers used opto-ASIC electronics methodology to integrate functions and reduce the current draw to 45 mA for the single-turn version and 85 mA for the multi-turn design. Using the Bidirectional Synchronous Serial Interface (BiSS), a freely licensable, open-standard protocol with up to 10 Mbaud capability, the units deliver up to 12-bit multi-turn and 22-bit single-turn resolution.

ABSOLUTE INDUCTIVE ROTARY ENCODER

Heidenhain Corp. ECI/EQI 1100 Series (http://rbi.ims.ca/4391-542).

These rotary encoders use inductive scanning and EnDat (Encoder Data) bidirectional data transmission interface to provide positioning accuracy, speed stability, and control dynamics that exceed the performance of resolvers. The ECI 1116 is an absolute single-turn encoder with a resolution of 16-bit and the ECI 1128 encoder is an absolute multi-turn unit with 28-bit resolution. The units also provide an electronic ID label and diagnostic functions. With an outside diameter of 38 mm and a length of less than 28 mm, target applications include small servo drives and general applications with lower accuracy requirements.

INCREMENTAL LARGE BORE, HOLLOW-SHAFT ENCODER

BEI Technologies Inc. HS45 (http://rbi.ims.ca/4391-543).

Designed for large motor feedback applications, the HS45 optical encoder accepts motor shafts up to 1.625 inches in diameter (1.875 inches optional). Available in single- or dual-output versions, the dual version has electrically isolated outputs that can feed two different controllers from a single encoder. This technique provides speed and/or position synchronization without the cost of an additional encoder. The incremental output format has two channels with complements in quadrature, 1/2 cycle index gated with negative B channel. With a frequency response of 150 kHz, the cycles per shaft turn can be either 1,024 or 8,192. The units include protection for reverse voltage, overvoltage, and output short circuit.

SUB-MINI PHOTOELECTRIC SENSOR

Balluff Inc. BOS 2K (http://rbi.ims.ca/4391-544).

The 20-mm-long, 10-mm-high, 7.5-mm-wide photo sensor detects objects in tight quarters. Engineers took advantage of the high output of the newest light emitting diodes (LEDs) and focused the light to provide a laser-like (but not a laser) visible light beam for easy aiming and precise tracking. Units have a scan range of up to 1.2m for through beam, 3m for reflector, and 50 mm for diffuse (with white background) modes. In addition, units with background suppression ignore anything beyond the sensing distance to prevent false triggering and operate to either 15 or 30 mm regardless of the color.

USB-COMPATIBLE VIRTUAL ABSOLUTE ENCODER

Gurley Precision Instruments Model 7700 (http://rbi.ims.ca/4391-545).

Working directly with a laptop PC, these USB-compatible encoders get power from the USB port and provide input without requiring a proprietary protocol. The virtual absolute encoder has both cyclic and index tracks similar to an incremental encoder. However, instead of just a single line, the index track uses a serial code similar to a bar code. Consequently, no matter what the starting position or direction of travel, the initialization distance or angle is a fixed and very small motion increment. The position is absolute after 3.52 degrees of initial motion. Providing 18 bits or 262,144 measuring steps/revolution, the unit works with USB cables up to 5m (16 ft).

RUGGED HOLLOWSHAFT ENCODER

Turck T8.A02H (http://rbi.ims.ca/4391-554 ).

The T8.A02H is a heavy-duty incremental encoder for industry standard 3.5-inch, hollowshaft applications. To provide a highly rugged design, the disk table is mounted on the hub and the bearings are mechanically locked in place by a tolerance fit and a high temperature adhesive. Shoulders inside the housing provide a locking mechanism and a rubber lip seal keeps out dirt. The unit has shock capability of 2000 m/s² (6 ms) per DIN-IEC 68-2-27 and withstands vibration up to 100 m/s² (10-2000 Hz) per DIN-IEC 68-2-6. Designed for variable frequency drive AC motors with the industry standard 7272 line driver, the unit provides A-A, B-B, and Z-Z square wave outputs.