CUI Inc – AMT31: Commutation Encoder Reduces Assembly Time for BLDC Motors

CUI Inc has introduced the AMT31, a new series of modular encoders which generate standard U/V/W commutation signals for vectoring current to Brushless DC (BLDC) motors.

The AMT31 series measures the rotation, or angular displacement, of a rotor using CUI’s patented, capacitive code-generation system coupled with a proprietary ASIC. This technology achieves exceptional accuracy of ±12 arc min (±0.2°).

The AMT31’s contactless, capacitive technology means that the encoder can operate reliably in applications subject to vibration and contaminants, such as dust, dirt and oil, that commonly stop optical encoders from working effectively.

The AMT31 series incorporates a One Touch Zero™ feature, allowing for significant time saving during motor installation. Installing an optical encoder or hall sensors on a BLDC motor can be an iterative and time-consuming process, as the assembly must be precisely aligned with the correct motor windings. Once aligned, the assembly must then be checked, through the measurement of back EMF, to ensure it has been mounted accurately. This process can take more than 15 minutes per motor. The One Touch Zero feature in the AMT31 series dramatically simplifies this activity and reduces the duration of this process to a few seconds, saving time and cost during assembly.

The commutation output of the AMT31 can accommodate brushless motors with 2, 4, 6, 8, 10, 12 or 20 pole pairs, selectable at the factory or via CUI’s AMT Viewpoint™ graphical user interface. The AMT31 also offers supplementary incremental A, B and Z channels for various servo positioning and start-up sequences.

The resolution of the AMT31 is programmable in a range from 48 to 4,096 pulses per revolution. The devices measure 28.58 x 37.25 x 10.34mm.

Drawing just 10mA at 5V, the AMT31 series is ideally suited to mobile and battery-driven equipment.

• Operating temperature range: -40°C to +105°C
• Standard input voltage range: 4.5V to 5.5V DC
• Choice of radial or axial connector orientation
• Mating sleeve-width range: 2 to 8mm
• Multiple mounting-hole patterns
• Built-in diagnostics
• BLDC motors