Nov 26 2008
Avago Technologies has announced that Physik Instrumente (PI), a German manufacturer of piezo ultrasonic drives, has selected its miniature AEDR-8320 high resolution reflective encoder for use in their M-664KCEP vertical drive used in bio-handling dispenser applications. The AEDR-8320 high-resolution surface mount (SMT) reflective optical encoder, which provides precise positioning information and direction sensing, is ideal for use in industrial automation applications where space is constrained. Avago is a leading supplier of analog interface components for communications, industrial and consumer applications.
PI markets its PILine® of piezo ultrasonic drives as an alternative to stackable motor concepts, especially in bio-handling dispenser applications where a compact high-speed actuator is needed. Typically, the accuracy for automation and handling tasks required for these actuators range from 5 to 100 µm. PI’s M-664KCEP is a cost effective vertical drive with PILine ultrasonic piezomotors. Lining up eight or more of these vertical drives allows the independent vertical movement of pipettes to fill micro titre plates. Matched with standard multiwell plates, the width of the individual actuator is only 9mm.
The M-664KCEP travels a distance of 50mm in 250 ms to generate a push/pull force of up to 4 N. The resolution of the positioning sensor of 5 µm is fine tuned to the application to ensure positioning accuracy. With dimensions of 6.50 mm length by 4.20 mm width by 1.69 mm height, and wide operating temperature range, Avago’s AEDR-8320 encoder was found to be an ideal fit for PI’s application.
“We selected Avago’s AEDR-8320 reflective encoder because it is a perfect match to all the advantages that ultrasonic piezomotors offer precision automation applications,” said Steffan Arnold, product manager, Physik Instrumente.
Avago’s AEDR-8320 series offers two channel analog output that provides a resolution of 180 lines per inch (LPI) for rotary and linear movement control. In addition, its two channel analog outputs can achieve even higher resolutions through interpolation. The AEDR-8320 can achieve resolutions of 2.2 µm to 10 µm for linear movement and from 4096 counts per revolution (CPR) to 7840 CPR for rotary sensing, utilizing an external interpolation IC. These high resolution optical encoders also incorporate an LED light source and photo detector IC in a single leadless package, and use reflective technology to sense rotary or linear position. Moreover, the AEDR-8320 encoder can be interfaced directly with most signal processing circuitries to provide design-in flexibility and easy integration into existing systems. Additionally, the AEDR-8320 series can be used with a reflective code wheel to sense rotary position and velocity, or with a linear code strip to sense linear position and velocity.