MOTION CONTROL
Compact Incremental Encoder Features Multiple Functions
Responding to industry demand for smaller components, Portescap (La-Chaux-de-Fonds, Switzerland) has introduced an incremental encoder measuring 22 mm diam. The encoder's photodiode matrix captures infrared light, which is modulated by the code wheel's rotation; the resulting differential measure is converted into logic signals with an electrical phase angle of 90°. This process, according to the manufacturer, minimizes thermal drift.
The three-channel encoder features output signals that are compatible with complementary metal-oxide semiconductor technology, which allows greater miniaturization of integrated circuits and enhances immunity to electromagnetic noise when compared with conventional techniques. The unit also has energy-saving current reduction in standby mode and the ability to detect rotation direction and signal transitions in the A and B channels, thus permitting direct access to a counter or microprocessor.
In order to ensure precise alignment, the unit's mask is incorporated into the integrated circuit positioned directly above the photodiode. Control of the diode current can also be integrated to guarantee constant light emissions and to avoid problems related to aging and temperature drift.
To enhance reliability, precision, and stability, components are interconnected via a tape-automated bonding process. The use of Kapton film facilitates the assembly of the integrated circuit, diode, and connector.
