Jun 2010Optek Technology, Industrial Sensing & ControlRequest Info
CARROLLTON, Texas, June 22, 2010 — TT electronics Optek Technology has enhanced its long-distance reflective switch with adjustable sensitivity and simplified mounting to enable design engineers to meet a number of noncontact reflective object sensing application needs. Designed for assembly line and automation equipment applications, the OPB725A-18Z device uses an infrared LED and a logic output sensor in a reflective switch configuration, and it features a reflective sensing distance of up to 609.6 mm, depending upon the object.
It includes an externally accessible trimpot that allows customers to adjust the sensitivity of the device. It is shipped with two M18 × 1-mm plastic nuts to allow for easy mounting into an 18-mm hole. The switch is suitable for use in applications that require feedback on the presence or absence of an object, such as vending machines, mail sorters and conveyor belts.
It is tested to ensure detection of a 203.2 × 203.2-mm 90% diffuse reflective white card at a distance of 457.2 mm, with the sensitivity set to maximum (clockwise rotation) by the trimpot, which is accessible through a 4.3-mm-diameter hole in the sensor body.
Additional applications include assembly line and machine automation, equipment security, machine safety, and door and end-of-travel sensing.
The long-distance reflective switch features an 850-nm LED and is offered with 122-cm 26 AWG wires with mounting nuts. Power dissipation is 250 mW, maximum collector voltage is 30 V, and collector DC current is 50 mA. Operating temperature ranges from 0 to 50 °C.
While an object is in the reflective path of the switch, light from the LED is reflected back to the housing, irradiating the surface of the logic output sensor and causing the output negative-positive-negative transistor to turn on, providing a low (0.8-V maximum) output voltage when connected to the appropriate value pull-up resistor. When the infrared light from the LED is not reflected to the photologic sensor, the output transistor turns off, minimizing the IC(ON) current and providing a high (22-V minimum) output.