A light curtain is an advanced method to protect personnel while working nearby a hazardous machine. This method is friendlier than conventional methods, like mechanical blocking. The light curtain system comprises infrared emitters and receptors, & control and logic circuitry. Besides, a feedback to the hazardous machine is deployed as well. This way, whenever personnel in the vicinity of the machine is prone to any hazard, the system shuts down the machine. Light curtain sensors are very efficient and are reliable as well.
How do they work?
A light curtain system comprises an array of infrared(IR) LEDs and IR-detectors. The LEDs are synchronized to produce pulses of infrared rays between intervals. They are programmed in such a way that one LED is electrically stimulated after another. Similarly, the detectors in the receiving unit are designed to detect pulses only at distinct intervals. The light curtain system is also coupled with the machine so that at any event that fails the logic, the machine is shut down.
When an opaque object crosses the array of LEDs, it interrupts one or more beams. The detectors programmed to detect pulses at distinct intervals misses the pulse once an object crosses the array. Then, the logic circuit sends a stop signal to the machine to turn it off.
Unlike conventional safety methods, the light curtain has a built-in system to monitor its functionality. Once any part of the system is failed, the control logic of the system stops the machine. It can be resumed only when the faulty component is replaced and a proper restart is facilitated.
Operation guarding is the primary application of light curtain sensors. It is widely used in industries that deal with hazardous machines. They are deployed at the zone of hazardous operations. Light curtains are mostly found in mechanical and hydraulic power presses, & molding presses.
Light Curtain Sensors
Modern light curtain sensors are very easy to install. They are shipped with everything programmed right into the core of the system. It is almost as easy as a plug and play system. The light curtain sensors, once deployed, are easy to maintain as well. Modern sensors have a compact design and have exceptional mechanical and electrical robustness. Their operating temperatures range from -10oC to 55oC. Their robust design also accommodates high resistance against dust and liquids as well.