Photoelectric switch application and precautions - Solutions - Huaqiang Electronic Network

Photocoupler

1. Input power supply voltage fluctuations should be considered when using DC input mode. Typically, the acceptable fluctuation range is ±10%. It's important to ensure that the power source remains stable to avoid unexpected behavior in the photoelectric switch. 2. Proper wiring is essential. Ensure cables are within the specified length and shielded against noise for better performance. For safety, keep high-voltage lines, power lines, and photoelectric sensor wiring separate. Placing them together may cause interference, leading to malfunctions or damage due to electromagnetic induction. Always follow the principle of separate wiring. 3. Response time is a key factor. Choose a photoelectric switch with sufficient response speed based on the size and movement speed of the object being detected. For through-beam types, consider the beam thickness as it affects detection accuracy. A pre-calculation of the entire beam path is recommended. 4. Sensitivity settings must account for environmental conditions. When using through-beam types in harsh environments, allow at least four times the set distance. For reflective types, leave 1.5–2 times the set distance for reliable operation. 5. Protection measures are crucial. Most DC-powered photoelectric switches include reverse polarity protection. Some models have overcurrent and short-circuit protection, either temporary or self-locking. In the case of self-locking, the output will stop until the system is reset. For contactless outputs, a freewheeling transistor is usually used. If high-power inductive loads are involved, an external surge absorption circuit is recommended. 6. Anti-vibration and impact resistance: While most photoelectric switches can tolerate vibrations up to 2000 beats per minute with a 2 mm amplitude, incandescent light sources require a more stable structure to prevent misoperation. 7. Interference from ambient light can affect performance. Infrared photoelectric switches typically resist up to 3,000 Lux from incandescent lights and 10,000 Lux from sunlight. Strong direct sunlight may still cause issues, so optical filters may not be enough. Special models are available for environments with over 100,000 Lux. Avoid direct exposure and adjust sensitivity accordingly. Use a visor or light-shielding tube if necessary. 8. To prevent mutual interference between multiple units, cross the transmitter and receiver or increase the spacing between groups. Using different frequency models is another option. Reflective types need proper separation based on their beam angle and detection distance. 9. The mirror effect can cause false triggers. If the object has a shiny surface, install the emitter and receiver at a 10–20° angle to avoid direct reflection. 10. Background effects can cause instability. Use a distance-limited setup, remove the background, or make it matte black. A rough, dark surface helps reduce unwanted reflections. 11. Self-diagnosis features help detect issues like misalignment, dust, or temperature changes. The STABILITY indicator alerts users to make adjustments before problems occur. 12. The countertop can reflect light back to the receiver. Keep the transmitter and receiver away from the surface and add a visor to prevent interference. 13. Regular maintenance of mirrors and reflectors is essential. Clean them gently without chemicals that could damage the lens or surface. 14. Temperature ranges vary by model, typically from -20°C to 55°C. Extreme temperatures may require cooling or heating solutions. Consult Teopto’s engineers for specific applications. 15. Calibrating the optical axis ensures accurate performance. Leave extra space for adjustment, use expandable optics, and ensure secure installation. Fine-tune and fix the alignment once set. 16. Signal-to-noise ratio (S/N) is critical. Maximize incoming light during detection and minimize it during shading for stable operation. 17. Avoid locations with excessive dust, corrosive gases, water, oil, or direct sunlight. Ensure the environment stays within the product’s operating temperature and vibration limits. These factors can lead to malfunctions. This guide covers general application practices. Consider material properties such as roughness, color, and transparency for optimal results.