LEDs enable efficient automatic lighting control since their lifespan is unaffected by frequent switching. Simple systems include photo relays reacting to ambient light, acoustic sensors activated by noise, and motion sensors detecting movement through infrared or microwave technology. Each option has cost, accuracy, and use-specific advantages and limitations.
Human-Centric Lighting (HCL) mimics natural light variations throughout the day to enhance productivity, reduce errors, and improve health. It adjusts light output and color temperature based on specific programs. Two approaches exist: one mimics sunrise and sunset, and the other aligns with the workday. Implemented via tunable LED fixtures and controlled by protocols like DALI-2, HCL can use cloud or local systems, applicable in various environments.
Color temperature is the temperature at which a black body emits radiation matching a light source's spectrum. Higher color temperatures have more blue, lower have more red. Described as cool or warm shades, humans adapt to sunlight's spectrum. LEDs with higher color temperatures are cheaper but may disrupt biorhythms. Turnable White fixtures allow adjustment of light shade, offering flexibility for various environments and mimicking natural light changes.
Vision is formed by analyzing rods and cones in our eyes. Rods detect black-and-white, while cones perceive color. RGB LED lights mix red, green, and blue to create colors and are used in displays and lighting. White light from RGB LEDs can be inconsistent, so blue-based LEDs with phosphor are used for pure white. RGBW LEDs, combining white, are used for residential lighting. Specialized systems can use more colors.
Color rendering assesses how accurately colors appear under different light sources. CRI, used since 1965, rates fidelity on a scale up to 100 but ignores color vividness. The newer IES TM-30-20 standard evaluates both fidelity (Rf) and gamut (Rg) using 99 color samples, offering improved precision for selecting LED lighting in varied environments like retail, offices, and museums.
