A weight sensor, or load cell, uses strain gauges bonded to a bending beam. Their electrical resistance changes minutely when force is applied, stretching or compressing them. These gauges are arranged in a Wheatstone bridge circuit, producing a small voltage change. This signal is amplified and converted to a digital reading by an integrated circuit like the HX711, which a microcontroller can then interpret as a weight measurement.
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.
Automatic hallway lighting is designed to activate lights temporarily when a person is detected, and natural light is insufficient. A pyroelectric motion sensor or sound detection is used for presence detection. The BISS0001 chip controls the lighting, and components like resistors and capacitors set the light's activation duration. The circuit is powered by AC, using a full-wave bridge rectifier and solid-state relay to manage the light.
