Sensors LED lighting intelligent control

Automatic control switch LED lighting


Electromechanical sensors as signal acquisition and conversion device, the electrical and mechanical technology is quite mature, in recent years, MEMS (microelectromechanical systems) technology, sensor technology, the rise in turn to small, intelligent, multi-functional, low cost of the great strides forward. Light sensors, infrared sensors and other types of sensors can be formed with an intelligent LED lighting control systems, sensors will be collected to a variety of physical signals into electrical signals, via integrated circuit of the AD (modulus) converter , MCU (Micro Controller), DA (digital-analog) converter on the collected signals intelligence processing, to control the LED lighting on and off. Humans can take this set in the MCU on a variety of control requirements, control LED light switch time, brightness, color, colorful changes, so as to achieve energy saving targets. Composed of sensors and LED lighting system block diagram shown in Figure 1. The current integrated circuit manufacturing technology has to be AD, DA, MCU integration in a 5mm × 5mm or smaller package, not installed in the fixture and the total area is very convenient.


Combination lamps with LED light sensors


Power LED lights landscape is a highly intelligent and unattended road lighting, using wind, solar power generation, energy storage batteries, so the automatic management of energy is very important. Photosensitive sensor is ideal for the morning, Tian An (sunrise, sunset) when the illumination changes in the control circuit automatically switches to an electronic sensor. Figure 2 shows the appearance of a photosensitive sensor. Figure 3 is a sensitive photoresistor sensor board, it is very sensitive to bright light and shade. Figure 4 is the basic principle of photoelectric conversion chart. Light control LED lighting system works shown in Figure 1.


Light sensors according to the weather, time and regional shopping centers LED lighting automatic opening and closing. In bright daylight by reducing its output power to reduce power consumption, when compared with the use of fluorescent lamps, the shop area is 200m2 of convenience stores 53% of the maximum power consumption can be reduced. Life expectancy up to about 5 to 10 million hours. Under normal circumstances, LED lighting life of 40,000 hours or so; luminous color can be RGB (red, green and blue) and colorful way of changing, so shopping more colorful lights, the atmosphere is more active; and supporting the use of the original yellow fluorescent compared to the blue LED, supporting the use of red, green and blue phosphor purple LED color rendering even higher.


Combination of infrared sensors and LED lighting


Infrared sensor is detected by the infrared transmitter and body work. The main principle is: the body of the infrared emission around 10μm filter through the Fresnel lens to the enhanced pyroelectric elements gathered PIR (passive infrared) detectors, when people activities, the emission of infrared radiation will change the location, The device will lose its charge balance, the occurrence of the release of the pyroelectric effect of the charge out, infrared sensors will filter through the Fresnel lens, the change of infrared radiation energy into electrical signals, which thermoelectric conversion. Passive infrared detector in the detection area without the body moves, the infrared sensor senses only the background temperature, when the body into the detection zone, through the Fresnel lens, pyroelectric infrared sensor is sensitive to body temperature and background temperature difference, the signal is collected after the detection system already exists to compare the data to determine whether someone is really into the detection zone such as the infrared source.


Passive infrared sensor has three key components: Fresnel lens filters, pyroelectric infrared sensors and matching low noise amplifier. Fresnel lens has two effects: first, focus on the role, is about to pyroelectric infrared signal reflected in the PIR on: The second is the detection area is divided into a number of clear and dark areas, so that a moving object into the detection zone / one can to temperature changes in the form of a difference in the PIR on the pyroelectric infrared signal. General will be matched low noise amplifier, when the ambient temperature rises on the detector, especially close to the body's normal body temperature (37 ℃), the decreased sensitivity of the sensor, its gain to compensate by increasing their sensitivity. Output signal can be used to drive the electronic switch, the switch to achieve control of LED lighting circuit. Figure 5 is the appearance of infrared sensors, infrared sensors Figure 6 is the internal structure and internal circuit. Figure 7 is the infrared sensor with LED lighting, which is a standard E27 screw lamp lights, the scope of its power supply is AC180V-250V (50/60Hz), infrared sensor detection range is about 3m ~ 15m, the standard products IFS-Bulb 3W lamps of 80 lm, 5W lamps up to 140 lm. in the LED light source module embedded in the central part of the infrared sensor. Once the infrared sensor detects body temperature, LED light bulbs will be in the 50s to automatically open and close. Applicable to any kind of indoor applications, such as corridors, storage rooms, stairs and entrance hall.





And infrared sensors similar to the ultrasonic sensor automatically detects moving objects in recent years to get more applications. Ultrasonic sensors are using the Doppler principle, firing out through the crystal than the body can sense high-frequency ultrasound, generally the choice of 25 ~ 40kHz typical wave, then the control module detects the frequency of the reflected wave, if there is movement of objects within the region, frequency of the reflected wave will have minor fluctuations, the Doppler effect, in order to determine the illumination region moving objects, so as to achieve the purpose of control switch. Figure 8 is a combination of ultrasonic sensor and microprocessor applications.


Longitudinal ultrasonic oscillation, can be in gas, liquid and solid communication, and its spread at different rates; it also has the phenomenon of refraction and reflection, airborne low frequency decreases rapidly, and in the solid, liquid, the attenuation small, distant spread. Ultrasonic sensors is the use of ultrasound for these features. Ultrasonic sensors are sensitive range, without the visual blind spot, free from obstacles and interference characteristics, the technology has been in business and security to be used more than 25 years, has proven to be the detection of small objects in motion the most effective way. Therefore, the composition with the LED lighting system can be sensitive control switch.


Because ultrasonic sensors with high sensitivity, the air vibration, heating and refrigeration systems and ventilation space around the adjacent ultrasonic sensors will cause the movement of produce false triggering, so the need for timely calibration of ultrasonic sensors.


Temperature sensor made of LED lamps over-temperature protection


Temperature Sensor NTC (negative temperature coefficient) to do over-temperature protection LED lamps are widely used in relatively early. LED lamps, such as using high-power LED light source to be a multi-wing aluminum radiator, the indoor lighting LED lamps used in space itself is small, heat dissipation to the bottleneck is still one of the largest technology. LED lamp heat uncomfortable, then, will result in LED light source due to overheating and early failure. LED lighting is turned on the heat but also because of the rising hot air to the lamp automatically enrichment, affect the power of life (Figure 9). Therefore, in the design of LED lamps, aluminum radiator in the square near the LED light source close to an NTC, for real-time collection of temperature lamps, when the lamp cup aluminum radiator temperature can be automatically reduced by the current source circuit output current, the lamp temperature; when the lamp cup aluminum radiator temperature is restricted setting off automatically when the power LED to achieve over-temperature protection lamp, when the temperature drops, then the lights turn on automatically (Figure 10).


Conclusion


Because LED lighting is a complete electronic products, with the LED lamps structural diversification, application of magnification, LED lighting design with more creativity, innovation, there will be more sensors are used in LED lighting and combined lighting engineering systems go. A new era of intelligent LED lighting is coming, human life will increasingly bright light and comfortable.