New multi-function control LED desk lamp

Recently, concerns about global resource shortages have heated up again. Let's not talk about the extent of global resource shortages. Take the situation in the author's area as an example. Many rural areas in our area have implemented a "power restriction" system since before the National Day, that is, electricity is supplied to rural areas for one day, and then the electricity is cut off for one day (about from 8 am to 7 pm). In addition, I learned from the news that there was a period of time when coal was not enough for power generation, and some areas even used oil for power generation, so the price of oil also rose very fast.

Another example is the shortage of water resources. According to a report on Xinhuanet on December 4, 2010: "As of now, the drought-affected area of ​​crops in the Huanghuai and Jianghuai winter wheat areas is 57.99 million mu (of which 6.27 million mu are severely drought-stricken and 300,000 mu are dry), and 1.77 million people and 1.55 million large livestock in some hilly areas in the north have difficulty in drinking water due to drought."

Therefore, saving resources is the main problem we will face in the future, and it also requires us to save resources at all times and in all places. In fact, people waste resources everywhere. A large classroom or a large teaching building is brightly lit, but there is no student inside, and the fan above is turning tirelessly. There are two reasons for this: people are too "lazy" and it is too "difficult" to save resources. In fact, the second point is also a major reason. For example, if the lighting, fans, air conditioners, etc. we use will automatically stop when no one is there, then saving resources will be much "easier". It is based on the second reason that we took the desk lamp as the experimental object and designed a new multi-functional control LED desk lamp. The innovation of this design is twofold: 1) Using LED lights to replace ordinary desk lamp tubes, which not only saves resources but also extends the service life of the desk lamp; second, the multi-functional control is not only suitable for controlling desk lamps, but also for controlling fans, air conditioners and other electrical equipment. The design concept is the same.

1 Functional features
The functional features of this design are as follows:
(1) Infrared control. This design adopts infrared automatic control. When we need light, but it is inconvenient to control or we are unwilling to control manual switches, our automatic control system plays an important role. When we come to the automatic control range of the desk lamp (0-1.2m), the infrared switch will be automatically activated and the lamp will automatically light up; once people leave, the infrared will automatically turn off the power. This saves energy and eliminates the need to repeatedly control the switch, making it more user-friendly. In addition, this product is used in a reasonable combination with ordinary switches and photoelectric switches based on infrared. If you approach the product without light (such as during the day), the photoelectric switch will automatically cut off the circuit. To ensure that the circuit is disconnected, the ordinary switch can also be disconnected so that the infrared cannot trigger the circuit, so the lamp will not light up.
(2) Automatic and manual adjustment of light intensity. This desk lamp is designed with a light adjustment function, and there are two adjustment methods: automatic adjustment using a photoresistor when the light intensity changes and manual adjustment using a micro-adjustable resistor. The two adjustment methods are cleverly used in the circuit to achieve the function of adjusting the light intensity in any change. In addition, the micro-adjustable resistor can also adjust the strongest light brightness to adapt to people in dark and bright environments to protect their eyes. It is also installed on the periphery for easy adjustment.
(3) Energy saving and environmental protection. This desk lamp is designed with LED lamps. LED is a cold light source. There are no loose parts in the lamp, and there is no filament burning or light decay. The service life is 60,000 to 100,000 hours, which can greatly reduce the maintenance cost of the lamp and avoid the pain of changing lamps. There is no ultraviolet and infrared light in the spectrum of LED, no heat, no radiation, and no mercury, lead and other elements that are harmful to the human body. The working voltage is low and it is safe to touch. In addition, energy saving is also important, because the power of LED is very low. 100 LED lamps are used in the design, and the full load power is only 3W, which is much lower than the power of ordinary desk lamps.

2 Circuit diagram design
This design uses the infrared approach principle. Infrared emits low and high potentials, thereby triggering the base of the transistor, making the transistor in the saturation and cutoff regions, so as to control the conduction and disconnection of the circuit. And it is equipped with a working indicator light, which can easily show the working status of the infrared. The infrared working principle diagram is shown in Figure 1.

In order to facilitate automatic control, we lengthened the control wire of automatic control, as shown in Figure 2.

The switch package is shown in Figure 3.

Based on the principle that the photoresistor has different resistance values ​​for different light, it is connected in series in the circuit to share the current flowing through the LED to control the power of the LED. The photoresistor is installed on the periphery to facilitate the collection of light and achieve the purpose of automatic light control. Using the characteristics of the fine-tuning resistor's sensitive resistance change, the brightness of the light can be adjusted by turning it clockwise or counterclockwise. It is installed on the periphery and is easy to adjust.
Finally, the actual picture and complete circuit diagram of this design are shown in the following three figures: