Considering and analyzing the characteristics of street lamp lighting in urban residential areas, thermostatic element a new light-time controller for street lamp circuit is further designed and developed.
Among them, the main components of the photoelectric circuit include photoresistor and Schmidt flip-flop and so on, while the time-control circuit chooses to use capacitive charging delay circuit. Through the research and analysis of the circuit composition and working principle, the feasibility of the design is verified on the basis of circuit simulation. Based on this, the article takes the street lamp circuit of residential district as the key research content, and elaborates the specific design method of the light-time controller, hoping to be helpful. The energy saving method of street lamp lighting circuit is to effectively control the switching time of street lamp. At the present stage, there are relatively many types of street lamp circuit controller products, which are embodied in three aspects: light-controlled type, light-time dual-controlled type and time-controlled type. Among them, the light-controlled controller is difficult to achieve the goal of turning off the lights at midnight when the number of people is small, while the time-controlled controller is difficult to turn on the lights ahead of time in rainy and rainy weather conditions, nor can it delay turning on the lights under ideal weather conditions. For residential areas, street lights are required to turn on in the evening and turn off at midnight. Therefore, it is feasible to apply the light-time dual-control controller in the street lamp circuit of residential quarters. However, microprocessor and programmable logic controller are commonly used in street lamp circuit controller products. Although they have comprehensive functions, they require high cost and are difficult to design. Therefore, it is of practical significance to study and analyze the design of street light time controller in residential district. According to the content of Fig. 1, when switch and 1 are on, it can meet the requirement of light control that lights are turned on in the evening and turned off at daybreak. When the switch and 2 are on, it can satisfy the need of double control when the light is turned on in the evening and turned off at midnight. According to the content of figure 2, it can be seen that the main components of DC regulated power supply are capacitor filter, regulator regulator regulator circuit and Single-Phase Full-Wave rectifier. The optical control circuit is composed of voltage dividing circuit and Schmidt flip-flop.
The main components of voltage dividing circuit are photosensitive resistance R3 and resistance R2, while the main components of Schmidt flip-flop are resistance R4, R5 and CMOS in-phase buffer G1. By using the hysteresis characteristic of Schmidt flip-flop reasonably, the anti-jamming ability of optical control circuit can be improved continuously [1].
In addition, the composition of time-controlled circuit mainly includes capacitor G3, diode VD3, resistance R6-R8 and CMOS in-phase buffer G2. Its delay time is designed to be three blocks, which need switching S1 effectively.
On this basis, the components of the driving circuit are embodied in switch S2, resistance R9, dry spring relay RR and transistor VT. In Figure 2, if the switch S2 is adjusted to 1 position, it can play the function of light control. In the case of strong daylight conditions, R3 always presents in a low resistance state, while the potential of point a is smaller than the forward threshold voltage of Schmidt flip-flop, and point B is low. At the same time, the transistor VT is in the cut-off state, at which time the dry spring relay RR will not operate. When it is in the late afternoon, the light condition is relatively weak, then R3 will show a high resistance state, and the potential of point a will increase accordingly. When the potential of point a is relatively higher than the forward threshold voltage of Schmidt flip-flop, the potential of point B will flip over and turn to a high level. At this time, the transistor VT is on-state, while the reed relay RR will operate. In this way, the RR contacts of the reed relay drive the actuators to achieve the goal of power transmission for the street lamp line [2]. The next morning, the light will gradually become stronger, so that point a potential will again appear lower than the forward threshold voltage of Schmidt flip-flop, and point B will flip over and turn to a low level. At this time, the transistor VT is in the cut-off state. At this time, the dry spring relay RR will return, and the executing element will return to the street lamp circuit. Power cut off.
For capacitor C2, its main function is to absorb instantaneous bright light interference. In Figure 2, if the switch S2 is adjusted to the position of 2, it can play the function of double control of light-time. In the case of strong daylight conditions, R3 always presents in a low resistance state, while the potential of point a is smaller than the forward threshold voltage of Schmidt flip-flop.
Points b, C and D are all low. At the same time, the transistor VT is in the cut-off state, at which time the dry spring relay RR will not operate. In the late afternoon, when the light condition is relatively weak, R3 will show a high resistance state. When the potential of point a is relatively high compared with the forward threshold voltage of Schmidt flip-flop, the potential of point b, C and D is high. At this time, the dry spring relay RR will operate. In this way, the RR contacts of the reed relay drive the actuators to achieve the goal of power transmission for the street lamp line [3]. In this state, the capacitor C3 will start charging, so that the potential of point C will be reduced. At midnight, the potential opportunity will reach the threshold voltage of CMOS buffer. In this way, point D will flip and turn to low level. At this time, the transistor VT will be cut off, the reed relay RR will return, and the executive component will return to the street lamp. The power of the line is cut off. In the morning of the next day, the light will gradually increase, so that point a potential will again appear lower than the forward threshold voltage of Schmidt flip-flop, while point B will flip over and turn to a low level. At the same time, capacitor C3 will discharge immediately under the action of diode VD3, providing the necessary pre-supply for the next evening street lamp line. Ensuring security. Fig. 3 is the application circuit in which the AC contactor KM is used as the actuator.
Among them, the switch Q is usually used as an isolated power supply in the process of maintenance and installation, while the fuse FU function is short circuit protection. In addition, RR is the dynamic contact of the dry spring relay in the controller, which can control the power-on and power-off of the AC contactor coil, and achieve the goal of effective control of the street lamp lighting circuit. However, it should be noted that in the actual installation process, photoresistors need to be placed in the natural light environment where the light can not be directly illuminated and the rain and snow can be sheltered.
This kind of controller has been applied in a residential area. Because the original street lamp does not have the function of light control, the microprocessor controller of power supply time and power cut time can be adjusted automatically according to the difference of longitude and latitude, so it can not adjust the power supply time and power cut time of street lamp line in combination with weather conditions. Through the application of the above light time controller, the transmission time and outage time of street lamp line can be adjusted according to the weather conditions. At the same time, the transmission time and outage time of street lamp line can also be adjusted according to the difference of saving. In this district, the application circuit of Figure 3 is chosen. One way is light control, while the other way is light-time double control.
It can ensure that most street lights are out after midnight, while only a few street lights near the gate of residential district and the main road are closed after daylight. After a long period of use, it was found that the actual effect was ideal, and the annual lighting power consumption of outdoor street lamps in residential areas was 30% lower than that of the original street lamps.