Product Name: Simulated Siren

Product Number: KX211

Package: Packaging Bag

Product size: 10*7.8*6.5cm

Packing Quantity: 360 PCS

Box Size: 60*40*55 CM

Device for simulating a police siren
LED, also known as light-emitting diodes, are made from compounds of gallium (Ga), arsenic (As), and phosphorus (P). They are currently widely used in energy-saving light bulbs, street lamps, office equipment, and electronic products. LED energy-saving lamps use high-brightness, flat-top white light-emitting LEDs as light sources, which have the advantages of high luminous efficiency, low power consumption, long life, and greenness. They are the ideal cold light source for future lighting and are expected to become the main lighting source for homes in the future.
 LED energy-saving lamps are caused by the field emission of light, which belongs to a cold light source. The light is soft, has good color rendering, low heat generation, low temperature, and has a service life of over 100,000 hours, which is dozens of times that of ordinary incandescent bulbs. They are generally not damaged.

Experimental Cognition
Battery box: As the name suggests, it is a box used to install and fix the batteries, which is a device for outputting battery power.
LED lights: LED stands for Light Emitting Diode, which is a solid-state semiconductor device that can directly convert electricity into light. The heart of an LED is a semiconductor wafer, with one end attached to a substrate and the other end connected to the positive terminal of the power source, enclosing the entire wafer in an epoxy resin. The semiconductor wafer consists of three parts: one is a P-type semiconductor, where holes dominate, and the other end is an N-type semiconductor, where electrons predominate. Typically, there is one to five quantum wells in the middle. When an electric current flows through the wire to act on the wafer, electrons and holes are pushed towards the quantum wells, where they recombine. This results in the emission of energy in the form of photons, which is the principle of LED light emission. The wavelength of the light, which is the color of the light, is determined by the material that forms the P-N junction.
Triode: When the triode operates in the amplification region, the collector current and the base current are essentially in a fixed ratio. The so-called amplification function of the triode is actually based on this fixed ratio, allowing a small current (the base current) to control a larger current (the collector current).
Resistance: The resistance of a conductor to the flow of current is called resistance! Factors affecting the size of resistance: length, cross-sectional area, material, temperature, and so on. Generally, for metal materials, resistance increases with temperature.
IC: is a specialized control IC for single-cell battery operation, which integrates two circuits: charging control and driving control. The charging control circuit includes level detection, charging control, and anti-backflow of battery current functions. The driving control circuit can complete level detection of rechargeable batteries (hereinafter referred to as batteries), generate pulse waves, manual standby, and high peak current limitation functions. This circuit can form a step-up type switch power supply system with only one peripheral inductor component, and the charging and driving efficiency are both over 80%. The circuit has high efficiency, low power consumption, a working voltage as low as 0.85V, and can automatically complete charging and driving functions. It is particularly suitable for lighting schemes powered by single-cell batteries.

Experimental steps:
1. Experiment preparation: Understand the experimental equipment: screw hole plate, loudspeaker, IC, transistor, LED light, resistor, wire, screwdriver, slant-nose pliers.

Experiment Report:
Understanding the working principle of a simulated alarm and making one by yourself certainly gives a deeper understanding of how a simulated siren is created.

Science and technology models mainly refer to land, sea, and air models. Science and technology model activities integrate science and competition, manual and brain work, and are deeply loved by a wide range of teenagers. Its main role is also to cultivate and improve the comprehensive manual innovation skills and high-quality of teenagers. Therefore, in the new form of deepening reform and vigorously promoting quality education at the turn of the century, actively carrying out science and technology model activities is an effective measure to implement quality education in an all-round way.
Expand Horizons and Enrich Scientific Knowledge
Science and technology model activities are rich in knowledge. For example, in the process of making and sailing model ships, students can understand why ships float, how ships maintain stability, why propellers generate power, and how ships move quickly. If we go deeper, students will encounter radio remote control transmitting and receiving machines, or master the principles of force, density, gravity, pressure, magnetic field, ship construction, engine construction, and radio material selection. Many of these knowledge are not in the "textbook" and are often needed in life. This will inspire students to think about other scientific and technological knowledge that comes from animal inspiration. Can you dare to imagine and make a science and technology model? Some may think of the inspiration from insects such as dragonflies and planes, or from fish shapes such as torpedoes, and can make some simple airplane models.In this way, students will come into contact with a variety of knowledge in science and technology model activities, which supplements a lot of book knowledge and opens up their horizons. It also enriches their extracurricular life and allows them to learn more about scientific knowledge.
Cultivate logical and thinking abilities
The technology model activity requires all participants to have a dialectical, holistic, and rigorous scientific approach in their thinking methods." "Although the sparrow is small, it has all the essential organs." The tiny technology model is a scaled-down version of large, real vehicles, ships, and airplanes; it is an integrated whole, where even a small change can affect the whole.
A model airplane that competes in duration in the air must go through two stages: high-speed climb and low-speed glide. The adjustment for the climb stage mainly involves the adjustment of the pull force line and the angle of attack after the wing is twisted. The position of the center of gravity, the installation angle of the wing and the horizontal tail, and the directional rudder all have an impact on the flight attitude of the airplane during climb, but these changes directly affect the performance of the model during the gliding stage. Therefore, in the design and adjustment, it is necessary to consider these stages comprehensively, as they have different loading conditions and solutions. For example, in the design and production of car, ship, and airplane models, the selection of materials for strength, rigidity, and weight is very serious. It is necessary to choose one of the best schemes from both. Therefore, in the scientific model activity, the thinking method requires adolescents to have a dialectical, holistic, and scientific approach. Otherwise, a small mistake can make the performance of the scientific model worse or even lead to failure.
It can be seen that the initial thinking of people begins with actions. The thinking characteristics of students are mainly in the form of concrete image thinking, and thinking cannot be separated from images and actions. In the process of operation activities, students need to move their eyes, move their hands, and think with their brains, speak with their mouths, so that the external operation process and the internal intellectual activities of dialectical, holistic, scientific, etc. are organically combined, which has effectively promoted their thinking development.
Three Cultivate Good Habits
Science and technology model activities are beneficial for shaping students' good personalities, cultivating their strong willpower and spirit of innovation, as well as their attention to detail and patience, forming a rigorous scientific attitude in doing things.
1. Scientific scheduling of time. Students face homework and various interests, talent cultivation, all need a certain amount of time and energy. Students must scientifically and reasonably arrange their time to achieve order and efficiency, without being overwhelmed.
2, having a beginning and an end. Nowadays, most students are only children, afraid of suffering and lack of perseverance, often give up halfway. If they choose activities that require them to use their hands and brains, let them try their best to complete a science and technology model work, their interest will rise again, because they all love to play with dynamic toys. From this perspective, it will also make them gradually overcome the laziness in the process of making, and persist in completing their own masterpieces. Thus, it also cultivates their habit of having a beginning and an end.
3, Collective Spirit. Students work together to design, create, and compete, helping, comparing, and learning from each other. This fosters a collective spirit among students, making them consider others and learn how to get along with others. In the socialist market economy, this collective spirit is essential for working together with others to create great achievements. The era of isolating themselves to boil pitch like Marie and Pierre Curie is no longer. Now, the society needs the cooperation of talent groups like the Apollo Moon Landing Project to transform the world and create the future.
Four: Stimulate students' interest in exploring the field of science and technology
A scientist or inventor, without a doubt, develops a profound interest in the things they love, and then explores and studies them, eventually achieving significant results in that field. Now, by having students create and assemble technology models, we allow them to understand the formation of power, the generation of buoyancy, and the effects of magnetic fields, laying a solid foundation for their future research and exploration in this area. This also sows the seeds of success.
In conclusion: actively developing science and technology model activities is an effective measure to implement quality education in schools, cultivate students' comprehensive development in morality, intelligence, physical, beauty, and labor, and improve their comprehensive quality. It is also an effective measure to implement the spirit of the opinions on strengthening popular science work issued by the Central Committee of the Communist Party of China and the State Council, as well as the National Fitness Program, and to fully implement the "Science and Education Revitalize the Country" strategy proposed by the Party's 15th National Congress.