Telegraph Course Presentation

The principle of radio transmission is: when sending a message, the transmitter generates different frequencies and wavelengths of current according to the requirements of the message to be sent. This causes the electrons on the transmitting antenna to rotate continuously in different directions, causing the magnetic field lines to break off and pop out. The motion of the magnetic field lines attracts space free electrons, causing themselves to grow. This forms a spacing plane of different frequencies and wavelengths of "waves" in all directions of space. When this "wave" hits the radio receiving antenna, it drives the surface free electrons to spin around the antenna according to the frequency and wavelength of the "wave", forming a alternating current. This weak current is amplified, and it becomes the received information of the receiver.
This introduction to this small telegraph machine is a great example of a simple yet innovative technology project. The principle is very simple. Two dry batteries, a push button switch, a resistor, and an LED light are connected in series. When the button is pressed, the circuit is completed, and current flows through the LED light, making it glow, while the sound generator is powered up to produce a sound. When the button is released, the current disappears, and the telegraph message is completed. We know that telegraphy sends information by the length of the sound (or signal). Our small telegraph machine, by controlling the duration of the switch to control the interval of the sound, can distinguish long sounds from short ones, thus achieving the purpose of sending information.

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.

Switch: A device for turning on and off power supply.
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.
Speaker: It's a very simple principle. It uses a mouth to output square waves, and when these waves are input into a buzzer, it will produce sound. By controlling the frequency and duration of the square waves, it can also produce simple music.

Experimental steps:
1. Experiment preparation: Understand the experimental equipment: screw hole plate, switch, resistor, wire, LED light, battery box, speaker, screwdriver, and diagonal pliers.

Experiment Report:
The principle of radio technology lies in the fact that changes in the strength of current within conductors generate radio waves. By exploiting this phenomenon, information can be loaded onto radio waves through modulation. When the waves propagate through space and reach the receiving end, the changes in the electromagnetic field caused by the waves will generate currents in conductors. By demodulating the current changes, the information can be extracted, thereby achieving the purpose of information transmission.

Company Profile

 Chiluo Toy Factory was established in 2007. After ten years of unremitting efforts, our company has gradually matured; Our company is a member of the National Ministry of Education Teaching Equipment Industry Association and a backbone enterprise of Zhejiang Province Teaching Equipment. The company has been awarded the "Heavy Contract and Credit-Keeping" unit for three consecutive years by Yiwu City. In 2014, it was designated by the Zhejiang Provincial Education Bureau as the "Culture and Popularization Experiment Equipment Fixed-point Production Unit."

AiGou Company is a high-tech enterprise that integrates modern scientific research and development, educational equipment, curriculum design, teaching resource integration, and technical services. AiGou, with its high-tech products, is a professional enterprise in the development and production of popular science experiment teaching materials in the country. The products are exported to Europe and the United States.
 After years of accumulation, the company has initially reached a certain scale. In terms of technological innovation, the company has professional design personnel engaged in the development of scientific education products and the upgrade and replacement of existing products. In terms of production, management, and service, the company strictly implements the standards of the ISO9001 international quality assurance system. In marketing, the AiGou products have been entered into many provinces and cities in the country and enjoy a good reputation. For many years, it has provided high-quality, advanced, professional series of modern teaching equipment and professional equipment research and development custom services for the educational community. With excellent, high-quality professional talents and perfect after-sales service, it ensures the excellence of product quality and establishes a good corporate image. The scientific education physical series, chemical series, photovoltaic, wind energy, geography, biology, art and other products of Qiquan have successfully won bids in the education bureau tenders many times.

 Chilvog Company continues to adhere to the business philosophy of 'quality first, service to diligence, honesty in conduct', providing excellent equipment and high-quality service for school teaching and research. We are willing to work diligently with new and old friends at home and abroad, join hands to progress, and devote our utmost efforts to education, dedicated to the cause of education.

 ChiliBuy ensures that every child can keep up with the times!!!