At the end of 19, the discovery of Edison effect and the experiment to verify the existence of electromagnetic waves created conditions for the birth of electronics. 1895, the Italian g Marconi invented the wireless telegraph, which led to the emergence of wireless telephone and radio broadcasting. 1904, J.A. Fleming of England invented the diode electron tube. 1906, American L.D. forest invented the triode electron tube with amplification ability. After that, quadrupole, pentapole, more electron tubes and composite tubes came out one after another as the first generation of electronic devices. In the nearly half century before the invention of transistors, electron tubes played a very important role. 19 19, superheterodyne receiver came out, which created conditions for the development of radio. In the same year, the first radio station that regularly broadcasts language and music was built in Britain, and the following year, another radio station was built in Pittsburgh, USA. 1923 and 1924, American v.k. zworegin invented the camera tube and kinescope one after another; 193 1 year, he assembled the world's first all-electronic TV system. Around the end of 1930s, Britain and America began experimental TV broadcasting, and after World War II, TV broadcasting gradually became popular in various countries. 1954, the United States adopted the NTSC system and officially began color TV broadcasting. In 1963 and 1966, the Federal Republic of Germany and France have determined the compatible PAL and SECAM color TV formats respectively. 1898, the Danes invented the magnetic (steel wire) recorder; 1935, the German General Electric Company made the recorder; 1963, the Dutch Philips Company invented the cassette recorder. Since then, cassette tape recorders have been widely used.
The rise of electronic industry and plastic industry in 1950s promoted the rapid development of household appliances. The invention and application of transistor, especially the invention of integrated circuit, made electronic technology enter the era of microelectronics technology, achieved a leap and raised household appliances to a new level. In the 1970s, the advent of microcomputers promoted the development of household appliances to automation and intelligence, and a number of high-tech household appliances appeared one after another.
The classification scope of household appliances varies from country to country, and there is no unified classification of household appliances in the world. At present, there are two main ways to classify products, one is based on the function and use of products, and the other is based on the electrical working principle of products. The latter divides household appliances into four categories: refrigeration, electric heating, electrical appliances and electronic appliances, which are not perfect. It is common to classify products according to their functions and uses, but the specific classification methods vary from country to country and can be roughly divided into eight categories.
① Refrigeration appliance: also known as refrigeration appliance. Used for freezing and refrigerating articles (mainly food), including household refrigerators and cold drinks machines.
② Air-conditioning electrical appliances: referred to as air-conditioning electrical appliances. Used to adjust indoor air flow, temperature, humidity and remove dust in the air, including room air conditioner, electric fan, ventilator, cold and hot fan, air dehumidifier, etc.
③ Cleaning appliances: used for fabric cleaning and maintenance and indoor environment and equipment maintenance, including washing machines, dryers, electric irons, vacuum cleaners, floor polishers, etc.
④ Kitchen appliances: used for food preparation, cooking and kitchen sanitation, including electric cookers, microwave ovens, induction cookers, electric ovens, electric cookers, dishwashers, electric water heaters, food processors, etc.
⑤ Electric heater: used for household heating, including electric blanket (pad), electric quilt, electric clothes, heater, etc.
⑥ Beauty care appliances: used for hairdressing, facial cleaning and family medical care, including electric shaver, hair dryer, hair clipper, ultrasonic face washer, electric massager, air negative ion generator, etc.
⑦ Audio-visual appliances: used in family entertainment, including TV sets (see TV receivers), radios, tape recorders, video recorders, cameras, stereos, etc.
⑧ Other electrical appliances: such as fireworks alarms and electric bells.
Some countries classify lighting appliances as a kind of household appliances, audio-visual appliances as entertainment appliances, including electric electronic toys; Some countries include household gas appliances (including fuel appliances) and solar appliances in household appliances. The United States adopts a mixed classification method to classify household appliances into large appliances, small appliances, air-conditioning appliances, household electronic consumer appliances, office appliances, commercial and public facilities appliances, sales and coin-operated appliances.
The basic requirements of products mainly include safety, practicality, reliability, novelty and low energy consumption.
Safe household appliances are widely used, and users do not necessarily have electrical knowledge, so their safety performance is very important, and it is required that electrical appliances will not cause personal injury accidents when mechanical or electrical failures occur. Most countries have promulgated regulations and standards for the safety management of household appliances, and some countries have enforced them through laws. The International Electrotechnical Commission (IEC) has promulgated the safety rules for household appliances. China stipulates that the national standard of household appliances is equal to or equivalent to IEC safety rules.
Practicality is the basic feature of household appliances. The product should have basic functions, reasonable structure and convenient operation, and users can use it correctly without special skills.
Reliability is a comprehensive index reflecting the quality of household appliances. Mean time between failures is the main index of the reliability of household appliances. In the production process of products, strict total quality management is needed to ensure the consistency and stability of product quality.
Novel household appliances have the characteristics of beautifying the family, so they should be decorative. The shape and appearance of products should not only have distinct times, but also reflect the scientific and technological level and people's aesthetic taste in a certain period, and also reflect the scientific structure, the rationality of material selection and the advanced technology.
Less energy consumption, improving the efficiency index of household appliances and reducing energy consumption are the long-term efforts of major manufacturers of household appliances. The American Energy Policy and Energy Conservation Act (1975 12) stipulates the minimum energy efficiency standards of 14 kinds of high-energy household appliances. 1In June, 979, Japan promulgated the Law on Rational Use of Energy, which determined the criteria for judging the energy efficiency of refrigerators and air conditioners with high energy consumption, and stipulated that energy efficiency labels should be set on specific products to facilitate consumers' choice.
The popularity of household appliances reflects the cultural and economic level of a country. Generally speaking, countries with high gross national product, high per capita income and high per capita electricity consumption have high household appliance penetration rate (see table).
The development of a superpower mainly includes the following aspects.
Intelligentization is widely controlled by computer, which improves the intelligence of household appliances and displays more times. Household appliances equipped with speech synthesis and speech recognition systems will be able to realize real man-machine dialogue. Home robots have come out.
Automation Various automation products, such as automatic household washing machines for washing, bleaching and drying, and microwave ovens for automatic cooking, have come out one after another. The home automation control system, which combines household appliances with computers, can make future families work at home, go to school at home, shop at home and seek medical treatment at home. This high degree of automation of family life may fundamentally change the traditional way of life of human beings and become a new symbol of human civilization.
Plastics for household appliances have good electrical insulation and economy, and are suitable for mass production. Plasticization of household appliances will develop faster.
Remarkable progress has been made in the research on energy-saving technology of energy-saving and multi-functional household appliances. The refrigerator has been developing continuously in the aspects of high efficiency compressor, low thermal conductivity insulation layer, improved refrigerant and reasonable matching of refrigeration system, and the power consumption has been greatly reduced. Absorption refrigerators that use a variety of energy sources also have new developments, and the output has increased rapidly. The most promising way to save electricity is to apply microelectronics and solar energy to household appliances. If high-performance and large-capacity solar cells are successfully developed, solar household appliances will develop rapidly.