Friends who often travel abroad know that they must bring a power converter to certain countries.
Due to the different power environments in different countries and regions, there are also differences in civil voltages, and the voltage application range of electrical appliances in different countries is also different. Let's first look at a group of civil electricity voltages in various countries: Voltage applicable countries 100V Japan, North Korea (only 2 countries) 110~130V United States, Canada, Panama, Cuba, Lebanon, Mexico and other countries and Taiwan, China, about 30 countries (regions) 220~230V United Kingdom, Germany, France, China, Singapore, Hong Kong (200V), Italy, Spain, Greece, Austria, the Netherlands, the Philippines, Thailand, Norway, Singapore, India, New Zealand, Australia... About 120 countries (regions) Of course, among countries that use 220~230V voltage, there are also cases where 110~130V voltage is used depending on regional needs, such as Sweden and Russia.
After listening to the introduction, my friend finally breathed a sigh of relief. It turns out that there are still many countries in the world that use 220V AC. Why doesn't my country use 110V AC like the United States? My friend's simple idea is: the lower the voltage, the safer it seems. This question is more complicated, and I will explain it slowly.
In 1879, Edison made a carbon filament incandescent lamp with relatively good effect. At that time, the incandescent lamp worked well under 110V DC voltage. Edison believed that this was a safe and economical voltage in power distribution. But later, another voltage level-220V was also recommended for use in the low-voltage field. After the two geniuses Edison and Tesla had a big argument over the issue of "strong DC or strong AC", the United States slowly began to generally adopt 110V AC.
Of course, in the development of the power system in the United States, many voltage types have actually appeared, but 110V and 220V are the main ones, and 110V gradually won in the development process.
With the advancement of electrical appliances and the development of transmission means today, there is actually no difference between 110V voltage and 220V voltage in use. So, why doesn't my country learn from the United States and adopt 110V AC voltage? Because, after the United States adopted 110V AC voltage, Europe believed that 110V voltage was too low, and the loss in transmission was too large (at that time, transformer and high-voltage transmission were not very common), and it was not powerful enough to drive some electrical appliances, so 220V was strongly promoted, and it was inherited by most countries later.
As we all know, the old China had low productivity and poor economy. It was of course very good to reduce losses and consumption of metals such as copper. 220V was easily accepted by power supply operators. In the 16th year of Guangxu in the Qing Dynasty (1890), Shanghai began to use incandescent lamps with a voltage of 100V. In the 27th year of Guangxu (1901), Shanghai International Settlement began to supply electricity day and night, and the voltage was changed to 200V. On September 12, 1930, the National Government announced China's first voltage and frequency standard in the form of a decree of the Construction Committee, stipulating that 220V and 50Hz were China's standard voltage and standard frequency. After the founding of New China, there were many things to be done, and it was of course very good to save a little. Therefore, the "rated voltage and frequency standards" and "power supply and use rules" formulated many times all use 220V as the standard. So, is 110V electricity safer than 220V electricity? In principle, the lower the voltage, the higher the safety. Someone has calculated that the time required for 110V to produce pathological physiological reactions or even fatal harm to the human body is indeed longer than 220V, with a difference of about 100 milliseconds... But in fact, both 110V and 220V are far beyond the range of safe voltage. In addition, when getting an electric shock, what really determines safety is the size of the current passing through, so whether there is danger depends more on the environment of the electric shock. Another question that a friend is very concerned about is:
Will some commonly used electrical appliances cause problems due to voltage differences when used abroad? If you bring ordinary electrical appliances of the same voltage system abroad, the voltage will generally not be a problem, because most electrical appliances have a 20% voltage fluctuation range, such as electric stoves, rice cookers, etc., because even in China, the voltage can sometimes reach up to 250V, so the 230V voltage just makes them heat faster, which is not a big problem. For those electrical appliances with strict voltage requirements and relatively expensive prices, even if they belong to the same voltage system, if the voltage is different, it is still recommended to use a travel transformer to avoid burning the electrical appliances or affecting the service life of the electrical appliances. If high-voltage electrical appliances are brought to low-voltage countries, such as 220V electrical appliances in China brought to the 110V environment in the United States, they generally cannot be used. Even if they can be used, they are often struggling or their functions are greatly reduced like an old cow pulling a cart. However, in the context of globalization, some smart international companies may have noticed the differences in voltages in various countries. Therefore, many electrical appliances designed have voltage adaptation, that is, they can be suitable for voltages of 110V-240V. Of course, if you often go abroad, travel agencies generally recommend that you bring your own travel conversion plugs and travel transformers when you go abroad.
