People in the power industry often say that they are engaged in "strong power." Correspondingly, those who engage in "weak power" generally claim to engage in IT, the Internet, telecommunications, etc. The name "weak power" was not good at all. The generalization is too general. However, “strong electricity” can claim to be self-declared, and it is clearer. Then why is electricity divided into “strong and weak”?

Some people think that strong and weak electricity is divided according to the voltage level. If the voltage is 220V or more and the power is less than 220V, then is the 110V power supply system considered as "strong" or "weak"? In fact, the fundamental difference between "weak power" and "power" is whether electricity is used as "energy" or used as "signal."

Before the 19th century, humans discovered electricity, such as frictional electrification, Leiden bottles, kite lightning, and voltaic batteries. However, because the electricity was too small to do anything, it did not have any major impact. The real impact of electricity began with the invention of telegraphy in the 1930s. It was discovered that in addition to doing some interesting experiments, electricity can also use the combination of “on and off” to transmit information. Morse uses a combination of long and short power. Time expresses the English alphabet, that is, the Morse code table, so electricity as a means of communication begins to enter people's lives. Until now, the technology of computer storage and computing - "1 and 0" is still represented by the level of potential.

The application of electricity as a signal is much earlier than the application of energy, and the first wire across the east and west coasts of the United States is the telegraph line instead of the power line. As early as before Westinghouse’s AC had occupied the global market, telegraphs and telephones had been used for many years. Even the Qing government used telegrams in the Westernization Movement of 1875.

The reason why telegraphy and telephony and other information and communications applications are far ahead of the application of electricity is that electricity as a signal does not require too much energy. It requires only high or low potentials or different frequencies to represent signals, and does not use work. The power application is different, electricity needs to drive the motor to do work, or flow through other electrical appliances to generate heat or light energy, which requires a lot of energy, only when the large machinery technology such as generators, motors and other mature, and can be long-distance high voltage transmission After the establishment of the power system, electricity can truly be used as an energy source for ordinary people. This is why the reforms in the telecommunications sector are far ahead of the reforms in the energy sector. In the final analysis, telecommunications are the transmission of signals, and electricity is the transmission of energy.

The transmission of signals is not limited by space and time. Broadcasting, satellite television, etc. have already achieved wireless transmission, and the optical cables connected to the Internet can realize the dissemination of large amounts of information at a very low input cost. The space for signal transmission is almost exclusive and competitive, and anyone can use it, which is why the information industry is a completely competitive industry. The transmission of energy must be limited by time and space. Only a limited amount of energy can be used or generated within a certain period of time, and only certain power can be transmitted in a certain space. Therefore, the energy transmission channel is exclusive, and railways, shipping, and power grids are all such that natural monopoly will occur.

Therefore, no matter how low the voltage level, as long as the energy is the transmission of energy is a strong electricity, no matter how high the voltage level, as long as the power of the transmission signal, it belongs to weak electricity. Here is also a suggestion for the selection of professional friends in colleges and universities. Motors, electromechanics, electric power, etc. No matter what professional name is called, as long as it is in the category of strong electricity, it is to deal with energy power, and we must look at the role of electricity in the eyes of energy. .

In order to transfer energy, "strong electricity" is generally very "strong." The AC has voltage levels of 10kV, 35kV, 110kV, 220kV, 500kV, and 1000kV, which is thousands of times higher than the 380V of residential electricity. The weak voltage general voltage level is not too high, the voltage is high, the dielectric strength of the material must be increased, need to fill more materials to insulate, the line can not rely on too close, otherwise the voltage breakdown, these are not conducive to the electronic Component integration. So one of the current developments of electronic components is to reduce the voltage, so that the integration of electronic components can be higher, the heat can be lower, of course, the voltage can not be too low, otherwise the high and low potentials representing 0 and 1 may not be able to distinguish between .