The group of scientists squatted down and looked attentively at the paintings Liu Zheng drew on the ground.

Liu Zheng added: "If you want to understand the biggest difference between these two currents, you need to know a concept, voltage!"

"Voltage can be understood as the size of electricity!"

"In direct current, its voltage is constant and there is almost no change."

"As for alternating current, its voltage curves up and down like this."

"Electricity will be the focus of our development in the future, but you see that the voltage of DC is constant and almost does not change. We have not invented a DC generator now, but does such a constant voltage mean that it is always strong and will not tire?

"

Everyone thought for a while, and someone said: "If this size is constant, then we need to always ensure that it is strong, so as not to waste too many resources."

Liu Zheng snapped his fingers and said: "Yes, we know that energy is conserved. To maintain such a strong voltage, it does require more energy."

"And such a large voltage will also cause problems through the conductors we made."

"You can go and touch the copper wire harness coming out of our generator now. Is it hot or numb?"

Some people just don't believe in this evil, so they touch it, and the results are obvious.

Liu Zheng said everything. The small generator they built was very crude, with poor insulation and exposed copper wires, but this was not a problem.

The generators manufactured now only have moderately strong currents and will not cause harm to people.

Liu Zheng looked at the twitching scientist An Xie covering his hands, looking at him with admiration. Liu Zheng smiled and said, "Is it numb and a little hot?"

Everyone nodded.

Liu Zheng smiled and said: "This requires the introduction of two concepts, one is insulation and the other is resistance."

"Let's talk about insulation first. In the future, any wire harness or machine that is made to touch the current must have rubber on the outside to prevent the current from overflowing."

"You were numb just now because you were hit by an electric current."

"This is just a very low voltage, and the current generator has stopped. If the generator continues to output, you can imagine what kind of situation you will face."

"These currents will cause irreversible damage to your body. Please don't doubt what I say."

"If you have seen what happens to people who are struck by lightning, you should know that I am not alarmist!"

Everyone thought for a moment and shook their heads when they thought of the scene of being struck by lightning.

They don't want to experience that.

Liu Zheng added: "After talking about insulation, let's talk about resistance. The greater the voltage, the greater the current that these copper wires can pass, and they will become hotter and hotter."

"When the voltage reaches a certain level, these copper wires are likely to become hotter and hotter, and eventually..."

"Bang!" Liu Zheng pretended to light a fire: "It will burn."

"So DC is destined to be unsuitable for long-distance transmission. It is impossible for us to build so many power plants on Longyan that can be controlled within safe voltages."

"But alternating current can be transported over long distances, but the instantaneous current may also destroy electrical appliances, just like this telegraph machine we made, which suddenly burned down."

"It is also possible that the telegraph machine will not have stable voltage to operate."

"So we need to convert alternating current into a stable voltage, which requires a transformer."

"As for this tool that can change the voltage, you need to study it carefully. I don't have a good way to do this now."
Chapter completed!