Negative half-circumference flows from zero wire to fire wire, why is the fire wire always on with a stylus?
With a test pen to measure the firewire bright because the firewire voltage to ground for 220V, measurement, the firewire through the resistance within the pen through the human body to ground, at this time there will be a current flow, so it will be bright. And the zero line is zero volts to ground voltage, because the zero line itself is connected to the earth, and you are in the earth isotropic, so there is no potential difference, the formation of the current, so naturally not bright.
Why is the zero line zero, this is because it is grounded, the earth's potential is zero, so the natural zero line potential is zero. This is also the human body standing on the ground to grab the zero line will not be electrocuted.
Zero wire is the line from the neutral point of the transformer, it is the circuit after the fire wire to the electrical appliances, the zero line in the transformer mid-point of the lead will be grounded, so you can think of the zero line as a far away from the transformer is located in the ground, while the ground in the home is your home is located in the protective ground. Because the earth also has resistance, sometimes the zero wire in the home can be electrically charged, but the voltage is so small that it does not cause personal danger.
Positive half-week fire wire potential higher than the zero line, negative half-week fire wire potential lower than the zero line, water flows down, the current is the same, here to correct a misunderstanding, many people think that the current can only be the positive pole to the negative pole, in fact, the current also flows from the potential of the high positive pole to the potential of the low positive pole!
said here that the potential, mention this question may not understand, do not understand can also be understood as voltage, in fact, is not the same concept, the voltage is the potential difference, assuming that the potential is the height, the voltage is the difference in height, for example, there are two reservoirs in the mountains, a 100 meters (potential), a 150 meters (potential), then the difference in their heights (voltage) is 50 meters, if the two reservoirs are connected, the high water will flow to the lower one, if both are 150 meters (potential) it can't flow (voltage is zero) even if their heights (potentials) are high
If the above is understood, the potential of the zero wire is assumed to be the surface of the well, the height is fixed, the fire wire is a bucket filled with water, the height is variable, when the bucket is above the surface of the well, the water will flow to the surface of the well, and vice versa the water from the surface of the well flows to the bucket
Why is the stylus in the fire line bright in the zero line does not light, is the stylus tip need to be connected to the human body and then connected to the earth, and the zero line is also connected to the earth, they have the same high potential!
