The electrostatic ball should be called Van de Graaff generator, also known as Van de Graaff gas pedal, is a device used to generate electrostatic high voltage. The Van de Graaff generator uses a conveyor belt to transfer the generated static charge to the surface of a hollow metal ball. Van de Graaff generators are very easy to obtain very high voltages, with modern Van de Graaff generators having potentials of up to 5 million volts.
We can stand on an insulated chair and press our hands against the starter's spherical metal cover. Since the human body can also conduct electricity, when the starter is activated, the charge is transferred to our bodies. And because the charges on the hair repel each other, the hair stands up.
Structure as shown in the figure, hollow metal ball A placed on an insulated cylinder C, cylinder B is driven by the motor up and down the movement of the ribbon (insulated conveyor belt), the metal needle tip E and tens of thousands of volts of DC power connected to the other end of the power supply to ground, due to the needle tip of the discharge, the electric charge will continue to be sent to the conveyor belt on the B. The electric charge will be sent to the conveyor belt on the B, and the electric charge will be sent to the other side of the needle tip. Another metal needle tip F is connected to the inner surface of the conductor ball A.
When the electrically charged conveyor belt rotates to the vicinity of the needle tip F, due to electrostatic induction and corona discharge, the charge on the conveyor belt is transferred to the needle tip F, which in turn moves to the outer surface of the conductor ball A, making the conductor ball A electrically charged. As the conveyor belt continues to run, the charge on ball A grows and the potential increases. A metal ball with a typical radius of 1 meter can produce a high voltage of about 1 megavolt (to ground).
To minimize atmospheric leakage, increase the voltage, and reduce the size, the entire device can be placed in a steel tank filled with nitrogen at 10 to 20 atmospheres.
The Van de Graaff generator, which produces a positive polarity, can be used as an accelerating power source for positive ions, and the one that produces a negative polarity can be used in a highly penetrating X-ray generator.
Expanded Information:
Vandergraf starters are used as positive ion accelerators. p>The electric charge on the spherical shroud of the Van de Graaff starter can generate more than 10 million volts. In nuclear physics experiments, such high voltages can be used to accelerate various charged particles such as protons and electrons. In addition, this generator can also be used to demonstrate many interesting electrostatic phenomena, such as making hair stand up, attracting styrofoam balls, generating electric sparks, and spinning windmills with electric wind.
There are many applications of static electricity in our daily lives, such as photocopiers, electrostatic precipitators, and electrostatic paint spraying. In addition, recognizing static electricity allows us to avoid the dangers it can bring, such as tying a grounded chain to the end of a vehicle carrying flammable materials to transfer the electrical charge to the ground to avoid electrical sparks that can cause a fire. By the same token, hospital operating rooms, where oxygen and flammable anesthetics are often used, usually have anti-static floors, and all machines need to be grounded to prevent sparks from causing explosions.
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