Whether the cordless wristband is suitable for the electronics industry
The cordless wristband theory uses the principle of corona discharge to dissipate a part of the static electricity. The corona discharge is also called the tip discharge. After the body is charged, it usually needs a voltage of more than 1500V, and its tip part will discharge the air. Dissipates static electricity, but the static voltage required for dissipating static electricity in cordless wristbands is too high, and is not suitable for the electronics industry because there are many electronic components that can withstand high voltages above 1500V.
Corona discharge
Corona discharge
Partial self-sustained discharge of a gaseous medium in a non-uniform electric field. The most common form of gas discharge. In the vicinity of the tip electrode having a large radius of curvature, since the local electric field intensity exceeds the ionization field strength of the gas, the gas is ionized and excited, and corona discharge occurs. When corona occurs, light can be seen around the electrodes with a click. The corona discharge can be a relatively stable form of discharge or an early stage of development during a non-uniform electric field gap breakdown.
The formation mechanism of corona discharge is different due to the polarity of the tip electrode, which is mainly caused by the accumulation and distribution of space charge during corona discharge. Under the action of a direct current voltage, a negative corona or a positive corona agglomerates a space charge near the tip electrode. In a negative corona, when electrons cause impact ionization, electrons are driven away from the space of the tip electrode, and negative ions are formed, and positive ions are collected near the surface of the electrode. When the electric field continues to strengthen, positive ions are drawn into the electrode, and a pulse of corona current appears, and the negative ions diffuse into the interstitial space. Thereafter, the next ionization and charged particle motion process is repeated. This cycle so that many corona currents in the form of pulses appear. The phenomenon of corona current was discovered by G.W. Trichel in 1938 and is called the Tricher pulse. If the voltage continues to rise, the pulse frequency of the corona current increases, the amplitude increases, and the negative glow discharge is converted.
The voltage rises again, and a negative current discharge occurs, because its shape is also called a feather discharge or a brush discharge. When the negative current discharge continues to develop to the opposite electrode, it causes a spark discharge that causes the entire gap to break down. The positive corona also distributes positive ions near the tip electrode, but is constantly repulsed into the interstitial space, and electrons are attracted into the electrode, again forming a repetitive pulsed corona current. When the voltage continues to rise, a discharge discharge occurs and can cause a gap breakdown.
The power frequency AC corona has the same discharge process as the DC positive and negative corona in the positive and negative half cycles. The power frequency corona current is in phase with the voltage, reflecting the corona power loss. In engineering applications, the relationship between the applied voltage and the amount of corona charge is often used to indicate the corona characteristics, which is called the corrugation characteristic of corona. In fact, the surface condition of the wire, such as damage, raindrops, attachments, etc., makes corona discharge prone to occur.
Corona discharge has many effects in the field of engineering technology. Corona on the high-voltage and ultra-high-voltage transmission line wires in the power system can cause corona power loss, radio interference, television interference, and noise interference. When designing the circuit, you should choose a sufficient cross-sectional area of the wire, or use a split wire to reduce the electric field on the surface of the wire to avoid corona. For high voltage electrical equipment, corona discharges can gradually destroy the insulation properties of the equipment. The space charge of the corona discharge has the effect of increasing the gap breakdown strength under certain conditions. When lightning strikes or operating overvoltage occurs on the line, the overvoltage amplitude can be attenuated due to corona loss. Electrostatic dust removal, sewage treatment, air purification, etc. can be performed by corona discharge. The corona discharge of a pointed object such as a tree on the ground under the action of the earth electric field is an important part of participating in the electrical balance of the atmosphere. Corona discharge on the surface of the sea surface can promote the formation of organic matter in the ocean, and it may be one of the effective discharge forms of bio-prepared amino acids in the ancient atmosphere of the earth.
For different application purposes, corona discharge is an important technical issue.