Electrician basic knowledge _ maintenance electrician basic knowledge - solutions - Huaqiang electronic network
1) Resistivity - also known as resistivity or specific resistance. It is a physical quantity that measures the conductivity of a substance, expressed in the letter Ï, in ohms * mm square / meter. It is numerically equivalent to a wire having a length of 1 m and a cross-sectional area of ​​1 mm 2 made of that material. The resistance value at a temperature of 20 C, the higher the electrical resistivity, the lower the electrical conductivity. Then, the physical quantity of the resistivity of the substance changes with temperature, and its value is equal to the ratio of the increase of the resistivity to the original resistivity when the temperature rises by 1 C, usually expressed by the letter α, and the unit is 1/C.
2. The temperature coefficient of the resistance---- indicates the physical quantity of the resistivity of the substance that changes with temperature. The value is equal to the ratio of the increase of the resistivity to the original resistivity for every 1C increase in temperature, usually represented by the letter α. The unit is 1/C.
3, conductance ---- the ability of the object to conduct current is called conductance. In a DC circuit, the value of the conductance is the reciprocal of the resistance value, expressed in É¡, in ohms.
4, conductivity - also known as the conductance coefficient, is also a physical quantity to measure the conductivity of the substance. The magnitude is numerically the reciprocal of the resistivity, expressed in letters γ, in meters/ohms*mm square.
5. Electromotive force----The potential difference caused by the conversion of other forms of energy into electrical energy in the circuit is called electromotive force or short-term potential. Expressed by the letter E in volts.
6. Self-inductance----When the current in the closed loop changes, the magnetic flux passing through the loop itself is also changed by this current, so the electromotive force will also be induced in the loop. This phenomenon is called self-inductance. Phenomenon, this induced electromotive force is called self-induced electromotive force.
7. Mutual inductance----If two coils are close to each other, a part of the magnetic flux generated by the current in the first coil is looped with the second coil. When the current in the first coil changes, the magnetic flux with the second coil loop also changes, and an induced electromotive force is generated in the second coil. This phenomenon is called mutual inductance.
8
, inductance - the collective name of self-inductance and mutual inductance.
9, inductive resistance ---- AC current through the circuit with inductance, the inductance has the effect of blocking the AC current, this effect is called inductive reactance, expressed in Lx, Lx = 2Ï€fL.
10, capacitive resistance ---- AC current through the circuit with a capacitor, the capacitor has the effect of blocking the AC current, this effect is called capacitive reactance, expressed as Cx, Cx = 1 / 12Ï€fc.
11, pulsating current ---- the size of the current changes with time and direction, called the pulsating current.
12. Amplitude----The maximum value of alternating current in one cycle is called amplitude.
13. Average----The average value of the alternating current refers to the ratio of the total charge flowing through the circuit for a certain period of time to the period of time. The average of the sinusoidal quantities usually refers to the average value in the positive half cycle, which is related to the amplitude value: average value = 0.637 * amplitude value.
14. RMS----In two identical resistance devices, respectively, through direct current and alternating current, if the heat generated by them is equal at the same time, then the magnitude of this direct current is taken as the effective value of the alternating current. The effective value of the sinusoidal current is equal to 0.707 times its maximum value.
15, active power ---- also known as average power. The instantaneous power of the alternating current is not a constant value. The average value of the power in one cycle is called active power. It refers to the power consumed by the resistive part in the circuit, expressed in letter P, in watts.
16. Apparent power—In a circuit with resistance and reactance, the product of voltage and current is called apparent power and is expressed in letters Ps in watts.
17. Reactive power—In circuits with inductors and capacitors, these energy storage components store the energy of the power source into a magnetic field (or electric field) for half a cycle, during the other half of the cycle. The stored magnetic field (or electric field) energy is returned to the power source. They only exchange energy with the power supply and don't really consume energy. We call the amplitude value of the rate at which energy is exchanged with the power source called reactive power. It is represented by the letter Q, and the unit is èŠ.
18. Power factor ---- In the DC circuit, the voltage multiplying current is the active power. However, in an AC circuit, the voltage multiplying current is apparent power, and a part of the power (ie, active power) that can perform work is less than the apparent power. The ratio of active power to apparent power is called the power factor and is expressed in terms of COSφ.
19. Phase voltage ---- The voltage between the three-phase transmission line (hot line) and the neutral line is called the phase voltage.
20. Line voltage ---- The voltage between each line (hot line) of the three-phase transmission line is called the line voltage, and the line voltage is 1.73 times the phase voltage.
21. Phasor---In electro-technology, the vector used to represent the magnitude and phase of a sine is called a phasor, also called a vector.
22. Magnetic flux—The product of the magnetic induction intensity and the area perpendicular to the direction of the magnetic field is called the magnetic flux and is represented by the letter φ in Maxwell.
23. Magnetic flux density—The magnitude of the magnetic flux passing through a unit area is called the magnetic flux density. It is represented by the letter B. The magnetic flux density and the magnetic field induction intensity are numerically equal.
24. Magnetoresistance----similar to the meaning of resistance. Magnetoresistance is the obstructive effect of the magnetic circuit on the magnetic flux. It is represented by the symbol Rm and the unit is 1/hen.
25. Magnetic permeability—also known as magnetic permeability coefficient—is a coefficient that measures the magnetic permeability of a substance, expressed in the letter μ, in hen/meter.
26. Hysteresis----In the process of repeated magnetization of ferromagnet, its magnetic induction intensity always lags behind its magnetic field strength. This phenomenon is called hysteresis.
27. Hysteresis loop----In the magnetic field, the relationship between the magnetic induction intensity of the ferromagnet and the magnetic field strength can be expressed by a curve. When the magnetization magnetic field changes periodically, the relationship between the magnetic induction intensity and the magnetic field strength in the ferromagnetic body is A closed line, called a hysteresis loop, as shown in Figure 1.
28. Basic magnetization curve----The shape of the hysteresis loop of the ferromagnetic body is related to the maximum value of the magnetic induction intensity (or magnetic field strength). When the hysteresis loop is drawn, if the magnetic induction intensity (or magnetic field strength) is the largest When the values ​​take different values, a series of hysteresis loops are obtained, and the curve connecting the vertices of these loops is called the basic magnetization curve.
29. Hysteresis loss----The ferromagnet placed in the alternating magnetic field generates some power loss due to hysteresis, which causes the ferromagnet to heat up. This loss is called hysteresis loss.
30. Breakdown---The phenomenon that the insulating material is severely discharged or electrically conductive under the action of an electric field is called breakdown.
31. Dielectric constant---Also known as dielectric constant, dielectric constant or permittivity, which is a coefficient representing the characteristics of insulation capability, expressed by the letter ε, in units of law/meter.
32. Electromagnetic induction---When the magnetic flux of a conductor is changed, an electromotive force appears in the conductor. This phenomenon is called electromagnetic induction.
33, skin effect --- also known as the skin effect, when the high-frequency current through the conductor, the current will concentrate on the surface of the conductor, this phenomenon is called the skin effect.
1 When the circuit is marked by the color of the wire
1.1 Black: Internal wiring of devices and equipment.
1.2 Brown: The positive pole of the DC circuit.
1.3 red: three-phase circuit and phase C;
a collector of a semiconductor transistor;
A cathode of a semiconductor diode, a rectifier diode, or a thyristor.
1.4 yellow: phase A of the three-phase circuit;
The base of the semiconductor transistor;
The control pole of the thyristor and the triac.
1.5 Green: Phase B of a three-phase circuit.
1.6 blue: the negative pole of the DC circuit;
The emitter of a semiconductor transistor;
The anode of a semiconductor diode, rectifier diode or thyristor.
1.7 light blue: the neutral or neutral of a three-phase circuit;
The grounding neutral of the DC circuit.
1.8 white: the main electrode of the triac;
There is no specified semiconductor circuit.
1.9 Yellow and green two colors (each color width is about 15~100 mm alternately attached); safety ground wire.
1.10 Red, black parallel: AC circuit connected by double-core wire or double stranded wire.
2 When selecting the color of the wire according to the circuit
2.1 Phase A of the AC three-phase circuit: yellow;
Phase B: green;
Phase C: red;
Neutral or neutral, light blue;
Safety ground wire: yellow and green.
2.2 AC circuit connected by double-core wire or double stranded wire: red and black in parallel.
2.3 The positive pole of the DC circuit: brown;
Negative electrode: blue;
Grounding neutral: light blue.
2.4 The collector of the semiconductor transistor of the semiconductor circuit: red;
Base: yellow;
Emitter: blue.
Anode of semiconductor diode and rectifier diode: blue;
Cathode: red.
Anode of the thyristor tube: blue;
Control pole: yellow;
Cathode: red.
Control electrode of the two-way thyristor: yellow;
Main electrode: white.
2.5 The internal wiring of the entire device and equipment is generally recommended: black;
Semiconductor circuit: white;
When there is confusion: allow the selection of other colors outside the color (such as: orange, purple, gray, green blue, rose, etc.).
2.6 In the specific color standard, if there are two or more kinds of calibratable colors on one wire, depending on the specific condition of the circuit, the color is fixed according to a certain meaning that needs to be expressed in the circuit.
For busbars of certain products (such as marine electrical appliances), if there are international standards specified in the international market, and there are differences between the provisions of Articles 2.1 and 2.3, the color code specified in the international standard is also allowed to be color-coded.
ZGAR Foggy Box
ZGAR electronic cigarette uses high-tech R&D, food grade disposable pod device and high-quality raw material. All package designs are Original IP. Our designer team is from Hong Kong. We have very high requirements for product quality, flavors taste and packaging design. The E-liquid is imported, materials are food grade, and assembly plant is medical-grade dust-free workshops.
Our products include disposable e-cigarettes, rechargeable e-cigarettes, rechargreable disposable vape pen, and various of flavors of cigarette cartridges. From 600puffs to 5000puffs, ZGAR bar Disposable offer high-tech R&D, E-cigarette improves battery capacity, We offer various of flavors and support customization. And printing designs can be customized. We have our own professional team and competitive quotations for any OEM or ODM works.
We supply OEM rechargeable disposable vape pen,OEM disposable electronic cigarette,ODM disposable vape pen,ODM disposable electronic cigarette,OEM/ODM vape pen e-cigarette,OEM/ODM atomizer device.
Disposable E-cigarette, ODM disposable electronic cigarette, vape pen atomizer , Device E-cig, OEM disposable electronic cigarette,disposable vape,zgar foggy box
ZGAR INTERNATIONAL TRADING CO., LTD. , https://www.sze-cigarette.com