L3 power board circuit diagram

1. It is the tag number of a device. It should be an inctor. The inctance is L

2. If we decompose CRT displays with physical images, there will be countless models, and the circuit layout of each model is also different. But the circuit principle between them is similar. With this feature, we can take a comprehensive view. Remove the back cover of the monitor, and the big glass cone is the picture tube. There are two main types of picture tubes in the market. One is self converging kinescope. This kind of kinescope is the mainstream. It can be divided into thick tube and thin tube. The other type is Sony's single gun three beam color tube. Due to the complex circuit structure, high debugging accuracy is required, and few of them are used now. The bottom is the motherboard. Along the power line access to the motherboard is the power part. The display mostly uses the secondary switching power supply. This part usually has a large electrolytic capacitor, which is the power filter capacitor. The specifications are basically about 400uf400v. Next to the capacitor, there will be a radiator, which is the power regulator. Connected to the high pressure nozzle of the picture tube is the row output transformer, and the part it is installed is the row part. Next to it, there is a capacitor with high back voltage and small capacity, which is row reverse capacitance. This part is connected to the line deflection circuit of the deflection coil at the tail of the kinescope through the printed board. The place where the deflection coil is connected to the heat sink of the printed board is the field deflection circuit. The circuit board on the picture tube is the video amplifier circuit. The part close to the micro switch on the panel is the control circuit. That's the general structure.

3. 1. Connect circuit board function
2. Read the chip information of the important integrated chips on the circuit board, in order to understand the chip function and the function in the circuit
3. Divide the circuit into moles to ensure that every component on the circuit board is divided into a mole. For example, there may be power mole, main control mole, signal acquisition mole, display mole and so on in the circuit. And use a multimeter to measure the components in the circuit which are not easy to be divided into moles
4. According to the divided circuit moles, start to draw the circuit diagram of each mole
5. Make sure that no components are pulled down when drawing the circuit diagram. Check the circuit diagram after drawing to make sure it is correct
6. Analyze the circuit function to ensure the correctness of the circuit
if in the final analysis, it is found that a function is different from the typical circuit given in the chip data, it may be your drawing error, which needs to be checked

I hope I can help you!!!

4.

Step 1: set drawing properties

for the setting of sheet properties, you can execute the menu command design options, and the document Options dialog box will pop up, where you can select the sheet Options tab to set, as shown in the following figure. Make sure that the value of snapon in grids is set to 10, the value of visible is set to 10, the value of grid range is set to 8, the value of standard style is set to A4, and other settings are set by default, and then click OK to confirm

5. Here are the steps for me to draw the circuit diagram according to the circuit board:
1. First, take photos of the front and back sides of the circuit board with the camera (it's better to fix the camera so that the photos are the same size)
2. Open two photos with Photoshop and flip one of them horizontally, so that the positions of the two photos correspond
3. Overlay two images on different layers
4. Adjust the transparency of the image on the component surface to about 30% (subject to slightly seeing the component without affecting the printed circuit)
5. Merge layers and save them
in this way, you will have a circuit diagram that can clearly see the printed circuit and the components
follow this picture to create a component connection diagram
according to the component connection diagram, draw the approximate circuit diagram
organize the circuit diagram to make it standard
if the circuit is complex, sometimes it needs to be drawn many times
finally, compare the circuit diagram with the circuit board repeatedly, especially the key parts
the premise of doing this work is that you must have a fairly high foundation of electronic technology, otherwise you will not be able to understand if you draw a wrong picture
this work is very tedious and takes a long time. It is not good to do it without patience.

6.

How to look at the diagram:

1. Look at the main circuit

2. Looking at the control loop. The control loop should be from top to bottom and from left to right

3. Before reading the drawing, we must make clear the meaning of each electrical symbol

circuit diagram composition:

circuit diagram is mainly composed of four parts: component symbol, connection, node and annotation

The symbol of component represents the component in the actual circuit, and its shape is not necessarily similar to or even completely different from the actual component. But it generally shows the characteristics of the components, and the number of pins is consistent with the actual components

2. The connection line refers to the wire in the actual circuit. Although it is a wire in the schematic diagram, it is often not a wire in the commonly used printed circuit board, but a variety of shapes of copper foil blocks, just like many connections in the radio schematic diagram are not necessarily linear in the printed circuit board diagram, they can also be a certain shape of copper film

3. Node indicates the connection relationship between several component pins or wires. No matter how many pins and wires are connected with nodes, they are conctive

Note is very important in circuit diagram, and all words in circuit diagram can be classified as note. If you look at the above diagrams carefully, you will find that there are notes in every part of the circuit diagram, which are used to explain the model, name, etc. of the components

extended data:

composition structure

electrical system diagram mainly includes electrical schematic diagram, electrical layout diagram, electrical installation wiring diagram, etc., and drawing software includes electrical CAD, Protel99, cadence, etc

Therefore, the electrical schematic diagram is a kind of electrical system diagram. It is drawn according to the working principle of control line diagram, with simple structure and clear hierarchy. It is mainly used to study and analyze the working principle of the circuit

the electrical layout and installation drawing is mainly used to show the actual installation position of various electrical equipment on the mechanical equipment and in the electrical control cabinet. Provide necessary information for manufacturing, installation, maintenance and repair of mechanical and electrical control equipment

the electrical installation wiring diagram is for the wiring of devices, equipment or complete sets of devices, and provides detailed information of electrical connection between various installation wiring diagram items, including connection relationship, cable type and laying line

electrical schematic diagram label

common label: QS knife switch, Fu fuse, KM contactor, Ka intermediate relay, KT time relay, KS speed relay, FR thermal relay, Sb button, SQ travel switch

(1) list of electrical components: name, symbol, function, model, quantity, etc

(2) mark in small font beside the graphic symbols in the electrical schematic diagram

7. Buy a computer power supply, it should meet your needs!

8. Look at the circuit and see the changes

9.

Process of PCB generation:

1. First, design the schematic diagram according to the requirements of the project, that is, how to go the circuit, which electronic components are used, etc

2. Then use circuit diagram software, such as Protel or pads, to draw PCB board according to the schematic diagram. Drawing board is actually to arrange the package of these components and connect them to the line

The next step is to give the drawing to the PCB manufacturer. First, according to the size of the circuit board, cut a large board into small pieces that meet the requirements

4. Drilling, that is, some screw holes, some fixed installation holes, etc

After copper deposition, electroplating, film stripping, etching, green oil, screen printing characters, forming and testing, a PCB can be obtained

extended data:

PCB board classification -

1. Single panel: in the most basic PCB, the parts are concentrated on one side, and the wires are concentrated on the other side. Because wires only appear on one side, this kind of PCB is called single sided. Because there are many strict restrictions on the design circuit of a single panel (because there is only one side, the wiring can not cross, but must go around its own path), only the early circuits used this kind of board

Double sided board: this kind of circuit board has wiring on both sides, but to use the wires on both sides, there must be a proper circuit connection between the two sides. The bridge between these circuits is called via

the guide hole is a small hole filled with or coated with metal on the PCB, which can be connected with the wires on both sides. Because the area of the double-sided board is twice as large as that of the single panel, the double panel solves the difficulty of wiring interleaving in the single panel (it can be connected to the other side through the guide hole), and it is more suitable for more complex circuits than the single panel

Multilayer board: in order to increase the area of wiring, multilayer board uses more single or double-sided wiring board

a printed circuit board with one double-sided inner layer, two single-sided outer layer, or two double-sided inner layer and two single-sided outer layer is alternately connected by positioning system and insulating bonding material, and the conctive pattern is interconnected according to the design requirements, which is also called multi-layer printed circuit board

10. This board, 300 yuan will do. Pure design fee
34063 is very common and cheap in China
its circuit is also very simple. There are ready-made calculation formulas
anyone engaged in electronic development can do it

absolutely feasible. The current of the fan is generally 100-200ma. The current of USB is 500mA.

if you can't find someone to do it, you can call me.