Friday, December 28, 2018

Substrate for printed circuit boards

substrate for printed circuit boards
Printed circuit board (PCB) refers to the substrate carrying electronic components, and the substrate is the basic material of the circuit board. The manufacture of the printed circuit is completed on the substrate.
The base material mainly refers to the dielectric material, which is composed of resin reinforcements and fillers. The substrate is mainly based on the insulation part of the substrate as the classification standard of the common raw materials for electric boards glass fibreboard and various types of plastic boards. And the PCB system Manufacturers usually use
Make "adhesive tablets" for use.
Glass-assisted fiber national machine materials and mesh composition
The insulation of the
To ring the Arrow Street and the Steel Arrow
A metal box with a safety plate
Different thickness
Body of foil, in which
Divided into the following four categories.
Different solder, production
Properties of copper clad substrate
A plate scale made of copper foil
Steel substrates. Substrate plate
Phenolic paper based copper
The performance is also very different.
Copper base material
Same box substrate.
It's activated by insulation.
Cloth, coated with electrolytic copper case on its surface or on both sides. This paper or brocade fiber is dipped to match the tree tire, and the two sides are covered with unbroken glass
Aldehyde-resistant steel foil substrates as shown in figure 3.1
Made by hot pressing.
However, the high frequency and the mechanical strength are high, and the mechanical strength is low.
1.2 as shown, it is generally a discussion
Light yellow or black yellow price hard, widely used,
Easy water absorption and high temperature resistance
In general civil electronics such as radios
The performance is lower than that of surface insulation. Its price is easy
Epoxy phenolic glass silk foil substrate
It is not suitable for use in bad environment.
Made by hot pressing. Figure 3.1.3
Epoxy phenolic glass
It is made of alkali-free glass Cloth impregnated with aldehydes resin in electrolytic copper case,
The grease adhesive force is strong, the electrical insulation performance is good, not only the copper box substrate is turquoise green and has the transparent sense, because of the epoxy tree Can work at a frequency of up to 100 MHz,Chemical solvent, moisture resistant,Resistant to high temperature, suitable for use in harsh environments, this kind of board,commonly used in television, advanced instruments and so on, but its price is more expensive.
Epoxy glass cloth steel box substrate. It is made of epoxy resin of glass cloth spread with dicyandiamide curing agent and coated with electrolysis
Purple copper foil, made by hot pressing. The substrate has good transparency, good electrical and mechanical properties and high temperature and moisture resistance.
PTFE glass cloth copper foil substrate. It is impregnated with tetraneon dispersion emulsion by alkali-free glass cloth, coated with
The oxidized copper electrolytic box is made by hot pressing. It has excellent dielectric properties and chemical stability.
A new type of high temperature and high insulation material. The biggest feature is a wide range of adaptations, suitable for cutting-edge products and high frequency microwave
In the device.
When selecting the substrate of PCB, we should first consider that the substrate should have good electrical performance and sufficient mechanical strength.
                      From Allicdata

The choice of printed circuit board external connection

Selection of external connection Mode of printed Circuit Board

The printed circuit board must have the problem of external connection. The connection methods include wire welding, connector connection and so on.
Form.
1. Wire welding
Wire welding is a simple, inexpensive and reliable way to connect without any plug-in.
The external connection point of the wire welding PCB and the components outside the board can be made into other parts: the horn in the radio, the battery, the rotary group potentiometer switch in the electric production equipment, and so on, are all connected by wire welding. This method is characterized by low cost and high reliability, but it is not easy to maintain in the case of few external leads.
The following points need to be noted for wire welding.
The external points of the circuit version should be directed to the edge of the board. The ruler and spacing should be integrated to facilitate welding and maintenance, and the wires should be arranged neatly,  and sublines and boards should be arranged through wire clips or other fasteners.

2) in order to improve the mechanical strength of the wire connection and to prevent the wire from being pulled off the pad or printed line, it is best to drill a hole near the solder joint on the printed board to allow the wire to bypass the through hole from the welding surface of the circuit board, Then weld the pad hole from the element surface, Connector connection
Connectors are usually used in more complex instruments and equipment. The connection of insert part is that the external connection point on printed circuit board is connected by socket and off-board components. There are a wide variety of connectors, as follows.
Printed socket.  printed plugs are made at the edge of the printed circuit board and can be connected to the printed socket dedicated to the printed circuit board. This connection is convenient for maintenance and replacement and is suitable for mass production.

Other inserts. The external connectors of printed boards also include rectangular inserts, D-shaped inserts, circular inserts, and other types of connectorsWhen the printed circuit board external connection line is less often use the bar plug, such as the PC power line, sound card and CD ROM tone line, and so on.
If the printed circuit board has a large current signal external connection, you can use a rectangular connector. The plug is usually connected by flat cable. This kind of socket is too large to be straight
                       From Allicdata

Printed circuit board manufacturing process

Manufacturing process of printed circuit boards
 1. Manufacturing method of printed circuit boards
The manufacture of printed circuit board (PCB) is to transfer the printed circuit board diagram of printed circuit board to the laminated board of Shun Steel City. There are two methods of making it, that is, city formation method and addition method.
The subtraction method is also called the copper vending method, that is, the protective anticorrosive material
(1) is first applied to fill the steel foil with the substrate 1 to form the PCB pattern on the manufactured laminate and then to etch the unneeded part of the forest by chemical mechanical method. After the etching is over, the corrosion resistant layer is removed. The final step is a printed circuit made of copper foil.
The addition method, also called addition method, is the chemical deposition of copper on the insulating substrate without copper clad box. The anti-corrosion agent is used to transfer the reverse PCB plate diagram, and then the surface of the plate is cleaned and the metal layer is electroplated. At this time, the metal layer figure is the PCB board diagram. Then, the corrosion inhibitor can be removed.
At present, the commonly used method of making printed circuit board is subtraction method. According to the different methods of graphic transfer, the forming method is divided into screen leakage printing method, photographic sensitive offset printing method and graphic electroplating etching method and so on.

2. Manual fabrication of printed circuit boards
The main methods of handmade printed circuit board are tracing method, texturing etching method, copper foil pasting method and engraving method and so on. 1) tracing method
The most commonly used method for making printed circuit boards by hand is the tracing board.
1) shedding. According to the actual design size of copper clad laminate, cut the process of the baby pay attention to the board surface scratch, teach size, load shear whether there is a woolen problem. After hair and shear, use fine sand paper to form a special cleaning wave to remove the oil, rust and oxidation on the steel plate, and smooth the cards around the board to remove the hair and hair, then wash and dry with clear water to dry, wipe dry with F clean dishcloth
Extension map. Topograph is a reprinted circuit, that is, printed with paper on the coated steel sheet to print out the printed map that has been designed. In drawing, the printed wire is represented by a single line, and the suburban plate is represented by a small cluster point. It is particularly important to note that the double front plate is made with three positioning points, and this location point cannot be located in a straight line, without errors or omissions, and is then drilled in accordance with the drawing. After drawing, we should carefully check the plate of solder pad and wire. The hole must be drilled when drilling
Lead position using high speed precision table drill
Near the center and side of the plate.Too fast and too large to cause
When there is a gross margin around the clear hole
Description.
Do not stop the paper to clear,
In the absence of a system, it is not necessary to determine the shape of the traverse
Tracing is printing the heart.
When using the appropriate tone of the thin network
The silver sale of the reserved rice required for finishing shall be removed
Square corrosion layer. Tracing diagram
Vinegar, etc., can be used in colorless tracing
And please make all kinds of machine silver.
Additive 1 in liquid
Of materials such as shellac, alcohol, cortisone,
Line. Use hard guide when drawing embers
Measure methyl violet to facilitate
Wire dipped in lacquer
With soldering holes,
Observe the modification of Sichuan, trace the welding before drawing
Kefa's north view at this time, Kuo used the Tien kuenli power store
All sizes are checked as far as possible. And the paint for the traverse.
Dry graphic damage.
Have, do your best to use when you can use the workshop
I hot at both ends in case there will be no
Oil pen for existence

5) trimming.
Upon completion of tracing, inspection of pad and printing
That is, the drawing of the guidance line, whether there is a broken line or sand limit, if
Etch.
Timely repair and improvement, graphics in the
The burr or my remaining lacquer scraped off while repairing the broken thread.
Hot metal trioxide (or in proportion of 2:
When the tracing wave is fully F through,
Fully impregnate the board to a concentration of 28%-42%
Ten hydrogen peroxide at 2:1:2
In a container of hydrochloric acid + water) and stir gently back and forth
Liquid, etched to print graphics,
In the process of etching, for
At h
Speed up corrosion, brush the surface with a brush, or increase the etch
Concentration of liquid, not exceeding
Take out the board and stand side by side
The temperature of 50C is suitable for heating the liquid. All copper boxes to be installed on the plate are highly corroded
Rinse the 3min with etching water to remove the remaining corrosion solution.
Go to the paint film. After soaking in hot water, the paint film will fall off. The unremoved film can be scraped with a blade and then with a banana.
Removal of water by repeated wiping.
Repair board. Compare the etched circuit board with the schematic again, and trim the edge and welding of the printed wire with the etching knife.
The edge of the wire is neat, half smooth, and free of burrs. The pad is smooth and round and fine sandpaper is used to remove the burrs from the board. Wipe with rags.
Clean dirt, rinse with water and dry.
Apply flux. In order to facilitate welding and ensure the electrical properties of the circuit, it is necessary to apply flux and flux in the end.
It can protect the pad from oxidation and assist welding. The first thing to do is to use the rag cloth to clean the dirt.
After the completion of the cadaveric chart, when printing the drawing, the cutting tool silver f and the straight steel ruler are used to make the situation with the knife
Liu Tuo, with silver forceps F tear large do not need love copper. The micro grinding wheel can replace the knife directly on the steel foil.
Grinding out the desired graphics.

3. Manufacturing process of single-sided printed circuit board

Printing is the use of a laser printer with thickened paper to print the image of a designed printed circuit board to a hot transfer
Printed paper on a glossy surface (that is, a smooth surface). The function of transfer printing is to transfer the graphics on the heat transfer paper to the copper clad laminate. Transfer printing
The specific operation method is as follows: the printed heat transfer paper will flow on the copper clad laminate, the heat transfer machine will be pressed back and forth several times, so that
The melted toner is completely adsorbed on the copper clad laminate. After the copper clad laminate is cooled, the heat transfer paper can be removed.
One-sided board T art is simple, after making the board, there is no quality problem, but in case of million., before welding also Confucianism baby inspection t: print guide
Whether the wire and pad are clear and burr free, whether there is a bridge or break: whether the pad hole size is appropriate, whether there is a leak or not; or
Misalignment; the dimensions of the plate surface and the various processed parts on the board, especially the size of the plug part of the printed board, are accurate; whether the plate surface is accurate
Straight, no warp, etc.
4. Manufacturing process of double-sided printed circuit board
The difference between double-panel and single-sided board is that the electric circuit of double-sided printed circuit is realized by adding hole metallization I technique.
Connection. In addition, the production of photographic background and graphic electroplating etching is also a key step in the manufacture of double panels. Corresponding to different
Hole metallization process. The corresponding double panel manufacturing process there are also a variety of methods. At present, the commonly used method is to adopt
Graphic electroplating etching and SMOBC( Solder Mask Over Bare Cirouit, bare Copper coating Resistance Welding
Membrane method, here only the graphic electroplating method.
The graphic electroplating method with corrosion first and then electroplating has higher advantages. This method is especially suitable for line width and spacing.
In the manufacture of high density printed boards below 0.3mm, they are often used to produce both high precision and high density printed boards
Board. At present, most integrated circuit printed boards are produced by graphic electroplating.

1) pore metallization
On two or more layers of printed circuit boards-the connection of a sail wire is required to draw and interconnect the conductive figure of the inner layer
Signal metallization process. Hole Metallization is the key to PCB Manufacturing.Reliable method for making printed conductors for circuit boards.
Chemical deposition of copper on the surface of rear hole wall
And electroplating methods
Kong Jinhua's submission
Plating,
On the two floors, Jackie Chan
Book layer
Craft.
So that the golden hole machine sets up the required holes, however
Metallization of holes in actual production
Intersected between midcourse guidance lines
Going through.
Chemical deposition of copper electroplating copper thickening, etc. A
Pore metallization
The links are: drilling
Ask for Konneh's
Big oil one machine
Chemical cleaning liquid + shouting Wall speech
By the way, the electrical and mechanical properties are up to standard.

2) pasted photosensitive film
All metals are checked, linked with copper pin
After the hole is metallized, the bottom of the photograph should be taken)
Or light picture
Transfer of circuit graphics to overprint
On the copper sheet, in order to match the pattern rotation
In the process of moving, a layer of photosensitive adhesive clothing should be attached to the coated steel plate, that is, the road map should be kept silent.

3) production of photographic negatives
After the design of the printed circuit board is completed, the photographic negatives need to be drawn,
A negative film is usually used in the preparation of a plate, which is produced by a photographic plate making method CAD
A photographic film, which is the basis for the manufacture of printed graphics. Photographic negative
A sheet is an image that does not need to be preserved to cover with an image that is resistant to corrosion.
Light painting and printing method and other methods. Negative here
Copper foil protected by corrosion inhibitor is corroded, graphic electricity
After plating remove the corrosion inhibitor for etching, that is, the film face to see the negative image of the word.
The photographic plate making method is to take pictures of the black and white background drawing, and adjust the focal length of the camera before taking pictures.
In order to accurately achieve the design size of the printed board, the scale of the opposite proportion of the photographic base drawing for photographic negative is reduced in proportion, and the result is obtained.
To the mask used in production as specified in the design, the size of the panel shall be in accordance with the PCB. Photographic plate making
The process is basically consistent with general photography, including software tailoring. →Exposure. →→Development + fixing + washing thousands of dryness + repair board.
In order to prevent exposure of ultraviolet radiation through the film, resulting in incomplete development of the picture and text, the density of the film's transmittance is less than that of the film.
0.05, the partial density of light is more than 3. Negative film requires large contrast, no sandholes, no creases.
The method of CAD optical drawing is to use the CAD software first, and then use the PCB graphic data file to drive it.
Optical plotter,
The photographic background is drawn directly on the negative film by using light, and finally the exposure sensitive film is made by the operation of the light chamber.
Base film. The production of bottom film by CAD light drawing method has a fast speed.
, high precision and good quality
Drying, repairing boards. Etch plate anti-corrosion materials such as positive welding graphics, character marking graphics, etc., are printed through screen printing method.
Photochemistry usually begins with the first surface of the plate. Dip with a W layer of Guang Min resist and then expose the photographic negative on it. When exposed, the location of copper plate in M phase film should be accurate. Then through the development, retain the corrosion inhibitor formation of the circuit diagram, wash off the surface of the more than 1 anti-corrosion agent. Then the board was repaired to correct the adhesion, burr, and break of the pattern.
Line trachoma and other defects. The material used in repairing the plate must be corrosion-resistant.
At present, there are two kinds of photochemical methods: liquid photosensitive method and photosensitive 1 membrane method.
The liquid photosensitive method is to use the liquid photoresist to form the anti-electroplating agent. This method is suitable for the graphic transfer requirement of manufacturing high density printed circuit board. The process is as follows: pretreatment of substrate (acid treatment, brushing-+ coating drying). →Exposure development, dry etching (electroplating). →Remove the membrane.
The drying of photosensitive dry film is mainly composed of 1 film anticorrosive agent, polyester film and polyethylene film. (1) the anticorrosive agent of the film is an acid-resistant photopolymer, and the polyamide film is a substrate film with a thickness of about 30 μ m, which acts as an anticorrosion agent and a photographic film. Poly (ethylene-cautery) film is a protective layer which is covered by dry film etchant on polyester film. Its thickness is 30 ~ 40 μ m. The ten films can be divided into solvent type, whole water type, half water type and so on. The plate-making process of photosensitive dry film process includes: pretreatment (scrubbing and removing oxidizing film, oil stain, etc.)-blowing (drying-+ sticking film-+ orifice positioning-1). →Exposure-+ development. →Drying + repairing board + etching (electroplating). →Remove the membrane. The photosensitive adhesive 10 film process has the advantages of high production efficiency, simple process, high plate quality and so on.
At present, in the production of graphic electroplating, most of them adopt the photosensitive F film method and screen leakage printing method.
After the film, exposure, development, repair and other process PCB plate negative graphics have been transferred to the copper clad plate. Therefore, this "series" process is also called graphic transfer.
5) etching
Etching, also known as corrosion, is the process of using chemical or electrochemical methods to greatly remove copper foil that is not needed on a printed circuit board and to leave a simple printed circuit pattern. The commonly used etching solutions are three gasified iron, acidic or alkaline copper chloride, ammonium persulfate, complex acid, alkaline copper chloride and so on. Among them, the price of ferric chloride is low and the toxicity is low.The hot compressed air will melt the lead-tin alloy and blow the excess solder off the surface of the plate and inside the metallized hole. Finally, a bright, smooth and uniform solder coating is obtained. Hot air leveling process includes: flux-+ hot air leveling-+ cleaning, thousands of dryness, hot air leveling process in the solder temperature of 230 ~ 260C, time is 3 ~ 5s.
8) external surface treatment
The surface treatment of a printed circuit board includes coating a flux where the printed circuit board needs to be welded, printing a resistance layer on the place where the welding is not required, and printing a process such as graphics and characters where it needs to be marked. The flux is applied to improve the solderability of the board. The purpose of the flux is to improve the insulation of the board and to prevent circuit corrosion, especially on the high density lead-tin alloy board, which usually needs to be brushed in other parts other than the pad. To protect the board and improve the accuracy of welding. The flux is usually dark green or light green and can be divided into two types: heat curing and light curing.
                   From Allicdata

Printed circuit board features

3.1.2 characteristics of printed circuit boards
In electronic equipment, the main function of the printed circuit board: 1 provides the necessary mechanical support for the various components of the circuit. The circuit can work more stably and reliably. It realizes the wiring and electrical connection between various components and provides easily recognizable characters and graphics, which is easy to install, check and debug. In addition, the printed circuit board also has the following characteristics.
1) the PCB can ensure the consistency, reliability and stability of the manufactured products, which can greatly reduce the wiring errors and thus improve the assembly quality of the whole machine.
2) it is suitable for realizing automation in the whole machine assembly process, suitable for mass production, reducing the cost of the product and improving the efficiency of the whole machine assembly. It can not only realize the design standardization and machine unit, but also be convenient for maintenance.
The assembly and application of printed circuit boards do not require skilled workers and reduce the cost of training operators. (4) High density, small volume and light weight, which is helpful for the realization of lightweight and miniaturization of electronic equipment.
It also has the ability to continue to expand, to add printed components or directly encapsulate circuits into a fixed function
Component.
Its disadvantage is that the manufacturing process is more complicated and the single or small batch production is not economical.
                 From Allicdata

Soldering printed circuit board

Welding of printed circuit boards
Selection of electric soldering iron
When welding printed circuit board, the best choice of electric iron is 205W, the temperature is kept at 300C-350C, if the condition permits, you can choose the temperature-regulating type electric soldering iron. The shape of the iron head should be selected according to the size of the printed circuit board pad, generally using chisel or conical soldering iron head. Small tapered iron heads are often used for compact printed circuit boards with high density.
2. Heating methods
When the printed circuit board is heated, it is necessary to heat the copper box and the lead wire of the components on the printed circuit board at the same time by the soldering iron head. For large pads with a diameter greater than 5mm, the electric iron may be rotated from time to time, so as not to stay at a point for a long time and lead to a local Part overheating
3. Welding of polar components
When the capacitor is welded, it is welded in the order of the capacitive electrolytic capacitance of the expanded glass and the capacitor metal. Vertical welding diode also pay attention to the shortest lead of the diode coal connection time can not exceed 28. Triode is not resistant to high temperature, welding time can not be too long, S10s, welding is best to use silver f to use the Triode lead to help heat, prevent ironing pipe. High-power Triode welding-mounting of radiators or mats: insulation is smooth, and the common feet of the transistor must be used
The edge wire is connected to the board.
4. Welding of integrated circuits
In manual welding of integrated circuits, due to the small lead spacing of integrated circuits, it is necessary to select the appropriate soldering head and temperature, to prevent the connection of tin between leads, and to select internal thermal electric soldering iron less than 45W as a general rule. The daily ground wire should be in good contact. If the external heat type, it is best to use soldering iron off the residual heat welding, if necessary, also take human grounding measures.
It is best to weld the ground end and the power end of the integrated circuit first, and then to weld the human end. For integrated circuits that are particularly sensitive to temperature, cotton balls dipping with alcohol can be used to protect the roots of the components so that heat is as little as possible transmitted to the components. When welding the gate circuit, the input end should be handled correctly and should not be suspended. The time of each welding of the integrated circuit should be
Depending on the heat dissipation of the device.
When welding insulation book, double tree FET and CMOS integrated circuit, it is easy to induce electrostatic high voltage because of its high impedance and small capacitance between electrodes, which leads to device breakdown and damage. The lead wires of integrated circuits cannot withstand high temperature to prevent static electricity, also must be very careful when welding. It is best to use a stored electric iron for welding CMOS integrated circuits to prevent damage to the integrated circuits due to the weak leakage of the soldering iron.
There are two ways to assemble and weld integrated circuits: one is to weld the integrated circuit chip directly to the printed circuit board; the other is to use a special integrated chip socket / IC socket to weld the IC socket to the printed circuit board. Then the integrated circuit board is plugged into the human IC socket.
The IC shall be installed in accordance with the requirements of the corresponding position of the printed circuit board, and in accordance with the drawing requirements to further check the type of integrated circuit, pin position to meet the requirements, to ensure that the correct welding can be carried out.
7. welding of several vulnerable components
Easily damaged, these components are vulnerable elements in the welding process, such as heating or soldering iron containers, common vulnerable components such as cast plastic components, Reed components and so on.
In welding injection molding components, cast plastic components are widely used in manufacturing, the biggest characteristic of which is that they are not resistant to high temperature.
When welding cast plastic components and Reed components, attention should be paid to the preparation of surface cleaning and tin plating before welding. The prewelding process should not be repeated as successful as possible: the temperature of the soldering iron and iron should be appropriate. It is best to choose a sharper soldering head to prevent contact with adjacent solder joints during welding; the flux should be less used. Prevent the flux from dipping the electrical contact point of the human component, causing damage to the component; do not allow the electric iron to contact the component for a long time during welding, the heating time should be short, the welding time should be short, and the welding time should be short
Do not press the welded components.
8. Other
In addition, in PCB welding, if the wettability of solder needs to be enhanced, the method of surface cleaning and welding should be used, and it must be remembered that the friction pad or butt pad can not be used directly. For components with poor heat resistance, auxiliary T devices should be used to help dissipate heat to prevent damage to components.
If rosin is used as flux, it is necessary to clean up rosin after welding. The solder joints coated with inorganic flux must be scrubbed to avoid corrosion. After welding, use tweezers to gently pull each component pin to see if the welding is secure to prevent virtual welding. It should also be compared with the schematic diagram, carefully check whether there is leakage welding phenomenon.
                 From Allicdata

Thursday, December 27, 2018

How to choose an air switch

How to choose an air switch
The general principle of air switch selection:
The rated voltage of the air switch must be greater than or equal to the rated voltage of the line;
The rated current of the air switch and the rated current of the overcurrent release are greater than or equal to the line calculation load current.
Air switch selection is divided into two parts
Part of it is to learn how to look at the model specifications of the air switch, and the other part is to determine the air switch specifications that should be used in the home. The letter "D" in the air switch model indicates power and the letter "C" indicates illumination. At present, the family uses the air switch of the DZ series (small circuit breaker with leakage protection).
Air switch compared to traditional power switch
The air switch is a controller with a low-voltage distribution network and an electric drive system. The control and protection functions are more prominent during use. In the case of not fully contacting and breaking the circuit, the same paragraph or load for the electrical equipment To protection. In addition to this, it is also suitable to use the ground start motor. Air switch working principle: When the working current exceeds the rated current, short circuit, voltage loss, etc., the circuit is automatically cut off.
Determine the air switch model that suits your home needs
First check the size of the wire. If the wire allows a larger air switch, you can change the larger air switch, such as 1.5 square wire with C10 switch, 2.5 square wire with C16 or 20 switch, 4 square wire with C25 switch. , 6 square line with C32 switch, if the wire is too small, should be given a special line for high-power electrical appliances.
                      From Allicdata

How to repair the circuit board?

How to repair the circuit board?
Online measurement
Step 1: Power on the board. In this step, it should be noted that some boards are not single, they may need 5V, and they need positive and negative 12V, 24V, etc. Don't add the added power. It is. After the board is powered, touch the components on the board to see if there are any hot components. Check the 74 series chips. If the components are hot, the components may be damaged. After replacing the component, check if the board failure has been resolved.
Step 2: Measure the gate on the board with an oscilloscope and see if it is logical. If the output does not conform to the logic, it needs to be treated separately in two cases. One is that the output should be low level, the actual measurement is high level, and the chip can be directly judged to be damaged; the other is that the output should be high level. The actual measurement is low, and it is not possible to determine that the chip has been damaged. It is also necessary to disconnect the chip from the latter circuit, measure again, observe whether the logic is reasonable, and determine whether the chip is good or bad.
Step 3: Use an oscilloscope to measure the crystal in the digital circuit to see if it has an output. If there is no output, the chip connected to the crystal oscillator needs to be removed as much as possible before measurement. If there is no output, it is preliminarily determined that the crystal oscillator has been damaged; if there is output, it is necessary to replace the removed chips one by one, install a piece of the test piece, and find out the fault.
The fourth step: digital circuit with bus structure, generally includes three channels of digital, address and control bus. Use an oscilloscope to measure the three-way bus, compare the schematics, observe whether the signal is normal, and find out the problem.
                 From Allicdata

How to measure potentiometer

How to measure potentiometer
Method of measuring the potentiometer:
1, the detection of nominal resistance
When measuring, select the appropriate range of the multimeter resistance file, and connect the two test leads to the two fixed pin soldering pieces of the potentiometer. Firstly, measure whether the total resistance of the potentiometer is the same as the nominal resistance. If the measured resistance is infinite or larger than the nominal resistance, the potentiometer is open or damaged. Then connect the two hairs to either the center of the potentiometer and either of the two fixed ends. Slowly turn the potentiometer handle to rotate from one extreme position to the other. Normal potentiometer, multimeter indication The resistance value should be continuously changed from the nominal resistance (or 0Ω) to 0Ω (or nominal resistance). During the entire rotation process, the hands should change smoothly without any beating. If the needle has a beating phenomenon during the adjustment of the resistance value, it indicates that the potentiometer has a fault of poor contact. The detection method of the straight slide potentiometer is the same.
2. Detection with switch potentiometer
For the potentiometer with switch, in addition to the above method to detect the nominal resistance and contact of the potentiometer, it should also check whether the switch is normal. First rotate the potentiometer shaft handle to check if the switch is flexible. If there is a clear “click” sound when it is turned on or off. Use the multimeter R × 1 Ω file, the two test pens on the two external soldering pads of the potentiometer switch, rotate the potentiometer shaft handle, make the switch connected, the resistance value indicated on the multimeter should be changed from infinity (∞) to 0Ω. Turn the switch off again and the multimeter pointer should return to “∞” from 0Ω. During the measurement, the potentiometer switch should be turned on and off repeatedly to observe the reaction of the switch every time. If the resistance of the switch is not 0Ω at the "on" position and the resistance is not infinite at the "off" position, the switch of the potentiometer is damaged.
                From Allicdata

Friday, December 21, 2018

The wired mouse module has those electronic components

What are the components of the wired mouse module?
Electronic components include: resistors, capacitors, potentiometers, tubes, heat sinks, electromechanical components, connectors, semiconductor discrete devices, electro-acoustic devices, laser devices, electronic display devices, optoelectronic devices, sensors, power supplies, switches, micro-motors , electronic transformers, relays, printed circuit boards, integrated circuits, various types of circuits, piezoelectric, crystal, quartz, ceramic magnetic materials, substrate substrates for printed circuits, electronic functional materials, electronic adhesives, electronic products Chemical materials and parts, etc.
                            From Allicdata Electronic

How to measure the transformer is good or bad?

How to measure the transformer is good or bad?
Measurement methods:

1, power off measurement:

1 Transformer is composed of two sets of coils. Each set of coils is wound by a wire, so the resistance value can be judged as good or bad. The 220V input line is generally red line. The resistance value of this group of wires cannot be too small. When using the multimeter, the short circuit can not be short-circuited. If the short circuit is close to 0Ω, it will be broken. The red line generally has a resistance value of 30 Ω to 200 Ω. The larger the power, the smaller the resistance value and the smaller the power value.

2 If there is an open circuit, check the fuse. If the fuse is good, the internal line of the transformer input coil is broken. The output line is usually black line or other color, and the resistance is close to 0Ω. If the resistance is large or the circuit is broken, the line is broken.

2, power measurement:

Power on the multimeter AC AC test output line, if there is voltage output and stable is good, such as no voltage output or output voltage is not regulated is broken.

3, visual inspection:

Look at the appearance of the transformer, there is no trace of high temperature burnt, if there is a appearance of high temperature deformation is burned out.
                               From Allicdata Electronic

How to judge whether the capacitor is good or bad?

How to judge whether the capacitor is good or bad?
Before measuring the capacitance, be sure to discharge the capacitor, that is, after removing the capacitor, short-circuit both ends of the capacitor.
Look at the capacitance of the capacitor tag capacitor to select the appropriate gear. Let's take the 25 microfarad capacitor as an example.
Adjust the multimeter to the capacitor position. The adjusted position should be larger than the capacitance value on the capacitor label. We choose 200 microfarad.
Press the multimeter measurement button, which is usually labeled “Cx/Lx”, which is the measurement capacitor button. When pressed, the display will prompt.
Note that the test leads must be installed in both the COM and Cx jacks.
Finally, the two probes are used to contact the two ends of the capacitor. Generally, the measured value will be too large, but as long as the value is close to the label, the capacitor is normally available.
Be sure to discharge the capacitor before measuring, otherwise the multimeter may be burnt.
                            From Allicdata Electronic

How to identify and detect electronic components

How to identify and detect electronic components
First, the definition:
Electronic components are components of electronic components and small and small machines and instruments. They are often composed of several parts and can be used in similar products. They are often referred to as electrical, radio, instrumentation and other industrial parts, such as capacitors and transistors. The general term for sub-devices such as hairsprings and springs.
Second, identification:
Electronic components include: resistors, capacitors, potentiometers, tubes, heat sinks, electromechanical components, connectors, semiconductor discrete devices, electro-acoustic devices, laser devices, electronic display devices, optoelectronic devices, sensors, power supplies, switches, micro-motors , electronic transformers, relays, printed circuit boards, integrated circuits, various types of circuits, piezoelectric, crystal, quartz, ceramic magnetic materials, substrate substrates for printed circuits, electronic functional materials, electronic adhesives, electronic products Chemical materials and parts.
Third, testing:
Electronic components are fundamental elements in electronic circuits, usually in individual packages, and have two or more leads or metal contacts. The electronic components must be connected to each other to form an electronic circuit with a specific function, such as an amplifier, a radio receiver, an oscillator, etc. One of the common ways of connecting electronic components is soldering to a printed circuit board. Electronic components may be separate packages (resistors, capacitors, transistors, diodes, etc.) or groups of different complexity, such as integrated circuits (operating amplifiers, resistors, logic gates, etc.).
                          From Allicdata Electronic

Tuesday, December 18, 2018

GRM0225C1E4R2BA03L

GRM0225C1E4R2BA03L
ALLICDATA ELECTRONICS LIMITED 

Main product or service:
Various SMD.IC; Diode. Transistor. Three-terminal regulated field effect transistor. Darlington; SCR. Schottky; Electronic components; 1N4002 diode; Long-legged diode; High-power diode; Diode ES1D; Integrated IC; three-terminal voltage regulator FET; power amplifier tube; XL6013E1; boost LED driver; IC driver chip; integrated chip IC; trigger diode; low frequency amplifier; patch transistor; MB6S bridge stack;

Acting direct selling brand: AOS (American Bandai) Fairchild (FAIRCHILD) IR VISHAY (American Vishay) ON (Anson US) and other famous brands! Business scope: MOSFET (field effect transistor), TVS transient, Schottky, high frequency tube, three-terminal regulator, etc. Application products: power control, lithium battery protection, LED / LCD / display, notebook / tablet, GRM0225C1E4R2BA03L,model / electric toys, e-books, satellite navigation, etc.!

Specification
Description:CAP CER 4.2PF 25V C0G/NP0 01005
Detailed Description:4.2pF 25V Ceramic Capacitor C0G, NP0 01005 (0402 Metric) 0.016" L x 0.008" W (0.40mm x 0.20mm)
Categories:Capacitors
Ceramic Capacitors
Series:GRM
Packaging:Tape & Reel (TR)
Part Status:Active
Capacitance:4.2pF
Tolerance:±0.1pF
Voltage - Rated:25V
Temperature Coefficient:C0G, NP0
Operating Temperature:-55°C ~ 125°C
Features:-
Ratings:-
Applications:General Purpose
Mounting Type:Surface Mount, MLCC
Package / Case:01005 (0402 Metric)
Size / Dimension:0.016" L x 0.008" W (0.40mm x 0.20mm)
Height - Seated (Max):-
Thickness (Max):0.009" (0.22mm)
Lead Spacing:-
Lead Style:-
If you want to know more, please consult us.
Allicdata Electronics Limited.

GRM0225C1E4R1CA03L

GRM0225C1E4R1CA03L
ALLICDATA ELECTRONICS LIMITED 


The company provides different brands and models of similar products to meet the sophisticated and complex power requirements of modern advanced electronic products, reducing your cost while ensuring first-class quality and high performance, giving your products a great deal in the industry. Cost-effectiveness and competitive advantage. Business philosophy: The company has been a partner with famous electronic component manufacturers and agents in Singapore, Taiwan, Hong Kong and other countries for many years, and has the advantage of stable supply, reasonable price and prompt delivery! Through innovation and professionalism, we will continue to provide new products and services that exceed customer expectations and adhere to the best leaders in the industry! Dedicated to seek common development with you, please call to discuss!

We specialize in the operation of the highest quality SMD components: two, three transistors, capacitor tantalum capacitors, magnetic bead inductors, voltage regulators, the Department of Operations has a large number of stocks in the regular period. The brands with price advantage are: Murata, Philips, Kemei, AVX, Samsung, Toshiba, KEC, Panasonic, Changdian. , GRM0225C1E4R1CA03L,Roma, ON, TDK, Guoju.

Specification
Description:CAP CER 4.1PF 25V C0G/NP0 01005
Detailed Description:4.1pF 25V Ceramic Capacitor C0G, NP0 01005 (0402 Metric) 0.016" L x 0.008" W (0.40mm x 0.20mm)
Categories:Capacitors
Ceramic Capacitors
Series:GRM
Packaging:Tape & Reel (TR)
Part Status:Active
Capacitance:4.1pF
Tolerance:±0.25pF
Voltage - Rated:25V
Temperature Coefficient:C0G, NP0
Operating Temperature:-55°C ~ 125°C
Features:-
Ratings:-
Applications:General Purpose
Mounting Type:Surface Mount, MLCC
Package / Case:01005 (0402 Metric)
Size / Dimension:0.016" L x 0.008" W (0.40mm x 0.20mm)
Height - Seated (Max):-
Thickness (Max):0.009" (0.22mm)
Lead Spacing:-
Lead Style:-
If you want to know more, please consult us.
Allicdata Electronics Limited.

GRM0225C1E3R8CA03L

GRM0225C1E3R8CA03L
ALLICDATA ELECTRONICS LIMITED 


Our company adheres to the "integrity management, quality first" as the foundation of the industry! "Innovation, efficiency, professionalism, truth-seeking" is the foundation of entrepreneurship! Become a reliable bridge between customers and manufacturers. Years of market experience and brand direct sales provide high quality and assured service to electronics manufacturers.

Distribution of integrated IC ICs, diodes, transistors, capacitors and resistors sell well in the consumer market, enjoying a higher status among consumers. Focus on one-stop electronic components supporting services preferred by world-class manufacturers. Acting distribution of world famous brand integrated circuit brands: ALTERA, XILINX, TI, while distributing ADI, AVAGO, ON, GRM0225C1E3R8CA03L,ST, NXP, MAXIM, INFINEON, FCS.

Specification
Description:CAP CER 3.8PF 25V C0G/NP0 01005
Detailed Description:3.8pF 25V Ceramic Capacitor C0G, NP0 01005 (0402 Metric) 0.016" L x 0.008" W (0.40mm x 0.20mm)
Categories:Capacitors
Ceramic Capacitors
Series:GRM
Packaging:Tape & Reel (TR)
Part Status:Active
Capacitance:3.8pF
Tolerance:±0.25pF
Voltage - Rated:25V
Temperature Coefficient:C0G, NP0
Operating Temperature:-55°C ~ 125°C
Features:-
Ratings:-
Applications:General Purpose
Mounting Type:Surface Mount, MLCC
Package / Case:01005 (0402 Metric)
Size / Dimension:0.016" L x 0.008" W (0.40mm x 0.20mm)
Height - Seated (Max):-
Thickness (Max):0.009" (0.22mm)
Lead Spacing:-
Lead Style:-
If you want to know more, please consult us.
Allicdata Electronics Limited.

GRM0225C1E3R5BA03L

GRM0225C1E3R5BA03L
ALLICDATA ELECTRONICS LIMITED 


Our company is one of the professional companies that manage chip components in China. The company has always adhered to the spirit of honesty and quality as the purpose of enterprise development. As the leading distributor in the industry, the company always puts the customer's requirements first and makes everything perfect. From the customer's quotation processing, sample delivery certification, order confirmation to product delivery, all the company's well-trained employees will give you a pleasant surprise.

Main product or service:
Patch two triode; patch ceramic capacitor; chip tantalum capacitor; chip inductor magnetic beads; patch regulator tube;
Main industries: Zener diodes; GRM0225C1E3R5BA03L,other ceramic capacitors; other capacitors; Schottky diodes; other resistors; other triodes

Specification
Description:CAP CER 3.5PF 25V C0G/NP0 01005
Detailed Description:3.5pF 25V Ceramic Capacitor C0G, NP0 01005 (0402 Metric) 0.016" L x 0.008" W (0.40mm x 0.20mm)
Categories:Capacitors
Ceramic Capacitors
Series:GRM
Packaging:Tape & Reel (TR)
Part Status:Active
Capacitance:3.5pF
Tolerance:±0.1pF
Voltage - Rated:25V
Temperature Coefficient:C0G, NP0
Operating Temperature:-55°C ~ 125°C
Features:-
Ratings:-
Applications:General Purpose
Mounting Type:Surface Mount, MLCC
Package / Case:01005 (0402 Metric)
Size / Dimension:0.016" L x 0.008" W (0.40mm x 0.20mm)
Height - Seated (Max):-
Thickness (Max):0.009" (0.22mm)
Lead Spacing:-
Lead Style:-
If you want to know more, please consult us.
Allicdata Electronics Limited.

GRM0225C1E3R4BA03L

GRM0225C1E3R4BA03L
ALLICDATA ELECTRONICS LIMITED 


Our company is a business department that has been engaged in direct sales and operation for many years. And jointly produce a series of components with domestic and foreign manufacturers to establish a stable cooperative relationship. This business department relies on integrity! Excellent service! Gained the trust and dependence of the majority of customers. We specialize in the operation of the highest quality SMD components: two, three transistors, capacitor tantalum capacitors, magnetic bead inductors, voltage regulators, the Department of Operations has a large number of stocks in the regular period.

Camp products or services:
Electronic Components; Resistors; GRM0225C1E3R4BA03L,Capacitors; Diodes; Transistors; Tantalum Capacitors; Inductors; Magnetic Beads;
Main sectors: capacitors; transistors; resistors; inductor beads; diodes; integrated circuits (IC)

Specification
Description:CAP CER 3.4PF 25V C0G/NP0 01005
Detailed Description:3.4pF 25V Ceramic Capacitor C0G, NP0 01005 (0402 Metric) 0.016" L x 0.008" W (0.40mm x 0.20mm)
Categories:Capacitors
Ceramic Capacitors
Series:GRM
Packaging:Tape & Reel (TR)
Part Status:Active
Capacitance:3.4pF
Tolerance:±0.1pF
Voltage - Rated:25V
Temperature Coefficient:C0G, NP0
Operating Temperature:-55°C ~ 125°C
Features:-
Ratings:-
Applications:General Purpose
Mounting Type:Surface Mount, MLCC
Package / Case:01005 (0402 Metric)
Size / Dimension:0.016" L x 0.008" W (0.40mm x 0.20mm)
Height - Seated (Max):-
Thickness (Max):0.009" (0.22mm)
Lead Spacing:-
Lead Style:-
If you want to know more, please consult us.
Allicdata Electronics Limited.

Saturday, December 15, 2018

XA6SLX25-2CSG324Q

XA6SLX25-2CSG324Q
As a professional electronic components supplier, ALLICDATA ELECTRONICS] LIMITED is adhering to the "partnership" as the business concept, providing professional value-added services. ALLICDATA ELECTRONICS LIMITED continues to strengthen our core competitiveness and strive to enhance the professional knowledge and skills of our employees, so as to provide our customers with the best service to achieve the goal of quality optimization. Besides, we continuously provide product solutions for downstream manufacturers and upstream suppliers. In line with the "customer is god" principle, ALLICDATA ELECTRONICS LIMITED will create unlimited value for customers.

Main Business:
Our advantages products are: IC, semiconductor, memary, microprocessor, moudules, capacitors and other electronic components. The company has many years of business experience, first-class product technology, high quality, and high quality pre-sales and after-sales service. Our products sell well in China and far to Europe, America, Australia, Middle East and so on. Our company's quality commitment: with first-class products, first-class service and first-class reputation, we will build strong competitiveness for customers' product positioning, realize common concept, bring more demand resources for customers, and create more wealth for customers! We advocate: quality, reputation is our life; Pioneering and innovative is our source.

Product Features:
Description: IC FPGA 226 I/O 324CSGBGA
Manufacturer Standard Lead Time : 10 Weeks
Datasheets: XA Spartan-6 Overview
Design Resources: Development Tool Selector
PCN Design/Specification: Copper Wire Conversion 06/Jul/2015
PCN Assembly/Origin: Addition of Final Test Site 10/Feb/2014
Additional Warehouse Location: 17/Feb/2014
Categories: Integrated Circuits (ICs) Embedded - FPGAs (Field Programmable Gate Array)
Manufacturer: Xilinx Inc.
Series: Automotive, AEC-Q100, Spartan?-6 LX XA
Part Status: Active
Number of LABs/CLBs: 1879
Number of Logic Elements/Cells: 24051
Total RAM Bits: 958464
Number of I/O: 226
Voltage - Supply: 1.14 V ~ 1.26 V
Mounting Type: Surface Mount
Operating Temperature: -40°C ~ 125°C (TJ)
Package / Case: 324-LFBGA, CSPBGA
Supplier Device Package: 324-CSPBGA (15x15)
Base Part Number: XA6SLX25
Lead Free Status / RoHS Status: Lead free / RoHS Compliant
Moisture Sensitivity Level (MSL): 3 (168 Hours)

If you want to know more details, you can Google: ALLICDATA ELECTRONICS LIMITED.

Friday, December 14, 2018

Welding technology and soldering

Welding Technology and Tin Welding
Welding, also known as welding (welding), is the use of heating high temperature and high pressure way to join the enterprise or other thermal type materials manufacturing I art and technology.
Welding is usually divided into three categories, depending on the way in which the purpose of bonding is achieved,
1. Fusion welding
Fusion welding, also known as fusion welding, is one of the most common welding methods. In the process of welding, the workpieces that need to be welded are heated so that they melt locally. Because the welded workpiece is tightly attached, under the action of temperature field, gravity and so on, the molten liquid of the two workpieces will be mixed without external pressure. When the temperature is lowered, the melting part condenses and the two workpieces are firmly welded to complete the welding. If necessary, the weld can be added to the welding of the human melt filler assisted welding. The common arc welding, electroslag welding, gas welding, electron beam welding, laser welding and so on all belong to the fusion welding.
2. Brazing
Brazing refers to the use of filler metal with a lower melting point than that of the workpiece being welded (solder), which heats the workpiece and the powder to a higher melting point than the solder, and below the melting temperature of the workpiece being welded to moisten the workpiece by the capillary action of the liquid medium, The method of filling the joint yard and diffusing each other with the welded workpiece.
3. Contact welding
Genjit is a postal connection technology that can obtain reliable connections without the need for gauging materials and fluxes. Only at a temperature equal to or below the melting point of the welded workpiece, the welding method of infiltrating and joining the two workpieces by means of high pressure superposition, extrusion or vibration is used.
Needle welding is mainly used in the manufacture of electronic products. According to the melting point of solder is higher or lower than 450 degree, brazing can be divided into hard welding and soft welding. Tin welding is a kind of soft welding. It mainly refers to a method of welding with tin lead solder with low melting point.
Tin welding is one of the earliest and most widely used welding methods, which still occupies a large proportion at present. Compared with other welding methods, tin welding has the following characteristics.
1) the melting point of the solder is between 180 ~ 320C. Most metal materials can be welded by tin welding. During welding, the workpiece and welding section are heated at the same time, the solder melts and the welded workpiece does not melt.
The operation is convenient and the welding method is simple. Direct use of molten solder infiltration to achieve the solder joint, there are no precise requirements for heat and solder, the solder joint is easy to achieve.
The welding material is cheap, the welding tool is simple, and the welding cost is lower than other welding methods.
                            From Allicdata electronics

Solder joint quality requirements

1. Quality requirements for solder joints
After the circuit board is welded, we must carefully carry out visual testing. First of all, the components of one-press the positive, one by one view. The qualified solder joint not only has no virtual welding, but also the proper amount of solder, the size of the solder joint is uniform and symmetrical, the surface metal should be smooth, uniform, no porosity, no crack, no bump, no flux residue, Without drawing tip, crack and other defects of solder joints should show the profile of the lead.
1) the amount of solder on the solder joint should be appropriate
A good solder joint should be suitably soldered. Too little solder will not only affect the mechanical strength but also lead to the early failure of solder joint due to the gradual thickening of the oxide layer on the surface. Too much solder not only increases the cost, but also easily causes the short circuit of solder joint, and sometimes covers up the defects of welding.
When welding on printed circuit board, solder should be covered with pad, the shape should be centered by welding wire, the shape should be opened in skirt, the joint surface of solder should be half arched concave, the junction between solder and welding piece should be smooth, the contact angle should be as small as possible. If the solder joint is dissected with the component pin as the central axis, the section of the solder joint should be symmetrical "hyperbolic", and the smooth metal on the surface is a typical characteristic suitable for welding temperature. The qualified solder joints are approximately conical in shape, and the surface is concave in a slow slope, as shown in Fig. 2.5.7. The surface of virtual solder joint is often convex and can be identified.
The amount of solder is too little and unreliable, too much solder will weld the buried wire, but it is easy to lead to virtual welding. The virtual suburb will make the solder joint an unreliable connection state with contact resistance, which may lead to abnormal circuit operation or increased unstable noise. It is also easy to make the virtual welding parts fall off.
2) solder joint welding should ensure the quality of the solder joint will directly affect the conductivity.
To ensure a steady and reliable flow of current between welded parts, it is necessary to form an alloy layer on the surface of the solder and the broken part, rather than simply attaching the solder to the surface of the welding piece, or only a small portion of the alloy layer. However, no alloy layer was formed in the rest. This kind of solder with the surface of the solder does not form a alloy layer simple heap-attached or partially formed alloy layer tin welding is called virtual welding.
It is difficult to detect virtual welding by measuring the meter, and the solder joints may pass through rated currents steadily and reliably in the short term, but over a long period of time. If the surface of the alloy is oxidized, the passing current will become smaller or intermittently pass through the current, or it may not pass the current and cause the broken circuit, which will lead to the quality problem of the product. Therefore, in order to ensure that electronic products can work stably and reliably for a long time, the first step is to put an end to the phenomenon of virtual welding and ensure that the solder joint is in good contact.
3) having certain mechanical strength
The function of solder joint is to connect two or more components. In order to make the broken part not fall off, not only the electrical contact performance of the solder joint is good, but also the mechanical strength must be certain.
The main components of solder used in tin welding are tin and lead, both of which have relatively low mechanical strength. In order to increase the strength of the solder joint, it is generally required that the area of the alloy layer on the surface of the terminal of the welded piece be large enough. It can even be welded after bending the lead pin of the welded components to ensure the mechanical connection strength. Solder should not be too little during welding, otherwise it will affect the strength of solder joint.
4) Solder joint surface should be smooth, clean and glossy
Good solder joint surface should be bright and uniform color, no crack, no pin hole, no slag. The metallic gloss on the surface of solder joint is not only the requirement of beautiful appearance, but also the sign of the suitable welding temperature and the formation of alloy layer.
The reason why the surface of solder joint is not smooth is that the welding temperature is too high, and the direction, speed and flux of the soldering head are also concerned. During welding, if too much flux is used or the flux is not sufficiently volatilized, this will result in
The color of solder joint is uneven or dull.
The existence of burrs on the solder joint surface will not only affect the beauty, but also bring harm to electronic products, especially in the

                             From Allicdata electronics



Various types of pliers introduction

Various pliers
1) Steel wire pliers
Wire pliers are mainly used to cut cables, strip insulation layer bending core, loosening and fastening nuts and so on. Figure 2.3.10 shows the shape and structure of the steel wire pliers, the wrong ends of the pliers are composed of pliers, teeth, cutters and guillotine, and the clamp handle of the pliers is protected by an insulating sleeve. The insulation sleeve of the clamp handle is marked with the voltage value of the steel wire pliers. If the working environment exceeds this voltage range, do not live operation, otherwise there will be a shock accident. When using wire pliers to trim live cables, check for breakage in the insulated handle in addition to the voltage value of the insulating handle, in order to prevent electrical shock.
2) oblique pliers
Slanting pliers are used to cut and weld the wires, and can also be used to strip the insulation of the wires with the spire pliers. The head position of the oblique pliers is oblique, which is convenient for the oblique pliers to be cut close to the wire or metal roots. Figure 2. 3. 11 shows the shape of the oblique pliers. The common beveling forceps are 4 inches, 1 inch, 2. 54 cm), 5 inches, 6 inches, 7 inches and 8 inches. In practice, do not use sloping pliers to cut live double strands of wire; otherwise, the equipment connected by the cable may be damaged by a short circuit.
3) Needle-nosed pliers
Compared with other pliers, its tongs have a small, pointed head that can be operated in a small space. The utility model is suitable for clamping small metal parts and bending device leads. Especially in the disassembly of the bottom plate, in the person's hand does not reach the part of the operation, you must use sharp pliers.
When using, be careful not to knock on objects with sharp nosed pliers
You have to use sharp pliers.
Tip pliers are commonly used in 4 ~ 5 inches. Note that they cannot be used to knock on objects or hold fruit nuts. Do not pinch or cut larger objects with sharp pliers to prevent damage to the jaws; remember not to point the pliers at yourself and use them to
In case of accidental injury.
4) flat nose pliers
Xiaoping mouth pliers straight flat can be used for clamping the components of the pipe sound foot or wire, because its forceps do not have lines, so it is suitable for wire straightening and shaping. But flat nose forceps have thinner jaws and are not suitable for clamping nuts or requiring
Parts with greater force.
5) stripping forceps
Stripping pliers are mainly used to strip the insulation layer of the wire, and the wires stripped out by the stripping pliers are neat and not easy to break. There are many kinds of wire stripping slots such as 0.5 ~ 4.5mm wire on the wire stripping forceps. The forceps of automatic stripping forceps are divided into left and right ends: the pincers at one end are smooth and are used for clamping
Wire; the other end of the pliers have 0. S5 ~ 3mm and other notch slots, used for cutting and spalling conductor insulation.
The wire stripping forceps in use only need to put the wire to be pricked into the appropriate slot, at the same time, the two pliers are closed and released, the insulating skin will be separated from the core wire at this time. It is important to note that the wire cannot be cut off when peeling. In addition, the groove of the shears should be rounded after closing.
6) wire press forceps
Wire pressing pliers are mainly used to process cables and connectors. Depending on the size of the joint, the diameter of the presser hole built into the clamp is different.
                      From  Allicdata electronics

Thursday, December 13, 2018

GRM1555C1E151JA01D

GRM1555C1E151JA01D
ALLICDATA ELECTRONICS LIMITED 


Our company relies on technology and market-oriented, and has accumulated rich business experience. The company has stocks in stock for many years, and has established good cooperation with manufacturers and sales agencies in the US, Europe, Japan, Korea, Taiwan and China. relationship. The company is mainly based on the domestic market and its business is spread all over the world! Over the years, the company has earned a good reputation in the industry with its good credit, reliable quality, competitive price, fast logistics and flexible financial support.

Main product or service:
Schottky diode; switching diode; Zener diode; MOS field effect transistor; TVS/ESD electrostatic protection; amplifying diode; transient suppression; Zener diode; power IC; memory IC; potentiometer; connector; LED; Switching transistor;
Main industries: potentiometers; light-emitting diodes; Zener diodes; switching diodes; communication ICs; GRM1555C1E151JA01D,Schottky diodes

Specification
Description:CAP CER 150PF 25V C0G/NP0 0402
Detailed Description:150pF 25V Ceramic Capacitor C0G, NP0 0402 (1005 Metric) 0.039" L x 0.020" W (1.00mm x 0.50mm)
Categories:Capacitors
Ceramic Capacitors
Series:GRM
Packaging:Tape & Reel (TR)
Part Status:Active
Capacitance:150pF
Tolerance:±5%
Voltage - Rated:25V
Temperature Coefficient:C0G, NP0
Operating Temperature:-55°C ~ 125°C
Features:-
Ratings:-
Applications:General Purpose
Mounting Type:Surface Mount, MLCC
Package / Case:0402 (1005 Metric)
Size / Dimension:0.039" L x 0.020" W (1.00mm x 0.50mm)
Height - Seated (Max):-
Thickness (Max):0.022" (0.55mm)
Lead Spacing:-
Lead Style:-
If you want to know more, please consult us.
Allicdata Electronics Limited.

GRM1555C1E300JA01D

GRM1555C1E300JA01D
ALLICDATA ELECTRONICS LIMITED 


Our company is a supplier of electronic components. The company also acts as a multi-channel agent for “domestic and foreign brands”. Survive by quality, develop by quality. Our company has professional support staff, with the lowest cost and the best quality. Help you with one-stop components.

Main product or service:
IC; power IC; automotive IC; LED driver; communication IC; diode; switching diode; transistor; light-emitting diode; MOS field effect transistor; Schottky diode; rectifier diode; Zener diode; IGBT power module; ceramic capacitor; Capacitor; tantalum capacitor; resistor; GRM1555C1E300JA01D,inductor; potentiometer;


Specification
Description:CAP CER 30PF 25V C0G/NP0 0402
Detailed Description:30pF 25V Ceramic Capacitor C0G, NP0 0402 (1005 Metric) 0.039" L x 0.020" W (1.00mm x 0.50mm)
Categories:Capacitors
Ceramic Capacitors
Series:GRM
Packaging:Tape & Reel (TR)
Part Status:Active
Capacitance:30pF
Tolerance:±5%
Voltage - Rated:25V
Temperature Coefficient:C0G, NP0
Operating Temperature:-55°C ~ 125°C
Features:-
Ratings:-
Applications:General Purpose
Mounting Type:Surface Mount, MLCC
Package / Case:0402 (1005 Metric)
Size / Dimension:0.039" L x 0.020" W (1.00mm x 0.50mm)
Height - Seated (Max):-
Thickness (Max):0.022" (0.55mm)
Lead Spacing:-
Lead Style:-
If you want to know more, please consult us.
Allicdata Electronics Limited.

Tuesday, December 11, 2018

Understanding of variable frequency power supply: What kinds of load types does the variable frequency power supply have?

The variable frequency power supply can simulate the voltage standards of various countries in the world. The variable frequency power supply is suitable for resistive, capacitive, inductive and other non-linear loads. Different product loads and variable frequency power supply options are also different. The variable frequency power supply has several load types, and the different load types will be used differently. I don't know what the variable frequency power supply you know is. According to the frequency conversion power supply of Zhonggang Yangsheng, the inoculation load type is summarized for everyone:
1. Inductive load: start instantaneous current shock
2. Resistive load: The power factor is 1 or close to 1, and there is basically no inrush current.
3. Rectifying load: the peak coefficient of load current is relatively large
4. Mixed load: please select according to the proportion of different loads
The above is the type of load that the variable frequency power supply has. I don't know how much you know, I hope I can help you. Also pay attention when selecting the variable frequency power supply, do not choose the wrong, because if the choice is wrong, it is easy to have a certain impact in the process of use.
 From Allicdata electronics

When a triode is used as a switching circuit,

1. The base must be connected in series with a resistor to protect the base and protect the IO port of the CPU.
2. The base is based on a PNP or NPN tube plus a pull-up or pull-down resistor.
3. The collector resistance value is adjusted according to the actual situation of the drive current. The same base resistance can also be adjusted according to the actual situation.
The base and the emitter need a series resistor. The function of the resistor is to reliably turn off the transistor when the input is in a high-impedance state. The minimum value is that the transistor can be satisfied after the pre-driver saturates the transistor and the base-limit current resistor is divided. The critical saturation, the actual selection will be much higher than this minimum value, usually the smaller the external interference, the heavier the load, the higher the resistance value, usually 10K.
Prevent the triode from being affected by the noise signal and cause malfunction, so that the transistor is cut off more reliably! The base of the triode cannot be left floating. When the input signal is uncertain (such as when the input signal is high impedance), the pull-down resistor can be used to make Effective grounding.
In particular, when the GPIO is connected to the base, when the GPIO is just powered on and initialized, the GPIO is also in a power-on state. It is very unstable and is prone to noise and malfunction. Add this resistor. This effect can be eliminated (if a sharp pulse level occurs, this voltage is easily pulled low by the resistor due to the short time; if the high level is long, it cannot be pulled low, that is, at a normal high level. No effect)!
However, the resistance should not be too small, affecting the leakage current! (If it is too small, there will be a large current flowing from the resistor to the ground)
When the triode switch is activated, the ON and OFF times are as short as possible. In order to prevent the time lag caused by the residual charge in the transistor during OFF, an R is applied between B and E to discharge.

Definition of electronic components

Electronic components are the basis of electronic products. Understanding the types, structures, and performance of commonly used electronic components and correct selection are the basics of learning and mastering electronic technology. Commonly used electronic components are: resistors, capacitors, inductors, potentiometers, transformers, etc. In terms of installation methods, they can be divided into two types: traditional installation (also known as through-hole installation or DIP) and surface installation (also known as SMT). Or SMD). Transistors and diodes are called electronic devices.From Allicdata electronics
Classification of electronic components


1, according to resistance characteristics


Fixed resistors, adjustable resistors, special resistors (sensitive resistors).


Can not be adjusted, we call it a fixed resistance, and can be adjusted, we call it adjustable resistance, common, such as radio volume adjustment, mainly used for voltage distribution, we call it potentiometer.


2, according to the manufacturing materials


Carbon film resistors, metal film resistors, wirewound resistors, Czech resistors, thin film resistors, etc.


3, according to the installation method


Plug-in resistor, chip resistor.


4, by function


Load resistance, sampling resistor, shunt resistor, protection resistor, etc., the main parameters of the resistor:


a. Nominal resistance: The nominal value of the resistor on the resistor is called the nominal value. Unit: Ω, kΩ, MΩ. The nominal values ​​are marked according to the series of standards established by the state, and are not arbitrarily calibrated by the manufacturer. Not all resistance resistors are present.


b. Allowable error: The maximum allowable deviation range of the actual resistance of the resistor for the nominal value is called the allowable error. Error codes: F, G, J, K... (common error ranges are: 0.01%, 0.05%, 0.1%, 0.5%, 0.25%, 1%, 2%, 5%, etc.).


c. Rated power: refers to the allowable power consumption on the resistor under the specified ambient temperature, assuming that the ambient air does not circulate, in the long-term continuous operation without damage or substantially without changing the performance of the resistor. 16W, 1/8W, 1/4W, 1/2W, 1W, 2W, 5W, 10W...


A text to understand the role and diagram of electronic components


Common sense of electronic components


a. Correctly select the resistance and error of the resistor


b. Pay attention to the limit parameters of the resistor


c. The preferred general-purpose resistor


d. According to the characteristics of the circuit


e. Select the resistor according to the board size


Electronic components and diagrams


First, resistors and capacitors


(1) Resistor


We wire the battery, switch and bulb into the circuit of Figure 3-1. After the switch is closed, the current flows from the positive pole of the battery, and flows into the negative pole of the battery through the switch and the small bulb, and the small bulb emits light. Both the wire and the small bulb are electrically conductive and they are called conductors. In general, metals are conductors. When the current passes, the conductor has a certain hindrance to the current. This blocking effect is called resistance. The literal symbol for the resistor is R. The basic unit of resistance is ohms (symbol Ω), as well as larger units of kiloohms (KΩ), and megohms (MΩ). Their conversion relationship is:


1MΩ=10^3KΩ1KΩ=10^3Ω


A text to understand the role and diagram of electronic components


Figure 3-1 Lighting circuit


Commonly used resistors fall into two broad categories. A resistor with a fixed resistance is called a fixed resistor. Resistors with continuously variable resistance are called variable resistors (including emblem resistors and potentiometers). Their shapes and graphical symbols are shown in Table 3-1.


Resistors can also be classified into carbon film resistors, metal film resistors or wirewound resistors, etc. due to different materials.


What does the resistor do in the circuit?


Table 1 common resistors


A text to understand the role and diagram of electronic components


We replaced the switch in Figure 3-1 with a 470 ohm potentiometer (Figure 3-2(A)). Rotate the handle of the potentiometer, the brightness of the small bulb changes with the value of the resistance. The larger the resistance value, the darker the small bulb. This shows that the resistor can control the strength of the current in the circuit. We can refer to this circuit to make a small table lamp that can be dimmed.


A text to understand the role and diagram of electronic components


Figure 3-2 The role of resistors and capacitors in the circuit


There are two main parameters of the resistor:


  1. Nominal resistance and tolerance.


The value of the resistance marked on the resistor is called the nominal resistance. Such as 1.5K, 5.1Ω...... Its actual resistance allows a certain error, called tolerance, divided into I (±5%), II (±10%), and III (±20%). If the resistor is marked "3KΩI", it means that the resistance of this resistor is 3KΩ, and the error is 5%.


The nominal value and error of the resistor can also be represented by a color circle. Four colorful circular rings are printed on the resistor, three color rings next to the left end of the resistor indicate the resistance value, and the last color ring indicates the tolerance. The identification method is shown in Table 3-2.


The nominal value of the trimmer resistor and potentiometer is its maximum resistance. For example, a 100K potentiometer indicates that its resistance can vary continuously from zero to 100 kΩ.


  2. rated power.


Refers to the maximum power allowed while the resistor is operating normally. Above this value, the resistor will burn out due to the heat of distribution. In the electronic production involved in this chapter, if there is no special requirement, the resistors use 1/8w carbon film resistors.


(2) Capacitors


Two conductors that are insulated from each other and close to each other constitute a capacitor. The two conductors are called the two poles of the capacitor and are respectively led out by wires. The character symbol of the capacitor is C. Its size is measured in terms of capacitance. The basic unit of capacitance is Farah (indicated by F), and there are smaller unit microfarads (μF) and picofarads (PF). The conversion relationship of these three units is:


1F=106μF 1μF=106PF


Table two color circle representation

A text to understand the role and diagram of electronic components

A text to understand the role and diagram of electronic components


Capacitors can also be classified into fixed capacitors and variable capacitors depending on whether their capacitance can be changed. (including trimmer capacitors and variable capacitors) can also be divided into ceramic capacitors, electrolytic capacitors, air capacitors, etc., depending on the material being fabricated. The shape and shape of the capacitor are shown in Table 3-3.


A text to understand the role and diagram of electronic components


What is the role of the capacitor in the circuit?


We replace the switch in the circuit of Figure 3-1 with a capacitor (Figure 3-2(B)). When the circuit is turned on, we see that the small light bulb is no longer lit after it flashes. This is because the capacitor has a current in the circuit at the moment of charging. The charging process is quickly over, and after the capacitor is full of charge, the current disappears. The smaller the capacitor capacity, the shorter the time it takes to charge, and the DC current cannot pass through the capacitor. If the power is changed to AC power, the small bulb will continue to emit light. If the AC frequency can be changed, then at the same voltage, the high frequency AC lower frequency AC is easier to make the small bulb brighter through the same capacitor. These experiments can explain that the capacitor is in the circuit and can function as “DC-blocking, AC-passing” and “passing high-frequency, blocking low-frequency”.


There are also two main parameters of the capacitor:


  1. Nominal capacitance and tolerance. Nominal capacitance refers to the capacitance indicated on the capacitor. The allowable error is divided into three levels, which is the same as the representation of the resistor error. Trimmer capacitors and variable capacitors mark the minimum and maximum values ​​of their capacitance, such as 7/270P


  2. Withstand voltage. Refers to the highest voltage allowed on the capacitor when the capacitor is operating normally. Do not exceed, otherwise the capacitor will be damaged. In particular, it is necessary to point out that the two poles of the electrolytic capacitor have positive and negative points. They are polar capacitors. When used, they must be connected according to the circuit requirements. The two pins cannot be reversed.


Skill training, know resistors and capacitors


Purpose To recognize resistors and capacitors and learn to identify the resistance and error of the color ring resistor.


Equipment Resistors and capacitors of different sizes and types. 10 different color ring resistors.


Step


  1. Recognize resistors of different sizes and types, and read the nominal resistance and error of the resistors.


  2. Recognize capacitors of different sizes and types, and read the nominal capacitance and error of the capacitor.


3. Insert 10 color ring resistors on the cardboard and observe the color of the color ring (refer to Table 3-2), and write the nominal value and error of each resistor.


4. The students asked each other to check, 10 color ring resistors, how many of you identified correctly?


Second, transistors and integrated circuits


Transistors and integrated circuits are often used in electronic production. Transistors are divided into crystal diodes and transistor transistors, which are made of semiconductor materials, so they are also called semiconductor tubes.


(1) Crystal Diode


The text symbol of the crystal diode is VD, and its shape and graphic symbol are shown in Table 3-4.


Table 4 common diodes

A text to understand the role and diagram of electronic components


What is the role of a crystal diode in a circuit?


We connect the crystal diode to the switch position in the circuit of Figure 3-1 (Figure 3-3(A)). The light bulb illuminates, indicating that the diode is turned on and the resistance of the diode (called the forward resistance) is small. If the diode poles are reversed (as shown in Figure 3-3(B)), the small bulb will not light up. At this time, the resistance of the diode (called the reverse resistance) is large, and there is almost no current in the circuit. This phenomenon indicates that the diode has a unidirectional conductivity. Using this characteristic of the diode, diodes can be used for detection and rectification.


A text to understand the role and diagram of electronic components


Figure 3 Unidirectional conductivity of a crystal diode


There are two parameters for the crystal diode:


1. Maximum forward current: The maximum current allowed to pass when the diode is turned on.


2. Maximum reverse voltage: The highest voltage applied to the diode when the diode is turned off.


The above two parameters must not be exceeded in use, otherwise the diode will be damaged.


There are also special-purpose diodes, such as photodiodes, light-emitting diodes, etc., which are also commonly used in electronic production.


(two) crystal triode


The transistor is also made of a semiconductor material, and is classified into two types, PNP type and NPN type, due to different structures. The letter symbol of the triode is V. The shape and graphic symbols of commonly used triodes are shown in Table 3-5.


Table 3-5 Common Triode

A text to understand the role and diagram of electronic components

A text to understand the role and diagram of electronic components


The three poles of the transistor are called base (b), collector (c) and emitter (e). The arrow on the emitter indicates the direction of current flowing through the transistor. It can be seen that the current flow in the two types of triodes is reversed.


The transistor has amplifying and switching effects in the circuit. We use a transistor to amplify the weak signal current in the circuit or make an automatic switch to control the on and off of the appliance.


The working principle of the crystal triode is more complicated and will not be introduced here. The main parameters of the triode are the penetration current and the amplification factor. The smaller the penetration current Iceo, the better the stability of the triode. The magnification β is generally from tens to hundreds, and should be selected according to the needs of the circuit.


(3) Integrated circuits


In an integrated circuit, components such as diodes, transistors, and resistors and capacitors are fabricated on a small piece of semiconductor material according to the requirements of the circuit structure to form a complete circuit with certain functions, and then packaged. Its text symbol is IC, the shape and graphic symbols of common integrated circuits are shown in Table 3-6.


Table 3-6 Commonly used integrated circuits

A text to understand the role and diagram of electronic components


Integrated circuits were developed in the late 1960s with the development of electronic technology. Compared with circuits assembled using discrete components, the integrated circuit has many advantages such as fewer components, lighter weight, smaller size, better performance, and power saving. Therefore, the integration of electronic products has become an inevitable trend in the development of electronic technology.


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