1 Introduction to Protel Software With the rapid development of electronic information technology, the PCB (printed circuit board) of hand-designed electronic products can no longer meet the needs of the development of electronic technology. We must use the computer to complete the design of the PCB. It is not only fast, accurate, but also greatly reduces the labor intensity of engineers and technicians. There are many kinds of software involved, and Protel is one of the more classic ones. Protel is a circuit-aided design system from AlTIum. It is the first board-level design system that integrates all design tools, including schematic design, PCB design, circuit simulation, and PLD design. Its earliest version was the TANGO software package, which was later developed into Protel for DOS, Protel for Windows, Protel 98, Protel 99 SE, Protel DXP and Protel 2004. As the version continues to evolve, it is becoming more powerful. Compared to other versions, Protel 2004 adds many new features that make operation simpler and more automated, making it easy to perform complex board designs. 2 PCB design PCB is the abbreviation of English Printed Circuit Board, translated as printed circuit board, referred to as circuit board or PCB board. The printed circuit board is printed and fabricated into a conductive circuit and component package. Its main function is to realize the fixed installation of the electronic components and the electrical connection between the pins, thereby realizing various specific functions of the electrical device. Making the correct, reliable, and beautiful printed circuit board is the ultimate goal of circuit board design. The general process of PCB design includes: pre-production preparation, PCB component lead package, new PCB file, planning board, load component package and network, layout, routing, DRC design rule check, etc. 3 Ni-MH Battery Charger PCB Design The Ni-MH battery charger is an electronic product that is common in our lives. The basic steps for designing a printed circuit board (PCB) for this circuit with Protel 2004 are as follows. 3.1 Creating a project file To facilitate the management of each design file and the seamless connection and synchronization between them. In Protel 2004, using project files for management, you first need to create a project file, and then create or add each design file under the project file. 3.2 Create a schematic file and complete the schematic design of the battery charger circuit The schematic diagram of the Ni-MH battery charger circuit is shown in Figure 1. Figure 1 battery charger schematic 3.3 Create PCB files and plan There are two ways to create a PCB file in Protel 2004: create it with the File menu and create it with the wizard. Note that the PCB file created with the wizard is not in the project file. It must be placed in the project file after creation, otherwise it will be There is no way to proceed. According to the composition of the charger circuit, the shape of the board is first planned to be a rectangle, and the size of the board is determined to be 2400 mil & TImes; 1300 mil according to the number of components, and the single layer wiring is designed as a single panel. 3.4 Load component pin package and network and component layout All components in this circuit are in the form of a jack package. In addition to the battery pack's positive package, other components are packaged in the standard package of the Protel 2004 library. We need to set the package for the positive side of the battery pack according to the actual circuit. First, create your own component package library. The library is created as shown in BT1-BT4 in Figure 2, and then this package is set as the package of the battery pack. Figure 2 battery charger PCB diagram The component layout can be performed by first automatically arranging and then manually adjusting. Note that the transformer is not placed on this board. When layout, pay attention to the arrangement and distribution of components should be reasonable and uniform, and strive to be neat, beautiful, and meet the structural requirements of circuit structure. 3.5 Setting wiring rules and wiring The so-called "wiring" is to use the printed wires to complete the connection relationship of the components in the schematic. After completing the layout of any component board, the next step is to connect the components with wires to make them electrically, thus forming a complete circuit board. In Protel 2004, the wiring rules must be set first to meet the electrical requirements such as safety principles. According to the actual requirements of the charger circuit, the safety spacing is 10 mil, the top wiring, the common line width is 10 mil, the power line is 20 mil, and the ground line is 30 mil. The wiring is automatically routed, and the undesired place can be manually modified. Under the premise of meeting the electrical requirements such as safety principles, the wires should be streamlined, as short as possible, and bend as little as possible, so that the wires are simple and clear. In addition, the design of the wiring should consider whether the assembly is convenient or not. Finally, the board is required to be beautiful and economical. The good PCB board layout is beautiful and the work is fine. It looks like a piece of art. 3.6 DRC design rule checking and error elimination. After the circuit board design is completed, in order to ensure that the design work performed meets the requirements, the inspection work can be automatically performed by the computer, that is, the DRC design rule check. After the check is completed, the message dialog box will pop up, and according to this information prompt, the design will be modified until there are no errors. The PCB design work of the circuit is completed, and the designed charger PCB file is shown in Figure 2. Finally, you can print out the output drawings and reports, and carry out the corresponding follow-up work such as actual board making. 4 summary PCB design with Protel 2004 software is easy to operate and highly automated. The Ni-MH battery charger PCB design has the commonality of PCB design and also has certain characteristics. To design a perfect charger PCB, a lot of experience is required. With the development of electronic technology, electronic circuits are becoming more and more complex, requiring designers to continuously improve the design level and design more PCB boutiques.
Take a deep breath, close your eyes, the world has the freshest oxygen ... Yu Quan's "Deep Breath" is well known to us, but as the environmental problems become more and more serious, the haze sky also increases, PM2.5 PM10 and so on Vocabulary has also been mentioned more and more, and air purifiers have quickly become popular on the market with this "air quality" trend. Along with this, the air-clean brand has sprung up, and various technologies are dazzling. Which ones are indeed effective and which are just tasteless propaganda? How does the Air Purifier bother us to get rid of pollution? And look at the editors for you.
Analysis of air purifier
The critical value of PM2.5 content is 75 μg / m3
The pollutants in the air mainly include soot, total suspended particulates, inhalable particulates (PM2.5) and fine particulates (PM10). The smaller the diameter of the particulates, the deeper the part that can enter the respiratory tract. 10 micron diameter particles It is deposited in the upper respiratory tract, and particles below 2 microns can penetrate 100% into the bronchiole and alveoli.
1k-5k air purifier prices vary greatly
The air purifier products on the market not only have various functions, but also have prices ranging from thousand yuan to tens of thousands. The pricing of imported products is generally higher than that of domestic brands. Except for the core technology of many brands, the promotion of purification effects is similar, and consumers need to choose according to demand.
The air quality standard of 74 key cities is only 4.1%
According to the data of the press conference held by the State Council Information Office on June 4, according to the new "Ambient Air Quality Standards", the six pollutants SO2, NO2, PM10, PM2.5, CO and O3 were evaluated, 74 new standards In the first phase of monitoring and implementation, the proportion of cities that met the ambient air quality standards was only 4.1%, and the other 256 cities implemented the old air quality standards, and the proportion of cities that met the standards was 69.5%.
Air purifier sales increased by 90.5% compared with last year
According to a report recently released by the China Electronics and Information Industry Development Institute, due to the haze weather, air purifiers have become the most concerned home appliance products, with sales of nearly 2.4 million units nationwide last year, a year-on-year increase of 90.5%; retail The amount reached 5.6 billion yuan, a year-on-year increase of 105.9%.
HEPA filter needs to be replaced in March
The filter of the air purifier is the same as the filter of the water purifier, and it is not effective for a long time. After long-term use, the accumulation of dust on the surface of the filter will also cause the filter to gradually fail. Therefore, when the haze is more serious, the non-washable HEPA filter needs to be replaced every three months.
Merchants claim that the purification rate is more than 99% for the concept of stealing
99% or even 99.99% seems to have become a slogan for many air purifiers on the market. Many brands of products promote their high removal rate of PM2.5 and formaldehyde. In fact, this kind of publicity is more of a kind. The slogan of stealing the concept, the removal rate of 99% is the effect of the material itself on PM2.5 and formaldehyde, not the effect of actually running in space.
Air Purifier For Allergies,Dust Hepa Air Purifier,Portable Air Purifier,High Voltage Air Purifier Ningbo Zhe Kai Electric Appliance Co.,Ltd , https://www.cnairpurifiers.com
