Ngomong masalah angel pasokan listrik saklar, PCB cloth plate problems is not very difficult, but if want to cloth up a refined PCB must be one of the difficulties in switching power supply (PCB design is not good, may cause no matter how to debug parameter debugging cloth out of the situation, so not scaremongering) when reason was the PCB board consideration or a lot of, such as: Kinerja listrik, rute proses, syarat keamanan, pengaruh EMC, lsp; Antarane faktor sing bakal dipertimbangkan, listrik minangka sing paling dhasar, nanging EMC sing paling angel dingerteni, lan hambatan akeh proyek ing EMC. Ing ngisor iki saka 22 arah kanggo nuduhake papan PCB lan EMC.

1, sirkuit sing diwasa bisa dadi sirkuit desain EMB PCB sing santai

Pengaruh sirkuit ndhuwur ing EMC bisa dibayangake, filter input ana ing kene; Lightning-proof pressure sensitivity; Resistensi R102 kanggo nyegah arus kejut (kanthi relay kanggo nyuda kerugian); Key error mode X capacitance and Y capacitance with inductor filtering; Ana sekring sing nyebabake dewan safety; Saben piranti kasebut penting banget, lan fungsi lan tumindak saben piranti kudu dingerteni kanthi tliti. The EMC severity level should be considered when designing the circuit, such as the number of filters to be set, the number and location of the y-capacitor quantity. The choice of pressure-sensitive size and quantity is closely related to our requirements for EMC. Welcome to discuss the seemingly simple EMI circuit that actually contains profound truths for each component.

2. Sirkuit lan EMC: (topologi utama flyback sing paling umum, deleng bagean utama sirkuit sing ngemot mekanisme EMC)

The circled parts in the circuit in the figure above are very important for EMC (note that the green part is not), such as radiation. It is known that electromagnetic field radiation is spatial, but the basic principle is the change of magnetic flux, which involves the effective cross-sectional area of magnetic field, namely the corresponding loop in the circuit. The electric current can produce a magnetic field, which is stable and cannot be converted into an electric field. Nanging arus listrik sing ganti ngasilake medan magnet sing ganti, lan medan magnet sing ganti bisa ngasilake medan listrik (nyatane, iki persamaan Maxwell sing misuwur lan aku nggunakake basa biasa), lan medan listrik sing ganti uga bisa ngasilake magnet lapangan Dadi, priksa manawa sampeyan nggatekake papan sing ana ing / off negara, iku salah sawijining sumber EMC, lan iki minangka salah sawijining sumber EMC. For example, the dotted line loop in the circuit is the opening and closing loop of the switch tube. Not only the switching speed can be adjusted during the design of the circuit, but also the area of the wiring loop of the layout board has an important influence on EMC! Rong puteran liyane yaiku loop penyerapan lan puteran sing mbenerake, luwih dhisik ngerti sadurunge, banjur guneman!

3. Asosiasi desain PCB lan EMC

1.PCB loop has a very important influence on EMC, such as flyback main power loop. If it is too large, the radiation will be poor.

2. Filter wiring effect, filter is used to filter out interference, but if PCB wiring is not good, filter may lose the effect it should have.

3. Bagéan struktur, grounding desain radiator ora apik bakal mengaruhi grounding versi sing dilindhungi;

4. Yen bagean sensitif banget cedhak karo sumber gangguan, kayata sirkuit EMI lan tabung saklar, mesthine bakal nyebabake EMC sing ora apik, lan area isolasi sing jelas dibutuhake.

5. Kabel loop penyerapan RC.

6.Y capacitor grounding and wiring, and the position of Y capacitor is also critical!

Aku bakal ngomong babagan iki, lan bakal dakkandhakake luwih akeh, nanging aku bakal menehi pandhuan.

Here’s a quick example:

Kaya sing dituduhake ing kothak titik ing gambar ing ndhuwur, kabel pin kapasitor X wis diindentasi. Sampeyan bisa sinau cara nggawe kabel pin kapasitor eksternal (nggunakake kabel remet saiki). Kanthi cara iki, efek penyaringan kapasitor X bisa tekan negara paling apik.

4. Preparasi kanggo desain PCB: (yen sampeyan wis siyap, desain bisa terus-terusan langkah-langkah kanggo nyegah desain terbalik lan diwiwiti maneh)

There are roughly the following aspects, are their own design process to consider, all the content has nothing to do with other tutorials, are just their own experience summary.

1. Appearance structure size, including positioning hole, air channel flow direction, input and output socket, need to match with the customer system, also need to communicate with the customer assembly problems, height limit and so on.

2. Safety certification, products do what kind of certification, where do the basic insulation creepage distance to leave enough, where do strengthen the insulation to leave enough distance or slot.

3. Packaging design: there is no special period, such as preparation for customized packaging.

4. Pilihan rute proses: pilihan panel dobel panel siji, utawa papan multi-lapisan, miturut diagram skema lan ukuran papan, biaya lan evaluasi lengkap liyane.

5. Other special requirements of customers.

The structure and process will be relatively more flexible, safety regulations or relatively fixed part, what certification to do, what safety standards, of course, there are some safety regulations are common in many standards, but there are also some special products such as medical treatment will be more stringent.

For the new entry engineer friends are not dazzled;

Next list some general products general, the following is summarized for IEC60065 specific cloth requirements, for safety needs to keep in mind, encounter specific products will be targeted processing:

1. Jarak pad sekering input luwih gedhe tinimbang 3.0mm kaya sing dibutuhake dening peraturan keamanan, lan piring sejatine 3.5mm (cukup, jarak sekering sekring 3.5mm sadurunge lan 3.0mm sawise).

2. Before and after the rectifier bridge, the safety requirements are 2.0MM, and the plate layout is 2.5MM.

3. After rectification, safety regulations generally do not require, but the distance between high and low voltage is left according to the actual voltage, and 400V high voltage is left above 2.0mm.

4. Aturan keamanan kanggo tahap pisanan mbutuhake 6.4mm (celah listrik), lan jarak creepage kudu 7.6mm. (Elinga yen iki ana gandhengane karo voltase input sing nyata, kudu deleng tabel kanggo pitungan tartamtu, data sing diwenehake mung kanggo referensi, tundhuk karo kahanan nyata)

5. Cold ground and hot ground are clearly marked for the first stage; L, tandha N, tandha INPUT AC INPUT, tandha peringatan sekering lan sapanunggalane kudu ditandhani kanthi cetha;

It is reiterated that the actual safety distance is related to the actual input voltage and the working environment, so it is necessary to refer to the table for specific calculation. The data provided is for reference only and shall prevail in the actual situation.

5. Consider other factors for PCB design safety

1. Understand what certification their products do and what product categories they belong to. For example, medical treatment, communication, electricity, TV and so on are different, but there are also many similarities.

2. Ing peraturan keamanan, ngerti karakteristik jampel saka papan sing cedhak karo papan PCB, papan endi sing dadi insulasi dhasar, papan sing digawe kanggo jampel, jarak insulasi standar sing beda ora padha. Luwih becik mriksa standar, lan bisa ngetung jarak listrik, jarak creepage.

3. Focus on the safety devices of the product, such as the relationship between the magnetism of the transformer and the original side;

4. Radiator and surrounding distance problem, radiator insulation is not the same as the ground is not the same, the ground is cold, hot insulation is the same cloth.

5. Special attention should be paid to the distance of insurance, requiring the strictest place. The distance between front and rear of the fuse is consistent.

6. Hubungan antara kapasitansi Y lan arus bocor lan arus kontak.

Lan liya-liyane, bakal nerangake kanthi rinci babagan carane ninggalake jarak, cara nindakake syarat-syarat keamanan.

6, desain tata letak pasokan listrik PCB

1. Kaping pisanan ngukur ukuran PCB lan jumlah komponen, supaya entuk kapadhetan sing apik, utawa kandhel, jarang bakal elek.

2. Modulariake sirkuit, jupuk piranti inti dadi tengah, lan pasang piranti kunci dhisik.

3. Piranti anti-posisi vertikal utawa horisontal, siji apik, lan liyane gampang digunakake plug-in, kahanan khusus bisa dianggep miring.

4. Take cabling into consideration and arrange the layout in the most reasonable position for subsequent cabling.

5. Nyuda area loop sabisa nalika tata letak. Papat puteran kasebut bakal dijelasake kanthi rinci mengko.

Do the above points, of course, flexible use, more reasonable layout will be born soon.

Ing ngisor iki minangka PCB prawan pisanan sing dakgambar, pirang-pirang taun kepungkur, angel banget dirampungake, bisa uga ana masalah cilik ing tengah, nanging tata cara umum kudu dingerteni:

In this figure, the power density is still relatively high. The control part of LLC, the auxiliary source part and the BUCK circuit driver (high-power multi-channel output) part are on the small board, which is not taken out. Let’s take a look at the layout characteristics of the main power:

1. Terminal input lan output wis tetep lan ora bisa dipindhah. Papan kasebut persegi dowo.

Ing kene tata letak saka ngisor nganti ndhuwur, saka kiwa menyang tengen, lan disipasi panas gumantung karo cangkang.

2. Sirkuit EMI isih arah aliran sing jelas, sing penting banget, yen ora apik lan ora apik kanggo EMC.

3. The position of large capacitor should consider PFC loop and LLC main power loop as far as possible;

4. The current of the side side is relatively large. In order to run the current and dissipate the heat of the rectifier tube, this layout is adopted. Lapisan ndhuwur daya dhuwur umume dadi negatif, lan lapisan ngisor dadi positif.

Each board has its own characteristics, of course, also has its own difficulties, how to reasonably solve the key, we can understand the layout of reasonable selection of meaning?

7. Apresiasi conto PCB

I think it is a good place to do it. Of course, there will always be defects, which can also be pointed out. It is not easy for a single panel to be so compact, so you can use this board to learn and discuss! Ing mburi uga dewan iki nerangake babagan sinau, luwih dhisik kita seneng.

8. Pangerten patang puteran desain PCB: (syarat dhasar tata letak PCB yaiku area cilik saka papat puteran)

Kajaba iku, loop panyerepan (panyerepan RCD, penyerapan RC tabung MOS lan penyerapan RC tabung penyearah) uga penting banget, sing uga daur ulang sing ngasilake radiasi frekuensi tinggi. Yen sampeyan duwe pitakon babagan tokoh ing ndhuwur, sampeyan bisa ngrembug babagan kasebut. Kita ora wedi ana pitakon.

9. Titik panas desain PCB (titik potensial ngambang) lan kawat lemah:

Perkara sing butuh perhatian:

1. Pay special attention to hot spots (high-frequency switching points), which are high-frequency radiation points. Cable layout has a great impact on EMC.

2. Gelung sing digawe bintik-bintik panas iku cilik lan kabel-kabele cekak, lan kabel ora kenthel, nanging angger saiki cukup.

3. Kabel lemah kudu diiseni ing siji titik. Lemah listrik utama lan ground signal kapisah, lemah sampel dadi kapisah.

4. Lemah radiator kudu disambungake menyang lemah listrik utama.