Isagoo ka hadlaya dhibaatada adag ee korontada lagu shido, 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: Waxqabadka korontada, waddada geedi socodka, shuruudaha badbaadada, saamaynta EMC, iwm. Waxyaabaha la tixgeliyo waxaa ka mid ah, korontada ayaa ah tan ugu aasaasiga ah, laakiin EMC ayaa ah tan ugu adag in la fahmo, dhabarjabinta mashaariic badanna waxay ku jirtaa EMC. Kuwa soo socda oo ka socda 22 tilmaamood si loo wadaago guddiga PCB iyo EMC.

1, wareegga qaangaarka wuxuu noqon karaa si raaxo leh PCB design EMI circuit

Saamaynta wareegga kore ku leedahay EMC waa la qiyaasi karaa, shaandheeyeyaasha gelinta ayaa halkan jooga; Lightning-proof pressure sensitivity; Resistance R102 si looga hortago kororka shoogga (oo leh gudbinta si loo yareeyo khasaaraha); Key error mode X capacitance and Y capacitance with inductor filtering; Waxaa jira fiyuusyo saamaynaya guddiga badbaadada; Mid kasta oo ka mid ah aaladahaani waa mid aad muhiim u ah, waana in si taxaddar leh loo qiimeeyaa shaqada iyo ficilka aalad kasta. 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. Wareegga iyo EMC: (topology -ga ugu caansan ee duulimaadka, fiiri qaybaha muhiimka ah ee wareegga ee ka kooban farsamada 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. Laakiin isbeddelka korantada ee hadda jira wuxuu soo saaraa goob magnetic ah oo is beddeleysa, iyo beddelidda birlabladu waxay soo saari kartaa goob koronto (dhab ahaantii, kani waa isla’eggii caanka ahaa ee Maxwell waxaanan isticmaalayaa luuqad cad), iyo beddelidda korantada ayaa sidoo kale soo saari karta magnetic garoonka. Markaa hubso inaad fiiro gaar ah u yeelato meelaha ay ka jiraan/ka maqan yihiin dawladaha, taasi waa mid ka mid ah ilaha EMC, tanina waa mid ka mid ah ilaha 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! Labada siddo ee kale waa siddooyin nuugid iyo siddooyin toosin, marka hore hore u sii fahan, ka dibna hadal!

3. Xiriirka ka dhexeeya naqshadeynta PCB iyo 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. Qaybta qaab -dhismeedka, soo -dhigidda naqshadeynta hiitarka ma fiicna waxay saamayn doontaa soo -dejinta nooca gaashaaman;

4. Haddii qaybta xasaasiga ahi ay aad ugu dhowdahay isha faragelinta, sida wareegga EMI iyo tuubada beddelka, waxay lama huraan u horseedi doontaa EMC oo liidata, waxaana loo baahan yahay meel go’doon ah oo cad.

5. Fiilooyinka wareegga nuugista RC.

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

Waxaan ka hadli doonaa arrintan, oo waxaan ka sii hadli doonaa wax badan, laakiin waxaan ku siin doonaa hoggaan.

Here’s a quick example:

Sida ka muuqata sanduuqa dhibicda ee shaxanka kore, fiilooyinka pin -ka X capacitor -ka ayaa la galiyay. Waxaad baran kartaa sida loo sameeyo fiilooyinka biraha capacitor -ka dibadda (iyadoo la isticmaalayo tuujinta fiilooyinka hadda jira). Sidan, saamaynta shaandhaynta ee X capacitor waxay gaari kartaa gobolka ugu fiican.

4. U diyaargarowga nashqadda PCB: (haddii aad si buuxda u diyaargarowday, naqshadu waxay noqon kartaa talaabo talaabo joogto ah si aad uga fogaato in naqshada rogmato oo aad dib u bilowdo)

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. Habka xulashada dariiqa: hal guddi oo ah xulashada guddi labalaab ah, ama looxyo badan, sida ku cad jaantuska iyo cabbirka guddiga, qiimaha iyo qiimayn kale oo dhammaystiran.

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. Fogaanta suufka fiyuuska gelinta ayaa ka weyn 3.0mm sida loogu baahan yahay xeerarka badbaadada, saxanka dhabta ahna waa 3.5mm (si fudud u hadalka, masaafada u dhexaysa fiyuusku waa 3.5mm ka hor iyo 3.0mm ka dib).

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. Xeerarka badbaadada ee marxaladda koowaad waxay u baahan yihiin 6.4mm (farqiga korontada), iyo masaafada u dhexaysa waa inay ahaataa 7.6mm. (Xusuusnow in tani ay la xiriirto danab -gelinta dhabta ah, waxay u baahan tahay inay tixraacdo miiska xisaabinta gaarka ah, xogta loo bixiyay tixraac kaliya, iyadoo ku xiran xaaladda dhabta ah)

5. Cold ground and hot ground are clearly marked for the first stage; Calaamadda L, N, calaamadda GELINTA AC, calaamadda digniinta fiyuuska iyo wixii la mid ah waa in si cad loo calaamadeeyaa;

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. Shuruucda badbaadada, fahan sifooyinka dahaarka ee meesha ugu dhow oo leh guddiga PCB, meesha ay tahay dahaarka aasaasiga ah, meesha lagu xoojiyay dahaarka, masaafada dahaarka caadiga ah ee kala duwan isku mid ma aha. Waxaa ugu wanaagsan in la hubiyo heerarka, lana xisaabin karo masaafada korontada, masaafada gurguurta.

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. Xidhiidhka ka dhexeeya Y capacitance iyo baxsiga hadda jira iyo kan hadda jira.

Iyo wixii la mid ah, waxay si faahfaahsan u sharxi doontaa sida looga tago masaafada, sida loo sameeyo shuruudaha badbaadada.

6, Naqshadeynta PCB ee qaabeynta korontada

1. Marka hore cabbir cabbirka PCB -ga iyo tirada qaybaha, si loo gaaro cufnaan wanaagsan, ama cufan, dhif iyo naadir ayaa noqon doonta mid fool xun.

2. Dib -u -habayn ku samee wareegga, u qaad aaladaha udub -dhexaadka u ah xarunta, oo marka hore dhig qalabka muhiimka ah.

3. Qalabku waa taagan yahay ama taagan yahay ka-hortagga meelaynta, mid waa mid qurux badan, kan kalena waa hawlgal fur-ku-habboon, duruufo gaar ah ayaa tixgelin kara janjeerin.

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

5. Yaree aagga loop intii suurtogal ah inta lagu jiro qaabaynta. Afarta loox ayaa si faahfaahsan loo sharxi doonaa goor dambe.

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

Kuwa soo socdaa waa PCB -ga bikradda ah ee ugu horreeyey ee aan sawiray, sannado badan ka hor, aad bay u adkayd in la dhammeeyo, waxaa laga yaabaa inay dhib yar dhexda ka jirto, laakiin qaab -dhismeedka guud ayaa mudan in la barto:

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. Terminallada gelinta iyo soo -saarka waa kuwo go’an oo aan la dhaqaajin karin. Guddigu waa leydi.

Halkan qaab -dhismeedku wuxuu ka socdaa xagga hoose ilaa sare, bidix ilaa midig, iyo kala -daadinta kuleylka waxay ku xiran tahay qolofka.

Wareegga 2.EMI wali waa jihada socodka oo cad, taas oo aad muhiim u ah, haddii kale uma qurux badna 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. Lakabka sare ee awoodda sare guud ahaan wuxuu noqdaa mid taban, lakabka hoose wuxuu noqdaa mid togan.

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. Qiimaynta tusaalooyinka 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! Gadaashu sidoo kale waxay u ahaan doontaa guddigan inuu sharaxo barashada, marka hore waan ku raaxaysanaa.

8. Fahamka afarta siddo ee naqshadeynta PCB: (shardiga aasaasiga ah ee qaabeynta PCB waa aagga yar ee afarta siddo)

Intaa waxaa sii dheer, loop nuugista (nuugista RCD, nuugista RC ee tuubada MOS iyo nuugista RC ee tuubada hagaajiyaha) ayaa sidoo kale aad muhiim u ah, taas oo sidoo kale ah loop -ka soo saara shucaaca soo noqnoqda. Haddii aad wax su’aalo ah ka qabtid shaxanka kore, waa lagu soo dhaweynayaa inaad kala hadasho. Kama cabsanno wax su’aalo ah.

9. Naqshadaynta PCB -ga meel kulul (dhibic sabayn karta) iyo silig dhulka ah:

Arimaha u baahan feejignaan

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. Loop -ka ay sameeyeen dhibco kulul wuu yar yahay xariguna wuu gaaban yahay, xariguna uma sii dhumuc weyn yahay intii suurtagal ah, laakiin inta uu hadda ku filan yahay.

3. Fiilada dhulka waa in lagu saleeyaa hal dhibic. Dhulka awoodda ugu weyn iyo dhulka signalada oo kala gooni ah, dhulka muunad qaadistu si gooni ah u tagaan.

4. Dhulka hiitarka wuxuu u baahan yahay in lagu xiro dhulka awoodda weyn.