Miresaka momba ny olana sarotra amin’ny famatsian-jiro, 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: Fampisehoana herinaratra, làlan’ny fizotrany, fitakiana fiarovana, fiantraikan’ny EMC, sns.; Anisan’ny anton-javatra hodinihina, ny herinaratra no tena ifotony indrindra, fa ny EMC no tena sarotra takarina, ary ny tavoahangin’ireo tetikasa marobe dia mitoetra ao amin’ny EMC. Ity manaraka ity avy amin’ny torolàlana 22 hizarana ny birao PCB sy ny EMC.

1, boribory matotra mety ho PCB endrika tsy manam-paharoa famolavolana EMI

Azo eritreretina ny fiantraikan’ny fizaran-tany etsy ambony amin’ny EMC, eto ny sivana fampidirana; Lightning-proof pressure sensitivity; Fanoherana R102 hisorohana ny onjam-panafihana (miaraka amin’ny relay mba hampihenana ny fatiantoka); Key error mode X capacitance and Y capacitance with inductor filtering; Misy ny fisa misy ny tabilao fiarovana; Ny tsirairay amin’ireo fitaovana ireo dia manan-danja tokoa, ary ny fiasa sy ny asan’ny fitaovana tsirairay dia tokony hankasitrahana tsara. 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. Circuit sy EMC: (ny topology lehibe indrindra momba ny flyback, jereo ny ampahany lehibe amin’ny faritra misy ny rafitra 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. Fa ny onja elektrika miovaova dia miteraka sahan’andriamby miovaova, ary ny sahan’andriamby miovaova dia afaka mamokatra sahan’aratra (raha ny marina, io ilay fampitahana Maxwell malaza ary mampiasa fiteny tsotra aho), ary ny sehatry ny herinaratra miova dia afaka mamokatra andriamby ihany koa. saha. Ka alao antoka fa mandinika ireo toerana misy fanjakana na on / off ianao, izany no iray amin’ireo loharanon’ny EMC, ary ity dia iray amin’ireo loharanon’ny 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! Ny tadivavarana roa hafa dia tadivavarana mandray ary tadivavarana manitsy, takatrao mialoha, ary avy eo miresaka!

3. Fikambanana eo amin’ny famolavolana PCB sy ny 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. Ny ampahany amin’ny firafitra, ny famolavolana ny radiator dia tsy tsara dia hisy fiantraikany amin’ny fitsanganana ilay kinova miaro;

4. Raha ny faritra saro-pady dia manakaiky loatra ny loharano fanelingelenana, toy ny EMI circuit sy switch tube, tsy maintsy ihodivirana any amin’ny EMC mahantra izany, ary faritra mitoka-monina mazava no ilaina.

5. Fampidinana ny tadin’ny fitrohana RC.

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

Hiresaka momba an’io aho, ary hiresaka bebe kokoa momba izany, fa hanome anao fitarihana aho.

Here’s a quick example:

Araka ny aseho ao amin’ilay boaty misy teboka ao amin’ilay sary etsy ambony, dia nopetahana ny tariby X capacitor pin. Azonao atao ny mianatra ny fomba fanaovana ny tariby pin capacitor any ivelany (amin’ny alàlan’ny tariby mifehy ankehitriny). Amin’izany fomba izany, ny vokatry ny sivana amin’ny capacitor X dia mety hahatratra ny fanjakana tsara indrindra.

4. Fiomanana amin’ny famolavolana PCB: (raha vonona tanteraka ianao, ny drafitra dia mety mijanona tsikelikely hisorohana ny famolavolana endrika ary hanomboka indray)

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. Fisafidianana ny zotram-pifidianana: fisafidianana tontonana roa sosona, na tabilao misy sosona maro, arakaraka ny sary sy ny haben’ny birao, ny vidiny ary ny fanombanana hafa feno.

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. Ny halaviran’ny fuse pad dia mihoatra ny 3.0mm araka ny takian’ny fitsipiky ny fiarovana, ary ny takelaka tena izy dia 3.5mm (raha lazaina fotsiny, ny halaviran’ny creuse an’ny fuse dia 3.5mm aloha ary 3.0mm aorian’izay).

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. Ny lalàna mifehy ny fiarovana amin’ny dingana voalohany dia mitaky 6.4mm (elanelana elektrika), ary ny halaviran’ny pejin’ny pejy dia tokony ho 7.6mm. (Mariho fa mifandraika amin’ny volan’ny fidirana tena izy, mila manondro ny latabatra ho an’ny kajy manokana, ny angona natolotra ho an’ny fanovozan-kevitra ihany, arakaraka ny tena toe-javatra)

5. Cold ground and hot ground are clearly marked for the first stage; Marika L, N, INPUT AC INPUT marika, marika fampitandremana fuse sns.

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. Amin’ny fitsipiky ny fiarovana, takaro ny toetra mampiavaka ny toerana akaiky miaraka amin’ny takelaka PCB, toerana aiza no insulation fototra, toerana aiza no nohamafisin’ny insulation, tsy mitovy ny halaviran’ny insulation mahazatra. Ny tsara indrindra dia ny manamarina fenitra ary afaka manisa ny elanelan’ny herinaratra, ny halaviran’ny 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. Fifandraisana eo amin’ny capacitance Y sy ny fivoahan’ny rano ary ny fifandraisana ankehitriny.

Ary toy izany hatrany, hanazava amin’ny antsipiriany ny fomba handao ny elanelana, ny fomba hanaovana ny fepetra takian’ny fiarovana.

6, PCB famolavolana ny famatsiana herinaratra

1. Fandrefesana aloha ny haben’ny PCB sy ny isan’ny singa, mba hahatratrarana ny hakitroky tsara, na ny matevina, dia ho ratsy tarehy ny tsy fahampiana.

2. Modularize ny circuit, raiso ho ivony ny fitaovana fototra ary apetraho aloha ireo fitaovana ilaina.

3. Ny fitaovana dia mitsivalana na mitsivalana manohitra ny fametrahana toerana, ny iray tsara tarehy, ny iray mety plug-in miasa, toe-javatra manokana dia afaka mandinika mitongilana.

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

5. Ahenao araka izay azo atao ny faritra tadiavina mandritra ny fisehosehoana. Ireo tadivavarana efatra dia hazavaina amin’ny antsipiriany avy eo.

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

Ity manaraka ity no PCB virijiny voalohany notarihiko, taona maro lasa izay, sarotra be ny namita azy, mety misy olana kely eo afovoany, fa ny firafitra ankapobeny dia mendrika ny hianarana:

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. Ny terminal fampidirana sy famoahana dia raikitra ary tsy azo afindra. Ny tabilao dia mahitsizoro.

Eto dia ny layout dia hatrany ambany ka hatrany ambony, hatrany ankavia ka hatrany ankavanana, ary miankina amin’ny akorany ny fanaparitahana ny hafanana.

2.EMI circuit dia mbola mazava ny lalana mikoriana, izay tena zava-dehibe, raha tsy izany dia tsy tsara tarehy sy ratsy ho an’ny 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. Ny sosona ambony amin’ny herin’ny herinaratra mazàna dia miiba, ary ny sosona ambany kosa lasa tsara.

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. Fankasitrahana ireo ohatra 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! Behind will also be for this board to explain learning, we first enjoy.

8. Fahatakarana ny tadivavarana efatra an’ny famolavolana PCB: (ny fepetra takiana amin’ny fametrahana PCB dia ny faritra kely amin’ny tadivavarana efatra)

Ho fanampin’izany, ny fantsom-panafahana (ny fitrohana RCD, ny fitrohana RC ny fantsom-pifandraisana MOS ary ny fitrohana RC ny fantsom-panafody) dia tena zava-dehibe ihany koa, izay koa ny loop izay mamokatra taratra matetika. Raha manana fanontaniana momba ilay tarehimarika etsy ambony ianao, dia raisina an-tanan-droa. Tsy matahotra fanontaniana izahay.

9. PCB endrika hafanana (teboka mety hitsingevana) sy tariby mandeha amin’ny tany:

Zavatra mila saina:

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. Ny loop izay namboarin’ireo toerana mafana dia kely ary fohy ny tariby, ary ny matevina dia tsy matevina araka izay azo atao, fa raha mbola ampy kosa ny ankehitriny.

3. Ny tariby vita amin’ny tany dia tsy maintsy apetraka amin’ny teboka tokana. Ny tany lehibe sy ny tany famantarana dia misaraka, ny santionany dia mandeha misaraka.

4. Ny tany amin’ny radiator dia mila mifamatotra amin’ny tany lehibe.