Axaftina pirsgirêka dijwar a dabînkirina hêzê, 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: Performansa elektrîkê, riya pêvajoyê, pêdiviyên ewlehiyê, bandora EMC, hwd. Di nav faktorên ku divê bêne hesibandin de, elektrîkî ya herî bingehîn e, lê famkirina EMC ya herî dijwar e, û tengahiya gelek projeyan di EMC de ye. Ya jêrîn ji 22 rêgezan e ku hûn tabloya PCB û EMC parve bikin.

1, çerxa gihîştî dikare bi rengek sivik sêwirana EMI -ya sêwiranê be

Bandora çerxa jorîn a li ser EMC dikare were xeyal kirin, fîlterên têketinê li vir in; Lightning-proof pressure sensitivity; Berxwedana R102 ji bo pêşîlêgirtina şokê (bi relayê ku zirarê kêm bike); Key error mode X capacitance and Y capacitance with inductor filtering; Sîgorteyên ku bandorê li panelê ewlehiyê dikin hene; Her yek ji van amûran girîngiyek girîng e, û divê fonksiyon û çalakiya her cîhazê bi baldarî were nirxandin. 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 û EMC: (topolojiya sereke ya herî paşîn a naskirî, binihêrin ka kîjan perçeyên sereke yên gerdûnê mekanîzmaya EMC vedigire)

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. Lê guheztina elektrîkî guheztinek zeviyek magnetîkî ya guherbar çêdike, û guheztinek zeviyek magnetîkî dikare zeviyek elektrîkê çêbike (bi rastî, ev hevkêşeya navdar a Maxwell e û ez zimanek hêsan bikar tînim), û guherînek zeviyek elektrîkê jî dikare magnetîkî hilberîne erd. Ji ber vê yekê pê ewle bine ku hûn bala xwe didin cihên ku dewletên on/off lê hene, ew yek ji çavkaniyên EMC ye, û ev yek ji çavkaniyên EMC ye. 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! Du xelekên din pêlên vesazkirinê ne û xelekên rastkirinê ne, pêşî pêşî fam bikin, û dûvre bipeyivin!

3. Komeleya di navbera sêwirana PCB û EMC de

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. The structure part, the radiator design grounding is not good will affect the grounding of the shielded version;

4. Ger beşa hestiyar pir nêzîkê çavkaniya destwerdanê be, wek mînak çerxa EMI û boriya guheztinê, ew ê bêgûman bibe sedema EMC -ya belengaz, û qadek îzolasyonê ya zelal hewce ye.

5. Wiring of loop absorption RC.

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

I’m going to talk about this, and I’m going to talk about it more, but I’m going to give you a lead.

Here’s a quick example:

Wekî ku di quncika xalî de di jimara jorîn de tê xuyang kirin, têla têl a kondensatorê X ve hatî kişandin. Hûn dikarin fêr bibin ka meriv çawa kabloya kondensatorê wirînkirina derve dike (bi karanîna têlên tîrêjê yên heyî). Bi vî rengî, bandora parzûnê ya kondensator X dikare bigihîje rewşa çêtirîn.

4. Amadekariya ji bo sêwirana PCB: (heke hûn bi tevahî amade bin, sêwiran gav bi gav dikare domdar be da ku sêwiran ji serûbinbûnê û ji nû ve destpêkirinê dûr bikeve)

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. Hilbijartina rêça pêvajoyê: Hilbijartina panela dualî ya yek panelê, an tabloya pir-qat, li gorî nexşeya şematîkî û mezinahiya panelê, lêçûn û nirxandina berfireh a din.

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. Dûrahiya pêlika sîgorteya têketinê ji hêla rêzikên ewlehiyê ve ji 3.0mm mezintir e, û plakaya rastîn 3.5mm e (bi hêsanî diaxivim, dûrahiya çewlikê ya sîgorteyê 3.5mm pêş û 3.0mm piştî ye).

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. Qanûnên ewlehiyê yên ji bo qonaxa yekem 6.4mm (valahiya elektrîkê) hewce dike, û dûrahiya xêzikê divê 7.6mm be. (Têbigirin ku ev bi voltaja têketinê ya rastîn re têkildar e, pêdivî ye ku hûn ji bo hesabkirina taybetî serî li maseyê bidin, daneyên ku tenê ji bo referansê têne peyda kirin, li gorî rewşa rastîn)

5. Cold ground and hot ground are clearly marked for the first stage; Nîşana L, N, INPUT AC INPUT mark, nîşana hişyariya sîgorteyê û hwd divê bi zelalî bêne nîşan kirin;

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. Di rêzikên ewlehiyê de, taybetmendiyên vesazkirina cîhê nêzê bi tabloya PCB -yê fam bikin, kîjan cîh insulasyona bingehîn e, kîjan cîh insulasyona bihêzkirî ye, dûrbûna insulasyona standard a cihêreng ne yek e. Ew çêtirîn e ku meriv standardan kontrol bike, û dikare dûrahiya elektrîkê, dûrbûna xêzikê bihejmêre.

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. Têkiliya di navbera kapasîteya Y û leakage niha û pêwendiya heyî.

So hwd, ew ê bi hûrgulî rave bike ka meriv çawa dûrbûnê dihêle, meriv çawa hewcedariyên ewlehiyê dike.

6, sêwirana PCB -ê ya sêwirana dabînkirina hêzê

1. Pêşî mezinahiya PCB û jimara pêkhateyan bipîvin, ji bo ku bigihîjin dendikek baş, an dendikek, hindik dê xirab be.

2. Dorpêçê modul bikin, cîhazên bingehîn wekî navend bigirin, û cîhazên sereke pêşî lê bikin.

3. Amûr li dijî pozîsyonê vertical an horizontal e, yek xweş e, ya din operasyona pêvek a hêsan e, rewşên taybetî dikarin tiltê bihesibînin.

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

5. Di dema xêzkirinê de heya ku mimkun e qada loopê kêm bikin. Çar loop dê paşê bi hûrgulî bêne rave kirin.

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

Ya jêrîn yekem PCB -a bakî ye ku min kişand, gelek sal berê, qedandina wê pir dijwar bû, dibe ku di navîn de pirsgirêkek piçûk hebe, lê nexşeya gelemperî hêjayî fêrbûnê ye:

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. Termînalên têketin û derketinê sabit in û nayên guhastin. Lijneya çargoşe ye.

Li vir nexşe ji jêr ber bi jor, ji çep ber bi rast e, û belavbûna germê bi şêlê ve girêdayî ye.

2.Ekema EMI hîn jî rêça herikîna zelal e, ku pir girîng e, wekî din ew ji bo EMC ne xweş û xirab e.

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. Qata jorîn a hêza bilind bi gelemperî neyînî dibe, û ya jêrîn jî erênî diçe.

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. Pesindana nimûneyên 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. Understanding of the four loops of PCB design :(the basic requirement of PCB layout is the small area of the four loops)

Digel vê yekê, çembera vegirtinê (vegirtina RCD, vegirtina RC ya lûleya MOS û vegirtina RC ya boriya sererastker) jî pir girîng e, ku ew jî xelek e ku tîrêjê frekansa bilind çêdike. Heke di derheqê jimara jorîn de pirsên we hebin, hûn bi xêr hatin li ser wan nîqaş bikin. Em ji tu pirsan natirsin.

9. Sêwirana PCB -ya germ (xala potansiyela floating) û têla erdê:

Mijarên ku hewceyê balê ne:

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. Çerxa ku ji hêla deqên germ ve hatî çêkirin piçûktir e û têl kurt e, û têl bi qasî ku gengaz be ne qalind e, lê heya ku ya heyî bes e.

3. Pêdivî ye ku kabloya axê li yek xalî were ax kirin. Erda hêza sereke û axa îşaretê ji hev cihê dibin, axa mînakkirinê ji hev cihê diçin.

4. Erdê radyatorê pêdivî ye ku bi axa hêza sereke ve were girêdan.