Ag labhairt dó ar an bhfadhb deacair a bhaineann le soláthar cumhachta lasc, 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: Feidhmíocht leictreach, bealach próisis, riachtanais sábháilteachta, tionchar EMC, srl .; I measc na bhfachtóirí atá le breithniú, is é leictreach an ceann is bunúsaí, ach is é EMC an ceann is deacra a thuiscint, agus tá an tranglam i go leor tionscadal in EMC. Seo a leanas ó 22 treoir chun an bord PCB agus EMC a roinnt.

1, is féidir ciorcad aibí a bheith go taitneamhach ciorcad EMI dearadh PCB

Is féidir tionchar an chiorcaid thuas ar EMC a shamhlú, tá na scagairí ionchuir anseo; Lightning-proof pressure sensitivity; Friotaíocht R102 chun sruth turraing a chosc (le sealaíocht chun caillteanas a laghdú); Key error mode X capacitance and Y capacitance with inductor filtering; Tá fiúsanna ann a théann i bhfeidhm ar an mbord sábháilteachta; Tá gach ceann de na gairis seo ríthábhachtach, agus ba cheart feidhm agus gníomh gach feiste a thuiscint go cúramach. 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. Ciorcad agus EMC: (an phríomh-topology flyback is eolach, féach cé na codanna lárnacha den chiorcad ina bhfuil meicníocht 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. Ach táirgeann sruth leictreach atá ag athrú réimse maighnéadach atá ag athrú, agus is féidir le réimse maighnéadach atá ag athrú réimse leictreach a tháirgeadh (i ndáiríre, is é seo an chothromóid cáiliúil Maxwell agus tá gnáth-theanga á úsáid agam), agus is féidir le réimse leictreach atá ag athrú maighnéadach a tháirgeadh freisin. Gort. Mar sin déan cinnte go dtugann tú aird ar na háiteanna ina bhfuil stáit ar / as, sin ceann de fhoinsí an EMC, agus seo ceann de fhoinsí an 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! Is lúba ionsúcháin agus lúbanna ceartaithe iad an dá lúb eile, tuig ar dtús roimh ré iad, agus ansin labhair!

3. Comhlachas idir dearadh PCB agus 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. Beidh tionchar maith ag an gcuid struchtúir, nach bhfuil bunús dearadh an radaitheora ar bhunús an leagain sciath;

4. Má tá an chuid íogair ró-chóngarach don fhoinse cur isteach, amhail ciorcad IEA agus feadán lasc, is cinnte go mbeidh droch-EMC mar thoradh air, agus teastaíonn limistéar soiléir aonrúcháin.

5. Sreangú lúb ionsúcháin RC.

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

Táim chun labhairt faoi seo, agus beidh mé ag caint níos mó air, ach táim chun treoir a thabhairt duit.

Here’s a quick example:

Mar a thaispeántar sa bhosca breactha san fhigiúr thuas, tá sreangú bioráin an toilleora X curtha isteach. Is féidir leat foghlaim conas sreangú bioráin an toilleora a dhéanamh seachtrach (ag baint úsáide as an sreangú srutha brú). Ar an mbealach seo, is féidir le héifeacht scagtha toilleora X an stát is fearr a bhaint amach.

4. Ullmhúchán do dhearadh PCB: (má tá tú ullmhaithe go hiomlán, féadann an dearadh a bheith seasmhach céim ar chéim chun an dearadh a sheachaint agus tosú arís)

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. Roghnú bealaigh próisis: roghnú painéal dúbailte painéal aonair, nó bord ilchiseal, de réir na léaráide scéime agus méid an bhoird, costas agus meastóireacht chuimsitheach eile.

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. Tá fad an eochaircheap fiús ionchuir níos mó ná 3.0mm mar a éilíonn na rialacháin sábháilteachta, agus is é 3.5mm an pláta iarbhír (go simplí, is é 3.5mm an t-achar creepage den fiús roimh agus 3.0mm ina dhiaidh sin).

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. Éilíonn na rialacháin sábháilteachta don chéad chéim 6.4mm (bearna leictreach), agus ba cheart go mbeadh an fad creepage 7.6mm. (Tabhair faoi deara go bhfuil baint aige seo leis an voltas ionchuir iarbhír, ní mór tagairt a dhéanamh don tábla le haghaidh ríomh sonrach, na sonraí a sholáthraítear le haghaidh tagartha amháin, faoi réir na staide iarbhír)

5. Cold ground and hot ground are clearly marked for the first stage; Ba chóir marc L, N, marc INPUT AC INPUT, marc rabhaidh fiús agus mar sin de a mharcáil go soiléir;

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. I rialacháin sábháilteachta, tuiscint a fháil ar shaintréithe inslithe an áit dhlúth le bord PCB, arb é an áit atá insliú bunúsach, an áit a bhfuil insliú athneartaithe ann, níl an fad inslithe caighdeánach difriúil mar an gcéanna. Is fearr caighdeáin a sheiceáil, agus féadann sé achar leictreach, achar creepage a ríomh.

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. Gaol idir toilleas Y agus sruth sceite agus sruth teagmhála.

Agus mar sin de, míneoidh sé go mion conas an fad a fhágáil, conas riachtanais sábháilteachta a dhéanamh.

6, dearadh PCB ar leagan amach an tsoláthair chumhachta

1. Tomhais ar dtús méid PCB agus líon na gcomhpháirteanna, ionas go mbeidh dlús maith, nó dlúth, tanaí tanaí gránna.

2. Déan an ciorcad a mhodhnú, glac na croíghléasanna mar lár, agus cuir na príomhfheistí ar dtús.

3. Tá an fheiste frith-suite ingearach nó cothrománach, tá ceann acu go hálainn, tá an ceann eile ag feidhmiú áisiúil breiseán, is féidir le cúinsí speisialta tilt a mheas.

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

5. Laghdaigh an limistéar lúb a oiread agus is féidir le linn an leagan amach. Míneofar na ceithre lúb go mion níos déanaí.

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

Seo a leanas an chéad PCB maighdean a tharraing mé, blianta fada ó shin, bhí sé an-deacair a chríochnú, b’fhéidir go bhfuil fadhb bheag sa lár, ach is fiú an leagan amach ginearálta a fhoghlaim:

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. Tá críochfoirt ionchuir agus aschuir socraithe agus ní féidir iad a bhogadh. Tá an bord dronuilleogach.

Anseo tá an leagan amach ó bhun go barr, ó chlé go deas, agus tá an diomailt teasa ag brath ar an mblaosc.

Tá treo sreafa soiléir fós ag ciorcad 2.EMI, rud atá an-tábhachtach, ar shlí eile níl sé álainn agus dona do 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. De ghnáth bíonn an tsraith barr ardchumhachta diúltach, agus téann an bunchiseal dearfach.

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. Léirthuiscint ar shamplaí 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. Tuiscint ar na ceithre lúb de dhearadh PCB: (is é an bunriachtanas maidir le leagan amach PCB ná limistéar beag na gceithre lúb)

Ina theannta sin, tá an lúb ionsúcháin (ionsú RCD, ionsú RC feadán MOS agus ionsú RC feadán ceartaitheora) an-tábhachtach freisin, agus is é sin an lúb a ghineann radaíocht ardmhinicíochta. Má tá aon cheist agat faoin bhfigiúr thuas, tá fáilte romhat iad a phlé. Níl aon eagla orainn roimh cheisteanna ar bith.

9. Spota te deartha PCB (pointe féideartha ar snámh) agus sreang talún:

Ábhair ar gá aird a thabhairt orthu:

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. Tá an lúb a chruthaíonn spotaí te beag agus tá an sreangú gearr, agus níl an sreangú chomh tiubh agus is féidir, ach chomh fada agus is leor an sruth.

3. Ní mór an cábla talún a chur faoi thalamh ag pointe amháin. Téann an príomh-thalamh cumhachta agus an talamh comhartha ar leithligh, téann an talamh samplála ar leithligh.

4. Is gá talamh an radaitheora a cheangal leis an bpríomhfhoras cumhachta.