I te korero mo te raru uaua o te whakawhiti hiko, 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: Te mahi hiko, te ara hātepe, nga whakaritenga haumaru, te paanga a te EMC, me era atu. I roto i nga waahanga e whakaarohia ana, ko te hiko te mea tino nui, engari ko te EMC te mea uaua ki te maarama, a ko te pounamu o nga kaupapa maha kei te EMC. Ko nga korero e whai ake nei mai i nga tohutohu 22 hei tohatoha i te papa PCB me te EMC.

1, ka taea e te huringa paari te waatea PCB hoahoa EMI ara iahiko

Ko te paanga o te ara iahiko i runga ake nei ki te EMC ka taea te whakaaro, kei konei nga taatari whakauru; Lightning-proof pressure sensitivity; Te ātete R102 ki te aukati i te ohorere o te wa (me te relay hei whakaiti i te ngaronga); Key error mode X capacitance and Y capacitance with inductor filtering; He kohinga e pa ana ki te poari ahuru; Ko enei taputapu he mea nui, a, me aata aro nui ki nga mahi me nga mahi o ia taputapu. 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. Huringa me te EMC: (ko te tuhinga matua o te flyback tino mohio, tirohia ko nga waahanga matua o te ara iahiko kei roto te tikanga 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. Engari ma te huri o te hiko e whakaputa te papa aorangi e rereke ana, a ma te rereketanga o te papa aukume e ahei ai te whakaputa i te papa hiko (ina hoki, koinei te whika Maxwell rongonui a kei te whakamahi au i te reo maamaa), a ma te rereketanga o te papa hiko ka taea ano te whakaputa i te aukume mara. Na kia mahara koe ki nga waahi kei reira nga whenua kei runga / whakaweto ranei, koina tetahi o nga puna o te EMC, ana koinei tetahi o nga puna o te 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! Ko etahi atu koropiko e rua nga koropiko ngongo me nga koropiko whakatika, kia maarama ki mua, katahi ka korero!

3. Te hononga i waenga i te hoahoa PCB me te 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. Ko te waahanga hangahanga, kaore i te pai te papaaho hoahoa radiator ka pa ki te papa o te momo whakangungu rakau;

4. Mena he tata rawa te waahanga taangata ki te puna whakararu, penei i te ara EMI me te ngongo whakawhiti, ka kore e kore ka mate te EMC, a me tino marama te waahanga wehe.

5. Waea taera o te korowhiti ngongo RC.

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

Ka korero ahau mo tenei, ka nui ake aku korero mo tenei, engari ka riro maau e arahi.

Here’s a quick example:

Ka rite ki te whakaatu i te pouaka kiko i te ahua i runga ake nei, kua whakauruhia te waea waea waea X capacitor. Ka taea e koe te ako me pehea te hanga i nga waea waea pou whakahoahoaho ki waho (ma te whakamahi i nga waea hiko oini) Ma tenei, ka taea e te hua taatari o te X capacitor te eke ki te ahua pai.

4. Te whakarite mo te hoahoa PCB: (mena kua tino rite koe, ka taea e te hoahoa te pumau i tetahi taahiraa kia kore e huri te hoahoa ka tiimata ano)

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. Tukua te huarahi ara: ko te roopu rarangi kotahi te kowhiringa poari, ko te papa papanga-maha, e ai ki te hoahoa huahua me te rahi o te poari, te utu me etahi atu arotake aro matawai.

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. Ko te tawhiti o te papa whakauru whakauru he nui ake i te 3.0mm e hiahiatia ana e nga ture ahuru, a ko te pereti pono he 3.5mm (he korero noa, ko te tawhiti o te ngongo o te fuse he 3.5mm i mua me te 3.0mm i muri).

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. Ko nga ture ahuru mo te waahanga tuatahi e tika ana kia 6.4mm (waahi hiko), me te 7.6mm te tawhiti o te kaahu. (Kia maarama e pa ana tenei ki te ngaohiko whakauru pono, me titiro ki te teepu mo te tatauranga motuhake, nga raraunga kua tohaina mo te tohutoro anake, kei raro i te ahuatanga tuturu)

5. Cold ground and hot ground are clearly marked for the first stage; L, N tohu, INPUT AC INPUT tohu, tohu whakatupato fuse me etahi atu me tino tohu;

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 nga ture ahuru, kia maarama ki nga ahuatanga aukati o te waahi tata me te poari PCB, ko tehea te waahi paraoa, ko tehea te waahi whakakaha, he rerekee te rereketanga tawhiti kaore i te orite. He pai ake te tirotiro i nga paerewa, ka taea te tatau i te hiko hiko, te tawhiti mamao o te 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. Te hononga i waenga i te kaha o te Y me te turuturu o naianei me te waa whakapiri.

Ana, pera tonu, ka whakamaarama taipitopito me pehea te waiho i te tawhiti, me pehea te mahi i nga tikanga ahuru.

6, hoahoa PCB mo te whakatakotoranga mana tuku

1. Tuatahi te mehua i te rahi o te PCB me te maha o nga waahanga, kia tutuki pai ai te kiato, kia matotoru ai ranei, ka kino te mokowhiti.

2. Whakataurite te ara iahiko, tangohia nga taputapu matua hei pokapū, ka tuu i nga taputapu matua ki te tuatahi.

3. Ko te taputapu he poutū whakapae whakapae ranei mo te tuunga, he ataahua tetahi, tetahi he watea-ki te mahi, ka taea e nga ahuatanga motuhake te whakaaro he monga.

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

5. Whakaitihia te waahanga koropiko i te waa e taea ana i te wa o te whakatakotoranga. Ko nga koropiko e wha ka whakamaramatia taipitopito a muri ake nei.

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

E whai ake nei ko te PCB wahine tuatahi i kumea e au, i nga tau kua hipa, he uaua ki te whakaoti, tera pea he raru iti kei waenga, engari ko te whakatakotoranga whanui he ako nui:

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. Ko nga taunga whakauru me nga putanga whakaputa kua pumau, kaore e taea te neke. He tapawhā rite te papa.

Anei te whakatakotoranga mai i raro ki runga, mai i te maui ki matau, a ko te tohatoha wera kei i te anga.

2. Ko te ara iahiko he maarama tonu te ahunga rere, he mea tino nui, mena kaare he ataahua me te kino ki te 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. Ko te papa o runga o te mana nui te tikanga ka kino, a ko te papa o raro ka pai.

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. Mauruuru ki nga tauira 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! Kei muri hoki ma te poari nei e whakamaarama nga akoranga, i pai ta maatau tuatahi.

8. Te maarama ki nga koropiko e wha o te hoahoa PCB: (ko te hiahia matua mo te whakatakotoranga PCB ko te rohe iti o nga koropiko e wha)

Hei taapiri, ko te korohutu mimiti (te ngongo RCD, te ngongo RC o te ngongo MOS me te ngongo RC o te ngongo whakatata) he mea tino nui, koinei hoki te koropiko e whakaputa ana i te hihi auau teitei. Mena he paatai ​​taau mo te ahua o runga ake nei, me pai ki te korero mo enei mea. Kaore matou e mataku ki nga paatai.

9. PCB hoahoa waahi wera (waahi tupee) me te waea whenua:

He mea nui e hiahiatia ana:

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. Ko te koropiko i hangaia e nga waahi wera he iti nei, he poto nei nga waea waea, a, kaore i te rite te matotoru o nga waea waea, engari mena ka ea te waa.

3. Me taura te taura whenua i te waahi kotahi. Te whenua mana matua me te tohu whenua wehe, wehe te whenua tauira.

4. Ko te whenua o te radiator me hono ki te whenua mana matua.