Darujem 2x nefunkcny PJ 5kW

[mobilik]

Ahojte, darujem dve nefunkcne 5KW Power Jacky, kedze mi uz asi 5 roky doma zavadzaju a lutujem ich vyhodit.

A teraz co im je:

1. PJ mal nehodu a vystrielali v nom tranzistory asi..
2. PJ od nova po 30minutach odpojil zataz a piska ako keby bol pretazeny.

A teraz podstatne, robil som na nich hokusy pokusy. Do druheho menica ktory sa odpajal som vymenil riadiacu dosku z vystrielaneho a aj tak sa nerozbehol, teraz uz hned piska.
Na to treba cloveka ktory tomu viac rozumie ako ja, v takej elektrotechnike som uz ja strateny.

Takze darujem cloveku, ktory ma chut sa stym pohrat a skusit to opravit.
Uprednostnim osobny odber, kedze je to dost tazke, pripadne bude zraz na vychode SK, tak sa to teoreticky moze po niekom poslat.

Ak to niekto opravy tak si narokujem na jedno pivecko.
Víac info v PM.

[rottenkiwi]

Na koľko V je ten PJ ? Koĺko by asi stáli FET-y ? Tie toroidy sú OK ?

[mobilik]

Som aj zabudol napisat. Menice su na 24Vd a toroidy su na 100% funkcne. FETy nemam sajnu kolko by stali...

[Jozef51]

mobilik, taky 5kW PJ by sa mi aj celkom hodil. Skoda, ze som tych 1000km mimo. Dokoncujem dosku menica a jedna z aplikacii by mohol byt napr. vytazovak s premennym vystupnym vykonom 0 az 2500W na komercnom telese 230V/2kW. V ziadnom pripade ich nezahadzuj ak sa nikto neprihlasi z okolia tak nieco vymyslim.
A toroidy 24V sa daju pouzit aj v 48V-ovom menici. Podobne skrina a mozno aj dalsia bizuteria.
PS.: to pivo mas u mna rezervovane, ci uz PJ dorazi alebo nie. Snad mi to buduci rok v Brne vyjde. Kosice su pre mna trochu daleko ale manzelka tam obcas jazdi.

[kodl69]

Mě by se hodily akorát oba ty toroidy, ale mám to dost z ruky. Škoda, že jsi to nevzal do Chudčic.

[rottenkiwi]

Čo z toho je pravda u PJ alebo iných meničov ?

Your high current gate driver chip, and the very low value series gate resistor must create a very low gate driving impedance. Almost nothing should get back onto the gate from the fast voltage transitions on the drain. Gate drain capacitance is much less than gate source capacitance anyway. If the driver has enough current to really hit the gate hard, its going to be pretty effective at shunting away any capacitive coupling back from the drain. Its mainly a problem with very high drain voltages, which our application does not have.

What can be pretty lethal is any series inductance between the gate driver and gate, or in the mosfet source circuit. All of that can only be due to poor circuit layout, and the more mosfets you are attempting to simultaneously drive, the more difficult it becomes to construct a nice tight physical layout with shortest possible tracks.

The ideal system would be one very sturdy driver chip per mosfet, grounded right at the mosfet source with minimum lead length. A series resistor direct from gate driver to gate, and a bypass capacitor right across the dc supply to the gate driver chip. All with the shortest possible track lengths.

You can then be a bit more adventurous with the logic level pwm signal between your IR2110 galvanic isolator, and the various gate driver chip(s). These track lengths should be kept short too if possible, but there is a lot more freedom away from all the extreme switching violence and extreme high current going on right at the mosfet.

A reasonable compromise might be one gate driver chip placed between each pair of mosfets with the gate resistors splayed in either direction to each mosfet. Connection to both sources can be made pretty direct too with a nice wide low inductance solid copper area. The holy grail is all about absolute minimal lead lengths and minimimum inductances.

Transient suppressors right at the mosfet gate are a band aid solution, and if you are going to do it, use 12v or 15v devices, even if your gate is rated to 20v.

The only practical reason for designing and installing a snubber is to move switching losses away from the switching device and into the snubber.
A snubber only really has application for slow switching devices that operate at higher voltages. Say a slow switching bipolar transistor switching 400v at several amps. If there are switching losses that resulted in ten watts of switching loss, you might design a snubber that dissipated 15 watts into a resistor. That removes some of the direct heat burden from the transistor into the snubber. That is the general idea.

Mosfets and IGBTs are so damned fast these days, and switching losses so low, snubbers are just not necessary.

A snubber that actually does something is going to run hot, and that is just a waste of power unless its actually necessary. Snubber design was a serious design skill at one time, and very necessary back in the dark ages when very slow switching devices were all that there was.
The very early days of switching power supplies were a real challenge for even the very best circuit designers because of the crappy semiconductors that were available compared to today.

Today switching speeds are so incredibly fast, snubbers are no longer required.
Its the high switching speeds now, that are themselves causing new and very different problems to the old days.
The problem now is parasitic inductance and the voltage spikes this creates.
Its now physical layout that is absolutely critical to success.

Ok, tak to daj kodlovi alebo jozefovi, oni z toho niečo vyrobia.

[kodl69]

tohle je problém nejenom PJ, to buzení je značně nedostatečný na takovou "baterii" mosfetů, každej s kapacitou 10nF, a je jich 8 paralelně, to ty minitranzistůrky těžko ubudí. To co prodává číňan, EGS8010, IR210 a přímo na 6 mosfetů už je úplná obžaloba. Sice je pam menší impulsní rušení, protože to spíná "naměko" ale mullerova kapacita tolika mosfetů paralelně je taky dost hrozná a asi stojí za koncem nejednoho PJ.
Proto jsme s PavlemR vymysleli moduly, kde je jeden IR2110 a jeden můstek z mosfetů, který se dají poskládat jak je komu libo. Pavel už to má funkční, já pořád jenom na stole...

[Jozef51]

kodl69 neviem, ci rozumiem spravne. Teda jeden modul menica ma budic z 2xIR2110, styri tranzistory v mostiku povedzme IRFP4468 (IRFB4110,...), chladic, el. kondenzatory, keramicke kondenzatory, snimanie prudu a este nieco?

[kodl69]

to je všechno, řízení dělá egs8010. Pavel má svoji desku řízení, já z té z aliexpresu odpáral nepotřebný IR2110 a OZ...
a máme tam IRFP4668 (TO247), asi by mohly být i 4568, hlavně od solidního dodavatele, ne fejky z číny.
Rád bych nějaký sofistikovanější řízení, ale sám to nenaprogramuju...

[Jozef51]

Co sa tyka menicov skusenosti s nimi nemam ziadne. Iba nieco z internetu a firemnych materialov. Zatial jediny zivy projekt (ktory sa nemusi podarit) je prerabka UPS 12V/600W modifikovany sinus na plnohodnotny menic 48V/600W sinus ako zaloznu jednotku pre topeni. Zaklad mam najlacnejsiu cinsku dosku menica (ziskal som cinske schema zapojenia) ktoru samozrejme bude treba doplnit funkcnou ochranou proti skratu a dalsimi 'malickostami' (napr. RC clenmi v mostiku). Ale mohlo by to pracovat aj s dvomi ovladacimi prvkami a to on/off a reset. Ta inteligencia menica by sa zisla... ale ked nie je i tie dva prvky postacia. A vyuzit sa z UPSky da pomerne vela (trafa, skrinka, konektory,...)
Prekvapila ma doska EGS002 tym, ze konstrukter odstavil seriovu komunikaciu a skoro nevyuziva vstup EG8010 na meranie prudu. To je skoda.

[mobilik]

Takže meniče rezervované pre jozef51, na zraze to poriešime.

[JonasPP]

Ak nahodov nebude zaujem o jednu elektroniku z PJ,tak jedna by sa Mi zišla na testovanie,hocktora,fety su to najmenej. A aj uvažujem o prichode na zraz,len momentalne som do 11.9. marod a neviem ako dopadnu testy,čo ma čakaju,lebo ani choroba mi tak nezhumplovala telo ako tie zakerne lieky.

Odoslané z IRON_2 pomocou Tapatalku

[Jozef51]

Re: Darujem 2x nefunkcny PJ 5kW
Příspěvekod JonasPP » pát srp 31, 2018 10:33 pm
Ak nahodov nebude zaujem o jednu elektroniku z PJ,tak jedna by sa Mi zišla na testovanie,hocktora,fety su to najmenej.
Mas SZ.

[mobilik]

Takze pani, zraz sa blizi a na zraze by som odovzdval 2 PJ jozefovi51, ale este prezistujem JonasaPP, len mi nezdviha telefon. Pretoze jemu jeden odisiel, tak si myslim ze by nebolo zle ak by som daroval nejake veci ktore bude chiet jemu a zbytok by potom isiel do Ciech.

Suhlasite?

[mobilik]

Takze nakoniec to bude takto.

JonasPP dostane obe menice. Skusy poskladat opravit. Ak mu zostanu nejake diely tak ich pusti dalej. Trafa chcel kodl69 a nejake dalsie veci Jozef51.

V podstate urcite kodl a Jozef nieco dostanete, len treba trosku este pockat, uvidime co poriesi JonasPP.

Dovoz do Ciech sa poriesi urcite.
Dakujem za pochopenie a dufam ze sa nehnevate.

[Jozef51]

mobilik neposielaj nic. Bez traf to pre mna nema vyznam. Tvoje menice Tvoje rozhodnutie.

[kodl69]

Jestli to chceš zkusit opravit, tak se s tím klidně potrap, a až tě to přestane bavit, tak mám zájem o ty trafa...

[JonasPP]

Tak Ja mam menič u jedneho pana a tak v kutiku duše dufam,že pride na problem a tym padom ani nezadržim tie meniče u seba. Pri najhoršiom to dajak dohodneme.

[JonasPP]

Krasne,jeden PJ som zazrakom rozchodil,len zopar desiatok minut po rozobrati a podla skušania sa rozbehne po oprave fet aj druhy.Uvidime či rozchodim aj môj 6kw bez toho aby som musel rozkuchať jeden 24v. Ten čo ma prestrelene fety ma rovnaku riadiacu elektroniku ako môj,tak uvidim čo sa dozviem pri porpvnavani.

[mobilik]

Som rad ze si to rozchodil aj napriek podcenovaniu ostatných. Teším sa s tebou!