Hallo zusammen,
ich würde hier gerne eine Diskussion starten, warum man beim recappen vielleicht doch keine Kerkos verwenden sollte.
Habe selber schon mehrere Amigas mit Kerkos recapped. Nach einer etwas längeren Diskussion mit Chucky (John Hertel), rät er dringend davon ab, nachdem ich ihm erzählt habe, dass ich für nalkem demnächst mehrere Amigas recappen werde.
Da ich leider nicht gerade der beste Elektroniker bin, würde ich hier gerne einfach mal darüber Diskutieren. Chucky versteht nicht, warum wir hier in Deutschland so sehr auf Kerkos stehen. Überall anders würden diese beim recappen nicht benutzt ! Ich würde gerne auch von den Elektronikexperten hier im Forum die Meinung dazu hören, da ich es schon für ein sehr wichtiges Thema halte.
Anbei einige Ausschnitte aus dem Chat mit Chucky (Meine Englisch Fehler habe ich jetzt mal korrigiert, damit es nicht zu peinlich wird)
(Und auch ein bisschen auf das wichtigste gekürzt) (P.S.: Habe die Erlaubnis teile des Chats zu veröffentlichen)
Ich denke einer der wichtigsten Aussagen: "do not change type.. change quality"
Vorausgehend habe ich ihm erzählt, dass ich demnächst einige Amigas von nalkem recappe, daraufhin ging es dann so weiter:
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Chucky:
do not do the "german" way of recapping
Ich:
hehe.... at a1k.org they all do the "german" way And I think my friend wants the "german" way, because everyone is talking about "ceramic capacitors"....
It would be hard for me to convince him not to use ceramic capacitors.....
Chucky:
siigh.. use resistors while doing it wrong anyway
Ich:
Would be cool if you would make a new topic at "a1k", why its not good to use "ceramic cons".. So i would have a pros and cons list to show it to my friend
hehe....
Chucky:
nahh..
Ich:
I think they have all fear, because not using ceramics could mean again leakage in 10-20 years.... ? maybe this is the important point of the germans ?
Chucky:
the caps I am using will not leak for 40-50 years
thing is that ceramics change capacitance depending on the voltage..
they are usually 50V meaning a 22uF 50V ceramic will be 22uF when it gets 50Hz. amiga uses like 5. then it wil be maybe 10uF instead
they basically behave different. and that "doesn't leak" shit is as people tend to use cheap-ass components
commodores caps was rates 1000hrs at 85 degrees, those I use is 10000hrs ay 105 degrees
everytime I recap an CD32 I am thikning: this is proof od different behaviour. as why do they have ONE tantal but not the rest. as. there is a reason.
same for A3000. why is there ONE tantal (specificly mentioned in schematics) but not the rest. they are electrolytes.
Ich:
Okay...
Chucky:
but it is strange that the germans go so hard for ceramics. but "the rest of the world" refuses it
do not change type.. change quality
but I have talked to alot of persons doing HW devs etc. they have given me pretty good explanations..
why changing is a bad idea..
there AREplaces that can be ok. but unless you designed the damnthing. you do not reaally knw
just think of. IF ceramics would always be a good replacement. WHY even produce electrolytes?
https://electronics.stackexcha…ngible-differences-in-use
This is also not a trivial effect. A 1210 10µF 50V ceramic capacitor, a veritable beast of a capacitor, will lose 80% of its capacitance by 50V. Some are a little better, some are a little worse, but 80% is a reasonable figure. The best I have seen was a 1210 (inches) keep about 3µF of capacitance by the time it hit 60V, in a 1210 package anyway. A 10µF 1206 (inches) sized 50V ceramic will be lucky to have 500nF left by 50V
Class II ceramics are also piezoelectric and pyroelectric, though this doesn't really impact them electrically. They have been known to vibrate or sing due to ripple, and can act as microphones. Probably best to avoid using them as coupling capacitors in audio circuits.
last sentence.. and people use them JUST there..
but they doesn't leak
A4000 pictyrie coming up:
Ich:
WTF happened there ?
Chucky:
normal ceramic cap failure
Ich:
Used wrong one ?
Chucky;
no. it just got bad
original 220nF cap on an A4000
Ich:
Wow.... Heavy damage ! Never seen that ceramics can make so much damage !
Chucky:
well.
they doesn't leak
they BURN
tantals doesn't leak
they EXPLODE
Ich:
Leakage vs. burn vs. explode......
Chucky:
yes
Ich:
okay... than leakage is the fewer problem....
Chucky:
but yes. it is a mystery why germans accept this. it is soo damn strange for me
yeah,,
let me say like this: if anyone have ANY issues building an ReAmiga 1200 orso. using ceramics instead of electrolytes I will refuse to support them- also mentioned in my build-text
wekll as they still manufacture different types.. they do it for a reason and THAT should be reason enough for most people
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So. Würde mich über eine rege Diskussion über dieses Thema freuen....
