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 Rdeč kitajski kondenzator

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Avtor: igo,  PrispevekObjavljeno: Ned Okt 30, 2011 4:09 pm    Naslov sporočila:  Rdeč kitajski kondenzator
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... da boste vedeli, zakaj imam alergijo na rdeče kitajske kondenzatorje ...

Ko prebijejo, gredo v kratek stik.

Posledično skurijo vse, kar bi se skurilo, če bi v vezju na njihovem mestu napravili kratek stik.

Na sliki je primerek iz pištole za vroči zrak. Ne le, da je nastal kratek stik, njegova vsebina je celo ekspandirala, prebila ohišje in se v obliki prevodne ogljene pene razlila.
Preko njega se v nadaljevanju napaja 17VDC motor. Ko je kondenzator prebil, je odpovedal motor, takoj za njim pa še grelec (ni bilo odpihavanja toplote).
Avtor: Azrael, Kraj: Gorje PrispevekObjavljeno: Ned Okt 30, 2011 10:09 pm    Naslov sporočila:  
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To čudo tehnike nima upora, ki pregori, če gredo v maloro kondenzatorji za omejitev toka? Razen, če gre samo za filter proti RF motnjam?
Avtor: ElGrigon, Kraj: okolica Lenarta PrispevekObjavljeno: Ned Okt 30, 2011 10:30 pm    Naslov sporočila:  
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Ti njihovi kondiji so nekam čudnih dimenzij. Enkrat sem iskal ekvivalent in v takem rastru sploh nisem dobil nikjer. Tako, da verjetno pretiravajo z DC voltažo in ga zaradi tega potem raznese.
Avtor: igo,  PrispevekObjavljeno: Ned Okt 30, 2011 11:23 pm    Naslov sporočila:  
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Tavečji kondi je dolg cca 33mm, visok cca 25mm in širok cca 15mm, raster cca 30mm. LGU805K 400MER .
Manjši je dolg cca 33mm, visok cca 20mm in širok cca 10mm, raster cca 30mm. LGU475K, 400MER .

Mali je za I hitrost, večji za II hitrost, skupaj vzporedno sta za III hitrost. Gre za klasično R+C vezavo, kjer je del R kar motor znotraj graetza (4x 1N4001, so ostale cele), C pa je za omejitev toka skozenj. Še dva 25ohm upora poleg kondijev sta vezana zaporedno k njima.

Motor sem celo usposobil, je nastal le medlamelni stik, grelcu pa je odletela termična varovalka česar prej zaradi nedostopnosti nisem opazil. Dva upora za omejitev toka skozi motor sicer obstajata (nekaj modrega znotraj termoskrčljive cevke), verjetno sta preprečila popolno uničenje komutatorja ali navitij.

Ko dobim nove PP folijske kondije tipa X2, bom zadevo celo usposobil.

Ta rdeč tip kondijev je zaenkrat edini, ki jih bom počasi začel preventivno menjavati že pri novih napravah. Doslej so bili v primeru okvare nekega vezja krivi povsod, če so le bili prisotni v njem.
Avtor: urosr, Kraj: Velenje PrispevekObjavljeno: Sre Jan 11, 2017 3:28 pm    Naslov sporočila:  
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In kaj si ugotovil, sam iščem tak kondenzator, pa zaenkrat ni neke sreče Smile
Avtor: Keporkak,  PrispevekObjavljeno: Pet Nov 02, 2018 1:05 pm    Naslov sporočila:  Capacitor
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Hi guys,

I am sorry that I write in english (I am from Czech, I beleive you would not understand even when I am also Slav Smile But I need value of resistor from first post. I have similar hot air gun Phlg 600, Resistor, which is blown on first image (between caps) I have 27kOhm (measured 33kOhm). But I am not able to read color code from given photo (as I am not active user...) My resistor is blown so it has no markings now, only black smoke.

So Its strange, that Igo wrote about 2 resistors, where both have only 25 Ohms.

Can somebody please send me photo in full size to my e-mail? novak.to at gmail.com

Thank you very much in advance!

Tomas
Avtor: cici, Kraj: Trbovlje PrispevekObjavljeno: Pet Nov 02, 2018 1:31 pm    Naslov sporočila:  
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Če je to enako vezje kot na tej povezavi: http://legnofilia.it/posted_img_thumbnail.php?pic_id=http%3A%2F%2Fwww.legnofilia.it%2Ffiles%2Fposted_images%2F81%2Fcimg3166.jpg potem je upor 15 Ω.
Avtor: igo,  PrispevekObjavljeno: Sob Nov 03, 2018 2:32 am    Naslov sporočila:  
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Huh ... Sad
Sorry, that I took so bad photo. I am not able to read colours from the picture, it is too blur. I can see Brown, Green, Green and tolerance Anxious , and I am not sure any more about which resistor(s) I was writting about.
But there are also 4 diodes and other 2 elements that are not visible on this picture.

I wrote:
Capacitor and Resistor are connected in serial are used for limiting current and voltage of DC motor.
R1 in serial to smaller C1 for speed 1
R2 in serial to bigger C2 for speed 2
For speed 3 there are ((R1 serial C1) parallel (R2 serial C2)).


It would be easier to evaluate R if you could draw a circuit sketch (at least the PCB), just to see if R and C are connected parallel (high resistance) or serial (low resistance).
It is also possible that 1M5 resistors are used for discharging foil capacitors, which could otherwise stay charged and dangerous for very long time. And low resistance resistors are used to limit motor current.

Check motor voltage, run it on external DC voltage source, measure current and reverse calculate resistors (I hope you know values of both C). R are mainly for antisurge purpose so no exactly original values are necessary. Majority of the job is done by C.
You can find formulas for impedance if google: LED on 230 V
Just insert measured current and voltage.
Avtor: igo,  PrispevekObjavljeno: Sob Nov 03, 2018 2:59 am    Naslov sporočila:  
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And yes, .. during writting this post I was charging my old Nokia 6680 and now I checked Gallery and unfortunately original picture does not exist any more. There are just many other pictures from 2006 to 2012 on it
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