Hi I have this circuit from a me welding station that has a burnt capacitor but I don't know the value of it wonder if you can help me? the one that is left has 100uf 50v there is a fuse on the circuit it is ok
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Re: Help me with capacitors replacement
show the back of the board,
there are 2 missing parts i think -
Re: Help me with capacitors replacement
this might help a bit
https://www.reddit.com/r/PCB/comment...ng_components/
and this .. looks like its a bridge rectifier problem .. or something else killed it ..
https://www.reddit.com/r/AskElectron...m_overheating/
google lense seems to be getting better ..Last edited by petehall347; 08-12-2022, 05:40 PM.Comment
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Re: Help me with capacitors replacement
It's not a capacitor, it is a 2W10 bridge rectifier. Here is a picture in case the others disappear in the future.Attached FilesLast edited by R_J; 08-12-2022, 06:17 PM.Comment
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Re: Help me with capacitors replacement
it was a rectifier ..
looks like it needs redesigning to me . its that or needs quality parts .. bridge rectifiers arent fuses or even a good substitute , resistors however ......Last edited by petehall347; 08-12-2022, 06:06 PM.Comment
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Re: Help me with capacitors replacement
I would say it's a crappy soft-start circuit, the big resistor gets bypassed by the triac once the main filter caps are charged up, after the delay.
The board does not look repairable - the bridge rectifier burned up quite badly and the board has too much carbon tracking for mains voltage use IMHO.
If the welder has shorted power components (mosfets, IGBT's) it usually burns up the soft-start resistor so not sure what happened here. The board might have had an arc across the connector/bridge rectifier due to badly designed pc board spacings.Comment
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Re: Help me with capacitors replacement
Thank you all for your quick replies. The circuit looks to be able to be layered it's just dirt on the top part .now the question is what best bridge rectifier that can replace the old one and that might last because I can't find similar in my junkComment
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Re: Help me with capacitors replacement
please show pictures after you have cleaned the pcbComment
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Re: Help me with capacitors replacement
ok i`ll do itComment
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Re: Help me with capacitors replacement
thats a lot better than expected!
but did you find anything else shorted? something else probably caused that.Comment
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Re: Help me with capacitors replacement
i have been told it was a mechanical (machine could no longer feed weld steel) but i don't think so. i will test and see what is broken. but please can you tell me what can i replace the burnt part i mean with something higher value for it to holdComment
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Re: Help me with capacitors replacement
What value of fuse is in the board? The diode 2W10M (2AMP/1KV) should be fine, If this is the wire feed motor drive circuit I would check the wire feed motor etc. for a problem, It may be that the wire feed stopped, and blew the fuse, then someone bypassed the fuse and the bridge and circuit traces burnt up.Comment
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Re: Help me with capacitors replacement
from what i can find about these its happened at least 3 times . its for a cheap welding machine so corners may have been cut building it .Comment
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Re: Help me with capacitors replacement
Check the attached photo, the clearance is a joke!
I would put a regular bridge rectifier like I have shown if there is room for it.
Then remove the traces so the clearance between them is more than a cat whiskers hair!
But you need to triple check my work, it is hard to tell if there are more traces on the top of the board...Attached Files"The one who says it cannot be done should never interrupt the one who is doing it."Comment
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Re: Help me with capacitors replacement
Just noticed your board is unmarked but the one linked by petehall347 in reply #3 has markings on it.
The board is apparently for the wire feeder motor in the welder, and from what others wrote on Reddit it sags so the wire speed is inconsistent.
If you search for these you get lots of hits, seems like a remarkably crap design!
GI-PCB-H59-A0
ZD27223A0
PS: K1 is a: BT151-500R Thyristor (aka SCR)"The one who says it cannot be done should never interrupt the one who is doing it."Comment
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Re: Help me with capacitors replacement
Thank you very much R J, Per Hansson and petehall347. Yes there is room but as you said Per I need to take an extra look at your work. but you say "I would put a regular bridge rectifier" of what value if you were to recomendera?Last edited by bohaboha; 08-14-2022, 06:13 AM.Comment
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