I found the bad cap, looking at replacements

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  • kaboom
    replied
    Re: I found the bad cap, looking at replacements

    Originally posted by evilkitty
    When i say safety i mean for the intended load not me, is there anything i can add on either the dc or ac side of the circuit?
    Yes! An equipment grounding conductor (EGC), from DC common to the "third wire" of your (new) power cord. Your line voltage is 120, so for a 200V input filter, use Nichicon CS.

    Connect line & neutral from the cord to the fused & unfused (respectively) AC inputs on that PCB. Connect the green or green/yellow wire from the line cord to the "-" pin on the first filter cap after the transformer/rectifier on the secondary side.

    So if/when it shorts pri-sec, the fuse blows and/or bkr trips, if fault current gets into bkr's instantaneous range. Instead of the output sitting at line voltage, with the connected load still working, it's made safe and the input to the supply is killed.

    Let me add that those supplies are kind of flopping loose in that case- at least move them outside. Those little supplies, not that I'd use them personally, can be just as nasty as bigger ones, like what was in that case originally. Don't let their small physical size or capacity be mistaken for small hazards.

    After looking at this, I think you'd be better off with an external "brick" supply connected by a cable and multipin plug/receptacle.
    Last edited by kaboom; 11-23-2017, 05:51 PM.

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  • evilkitty
    replied
    Re: I found the bad cap, looking at replacements

    When i say safety i mean for the intended load not me, is there anything i can add on either the dc or ac side of the circuit?

    as for the pictures of the 12v adapter:
    https://imgur.com/a/ps6uA

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  • budm
    replied
    Re: I found the bad cap, looking at replacements

    "So assuming the transformer fails and allows ~170v to go through is there a fuse i can put in the output line to act as a safety? i would say a fuse of about 1.5A should be fine"
    re you talking about putting a fuse on the DC output of the power supply?
    If that is the case it will not protect anything if the transfomer insulation failed, you will likely to get electrocuted, the fuse on the DC output is not going to do anything.

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  • evilkitty
    replied
    Re: I found the bad cap, looking at replacements

    So assuming the transformer fails and allows ~170v to go through is there a fuse i can put in the output line to act as a safety? i would say a fuse of about 1.5A should be fine
    I know i would want a fast blow, but i do not know what the difference in between glass and ceramic, well i know what they are but i do not know why it matters in a fuse

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  • evilkitty
    replied
    Re: I found the bad cap, looking at replacements

    Originally posted by sam_sam_sam
    Would it be easy to take a photo of the 12 volt & 5 volts power supply board I am curious of the quality of that power supply seeing the quality of the 5 volt board is to me is crap

    Just a thought
    The 12v adapter is from networking hardware that my ISP uses, so it should be a decent unit, based on the math i did, but i do stress it at times, probably about a 95% load; that is a 1A supply; it will put out some heat under that load
    that unit is running my network switch and powers my keyboard light (SMD 3528 led strip), i think i used a TIP120 transistor to turn it on/off
    but yes i can take a pic for you, easier now then back when i took that last photo, i have space connectors on the mains power lines now and there is a molex plug on the DC side, i can do so this afternoon
    Last edited by evilkitty; 11-23-2017, 10:39 AM.

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  • Per Hansson
    replied
    Re: I found the bad cap, looking at replacements

    Originally posted by evilkitty
    @stj you hit the nail on the head with the brand part (Changx)

    I have 2 questions about the series
    1. do you have a link to what each means/ intended use
    2. which series do i want for each cap

    I do have 3 of these units (replacing caps in all), 2 have the same garbage caps, one has different caps, the other has Jwco, the larger 10uf caplooks to have a actual number on it (CD11G brand appears to be jw)
    CD11G looked familiar, read this thread for a laugh
    https://www.badcaps.net/forum/showthread.php?t=47823

    Originally posted by evilkitty
    @Per Hansson
    After looking at that cap, wouldn't this one be better/last longer?
    https://www.mouser.com/ProductDetail.../EEU-FR1E471Y/
    Sure, was just trying to keep close to the dimensions you stated.


    Originally posted by evilkitty
    and about that 400v cap, does that need to be fr as well?
    i had this in my cart, i know it is only rated at 160v, but it should only be getting used at ~125v
    https://www.mouser.com/ProductDetail...47-UCA2C100MPD
    Never ever do that as budm stated!!!
    You can use any 400v rated cap you find on your favorite shopping site, it really does not matter. (It does not have to be low ESR).
    EDIT: This one is nice, maybe it was already linked before:
    https://eu.mouser.com/ProductDetail/...5TgiW03dbXY%3d
    Last edited by Per Hansson; 11-23-2017, 09:55 AM.

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  • sam_sam_sam
    replied
    Re: I found the bad cap, looking at replacements

    Would it be easy to take a photo of the 12 volt & 5 volts power supply board I am curious of the quality of that power supply seeing the quality of the 5 volt board is to me is crap

    Just a thought

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  • evilkitty
    replied
    Re: I found the bad cap, looking at replacements

    While i do agree with that, but with how i am using the one that failed, that very nice unit is a bit large to fit in addition to being overkill
    https://i.imgur.com/CyOkW3C.jpg
    i have a 12v and 5v adapter in there

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  • kc8adu
    replied
    Re: I found the bad cap, looking at replacements

    even fc will do on the output.
    eb are fine on the input.
    since i stock fc to simplify stock i use them for the startup.
    they always work.
    if you got hot output caps in 60sec they are backwards or rectifier leaky.
    digikey offers usps 1st class and i dont mind the big flat box small orders come in.
    great for shipping tcon,mains,frc,ect.
    i reuse them.
    agreed on that being a shit power supply.and a transformer failure may make the output live with line voltage.
    Last edited by kc8adu; 11-23-2017, 09:13 AM.

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  • sam_sam_sam
    replied
    Re: I found the bad cap, looking at replacements

    Originally posted by evilkitty
    I want to replace the low quality caps in the 5v 2a adapter my rpi uses (I did make sure it can do 2A, not sure how long it can handle it with how hot the 470uf caps get, but it did so with 0 vdrop; that test was done with 18awg wire soldered to the board, not over a micro usb plug)
    it had 2 caps fail, both are 470 uf 16v, they are by far the hottest running component in the unit
    they lasted about 1.8 years

    First of all to me this a garbage power supply I would just take the low voltage power supply cord off of it and use this power supply after you replace the caps inside of it is very easy it has one screw that hold it together

    Here is the link where you can buy one
    One note every so often they run a sale on these power supply for $5.00 each some times they have a limit to how many you can buy and sometimes do not

    http://www.goldmine-elec-products.co...?number=G20394

    If you want to see the inside of this power supply look at this post at the top of the page

    https://www.badcaps.net/forum/showth...t+Power+Supply

    One thing that nice about this power supply is that it has an adjustment for the output voltage

    The range is 4.75 to about 5.75 volts

    I use this power supply for all of phones and tablet it works very good and this power supply run cool when pushing 2 amps while I am on my tablet surfing the web and charging the battery

    I have pushed this power supply to 4.5 to 5.0 amps and dose get a little warm to touch
    Last edited by sam_sam_sam; 11-23-2017, 09:11 AM.

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  • evilkitty
    replied
    Re: I found the bad cap, looking at replacements

    sadly mouser does not carry rubycon
    i ordered from digikey once but they charged me way too much in shipping, they sent be a box full of packing paper, almost entire cubic foot of it
    *looks at life span *

    if i use mouser i guess that limits me 1 one of these 2 with only about 1/2 the life
    https://www.mouser.com/ProductDetail/647-UCY2G100MPD (400v Nichicon)
    https://www.mouser.com/ProductDetail...XG201ELL100MJ1 (200v United Chemi-Con)
    Last edited by evilkitty; 11-23-2017, 08:26 AM.

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  • stj
    replied
    Re: I found the bad cap, looking at replacements

    for the 10uf,
    i'd use rubycon LLE series 10uf 250v (on 110v mains only!!)
    that range is intended for led lamps and has incredible rated lifetime!
    i use them in my radio chargers.
    Attached Files

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  • budm
    replied
    Re: I found the bad cap, looking at replacements

    You cannot go wrong with PANASONIC caps FR, FM series .

    'and about that 400v cap, does that need to be fr as well?
    i had this in my cart, i know it is only rated at 160v, but it should only be getting used at ~125v'

    https://www.mouser.com/ProductDetail...47-UCA2C100MPD.
    Nope, do not using 160VDC cap! the dcV on the cap after the rectification is about 120VAC x 1.414 = about 170VDC!, they use 400VDC cap because that adapter is probably made to handle 230VAC as well. Never go lower Voltage than the original.
    Last edited by budm; 11-22-2017, 10:44 PM.

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  • evilkitty
    replied
    Re: I found the bad cap, looking at replacements

    the transformer seemed warm, but those 470uf caps were cookin and it was not a very long test, maybe 60 seconds
    for actual use this board is only outputting 0.5A and at most 1A or 0.5+ what ever it takes to charge a old 2ed gen ipod shuffle
    Last edited by evilkitty; 11-22-2017, 09:21 PM.

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  • kaboom
    replied
    Re: I found the bad cap, looking at replacements

    Check temp rise on that little transformer- bet it's cookin' at 2A out w/o the PCB in the enclosure.

    Sorry to say that looks like lots of cheep "fone chargers" I've EOLed. That has potential to kill if the transformer overheats and shorts pri-sec. It'll keep working with 5V across the output leads while line voltage is present to external GNDs, including YOU.

    R- PI is the next frontier in cheep POS supplies, after gray/black market tablets/ fones & aftermarket chargers.

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  • evilkitty
    replied
    Re: I found the bad cap, looking at replacements

    @stj you hit the nail on the head with the brand part (Changx)

    I have 2 questions about the series
    1. do you have a link to what each means/ intended use
    2. which series do i want for each cap

    I do have 3 of these units (replacing caps in all), 2 have the same garbage caps, one has different caps, the other has Jwco, the larger 10uf caplooks to have a actual number on it (CD11G brand appears to be jw)

    I have not replaced any caps yet, all i did was swap a in a spare board
    the original caps run hot, but to be far the adapter puts out 5.25v and i used 2.4 Ohms (5 Ohm 10% 10W x2) resistance and it did maintain 5.25v and it is rated (more accurately labeled) at 2A
    we all know anyone using knockoff/fake caps does not care how long the unit last

    I want to make sure i get the correct/best caps

    @Per Hansson
    After looking at that cap, wouldn't this one be better/last longer?
    https://www.mouser.com/ProductDetail.../EEU-FR1E471Y/

    @stj
    as for the 47uf cap, this is the only one matching what you would use:
    https://www.mouser.com/ProductDetail...67-EEU-FR1H470
    It is a tad wider but i think it will fit

    and about that 400v cap, does that need to be fr as well?
    i had this in my cart, i know it is only rated at 160v, but it should only be getting used at ~125v
    https://www.mouser.com/ProductDetail...47-UCA2C100MPD

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  • stj
    replied
    Re: I found the bad cap, looking at replacements

    your wrong because the idea is NOT to have to fix it again later.
    i would use a 47uf 35v/50v panasonic FR in it.

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  • NeedsMoreFlux
    replied
    Re: I found the bad cap, looking at replacements

    I know others on here disagree, but I don't think it matters which brand you use. especially on cheap chinese parts like this.

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  • NeedsMoreFlux
    replied
    Re: I found the bad cap, looking at replacements

    I think if you use caps that are physically larger then they will be able to handle more current with less heat.

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  • jazzie366
    replied
    Re: I found the bad cap, looking at replacements

    Originally posted by stj
    5mm 47uf having "specs"? you must be joking - it's going to be a chang/chong/cheng-x type junk.
    All those caps are fake Chongx or Chengx caps. The print is wrong, there is no series denotation and there is no lot number. They're blatant fakes. I've found fake ChengX/ChongX etc in many power supplies that were branded and UL listed etc. Obviously they were lower end ones, but nonetheless they'll still make it.

    The fakes fail a lot sooner than the real ones, Chong and ChongX are spinoffs of the actual caps ChengX and Chang which ChengX being made by Bentex and Chang being made by Yang Chang.

    Oh yeah, keeping in mind that they're fake. I found out fake caps are usually highly deprived of electrolyte. They reduce the amount to reduce costs, this is easily seen by taking a fake and a real and opening the fake one and the real one. The real will have much more electrolyte than the fake. The fakes also commonly have a very clear, (sometimes) odorless electrolyte.
    Last edited by jazzie366; 11-22-2017, 03:03 PM.

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