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Capacitor question

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lurkepus

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Hi
I'm doing a repair on a LCD monitor , i need to change a few caps in the psu i noticed that on of the cap is a 470 uF 25 volt cap i have orderd some 470 uF 50 volt caps for another project and wonder if i can use those instead of the 25 volt one.
 
Yes, you can go higher with the voltage on a cap, higher with the current on a coil, and higher with the wattage on a resistor.
 
There's a couple of other things I probably should have warned you about - first is obvious: check the mechanical data and make sure it physically fits.

Second is a little more subtle: if it's in a switching power supply, there's a good chance you will want a "low esr" cap. Check the letters stamped on the side, there will be one to four letters in a group by themselves. You don't want to replace an AFK series with an M series, for instance. You can go lower with esr (or higher with the "ripple current") than the one you have.
 
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ok i have a cap here marked CD11X anand one marked C632 (it has anoter 2 letter combination KF) can i use the CD instead of the C (KF) type ???
 
one more question what are the difference between the diffrent series and how many are there ??
 
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Lots of different series, but most of the differences are unimportant for this (mainly operating temperature ranges). Unfortunately, I'm not seeing any of those letters. Is that cap in the fluorescent lamp supply or the audio amp section? If so, just use the one you have.
 
It's in the main power supply .. and i got the monitor up n running however ther are some humming noice but not as much as right befor the monitor went dead.. i guess i have to change a few more caps :)
 
A bad cap can certainly cause humming.

These are aluminum electrolytics, right? Metal cylinder with a plastic sleeve? Was the safety vent (a couple of scored lines on the end) popped .open?

Main thing is just to get a low-esr replacement if it's the switching regulator. Try DigiKey or Mouser, they have nice abilities to sort through huge numbers of different caps by size, voltage, esr, etc.
 
A bad cap can certainly cause humming.

These are aluminum electrolytics, right? Metal cylinder with a plastic sleeve? Was the safety vent (a couple of scored lines on the end) popped .open?

Main thing is just to get a low-esr replacement if it's the switching regulator. Try DigiKey or Mouser, they have nice abilities to sort through huge numbers of different caps by size, voltage, esr, etc.
yes they are .. on the monitor i have fixed one cap had almost popped and there are bulges in 3 caps on the other monitor so they were easy to spot.

since i'm really new to electroncis i have bought most parts of Ebay , i know they might be grey marked part with a lower quality but i guess they will do for now .. ofcause i will use genuine parts when i get past the exprimental stage but Ebay parts is less expencive to replace in case i mess up :)
 
X Y and Z series caps are designed for line voltage applications and thus it's part of where on the AC line they may be used. If that's the case, you cannot substitute.

Some metal oxide or flameproof resistors should not be upped in wattage because they were designed as "fuses".
 
^ You are confusing two very different things. The ones you are talking about are square polyester line filter caps, are never much over .47µf, and have voltage ratings in the hundreds of volts. Lurkepus' caps are cylindrical aluminum electrolytic DC filter caps, with values in the hundreds of µf, and a voltage rating of 25V.
 
i might have mixed up some terms but the one i desolderd from the psu was a 1000uF 16 vol cylindrical aluminium electrolytic capacitor :)
 
Not you, KeepIt is talking about something completely different.
 
^ And also, as you can see, these are not the kind of capacitors lurkepus is talking about. These are nonpolarized poly line filter caps with low capacitance, high voltage ratings, and completely different construction. Lurkepus has polarized aluminum electrolytics with high capacitance and low voltage.
 
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