Where is a good place online to buy capacitors?

R

Rainman21

Limp Gawd
Joined
Aug 23, 2007
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Does anyone know of a place online to buy capacitors at a good price that accepts money orders?
 
The correct ESR depends on several factors. Safest is to replace a capacitor with one as to close to original as possible. Otherwise, you need to know enough about the design to be sure you do not exceed the ripple current rating. In general a lower ESR is better, but not necessarily.
 
Ohms don't apply to capacitors. Farads (or microfarads, or nF, or pF) apply to capacitors. When replacing capacitors, you want the replacement to have a voltage rating at least as high as the old cap's voltage rating. If the capacitor is used in a power circuit (as opposed to a timing circuit), make sure the replacement has the same capacitance or greater (most likely measured in uF) will work.
 
Mohonri said:
Ohms don't apply to capacitors.
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capacitors have inductive and resistive components as well as capacitive. one way the main ohmic loss component is represented is the equivalent series resistance (ESR).
 
mtrupi said:
capacitors have inductive and resistive components as well as capacitive. one way the main ohmic loss component is represented is the equivalent series resistance (ESR).
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You're right, of course, but for just about anything anyone on this forum is going to do, the inductive and resistive components can be safely ignored. I was just making a simplification...
 
What is the capacitor for?

(so I can better answer your question)
 
Mohonri said:
You're right, of course, but for just about anything anyone on this forum is going to do, the inductive and resistive components can be safely ignored. I was just making a simplification...
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No problem. The digikey link had ESR as one of the search parameters so I was just trying to help with how to deal with that. As gee pointed out, more info is needed for a better answer.
 
One is for a bulged motherboard cap between the pci slot and one to replace a bulged cap in a creative subwoofer and other electronics like, speakers, sega gamegear, ect....
 
If you need to replace one cap on that motherboard, it may be worth it to replace them all--they've all been subject to the same conditions, so they're all probably in similar shape.
 
Mohonri said:
If you need to replace one cap on that motherboard, it may be worth it to replace them all--they've all been subject to the same conditions, so they're all probably in similar shape.
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I was worried that the rest would eventually go bad but I was hoping to just replace one. Would it be worth replacing them all on an old socket A compaq motherboard?
 
The badcaps.net site has all the info you need on replacing mobo caps including links to vendors that supply complete reCap kits for mobos known to suffer the badcap syndrome. Plus they can make up kits for any mobo they don't stock one for, and probably at a lower price than one could achieve on his own. The uF value and voltage of the caps are printed right on the side of the originals - no need to guess what you need. 1000 and 2200 uF are typical values for capacitance and 15 or 16V is a typical voltage. Considering shipping, buying and replacing individually makes little economic sense.

.bh.
 
Private_Ops said:
Please explain.
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I think he's referring to 'stiffening capacitors' used in high power car audio systems. Now I don't have any personal experience in this area, but I have my doubts just how useful they really are... Personally, I think there's a lot of snake oil involved. And I'd be curious to see the 'real' capacities of many of these prodcuts being advertised in some kind of test - I get the feeling most don't live up to their marketing.

Wiki said:
Capacitors are used to store extra energy for the amplifier to draw on demand. Capacitors are useful because they can reduce the voltage loss (small margin) on the other electrical components in the car. These large capacitors may not cure headlight and/or interior light dimming as this is a sign of too little amperage from the alternator. A capacitor is only good so far as the audio system isn't trying to pull too much from the electrical system. A capacitor doesn't provide more power, it's designed to 'stiffen' the voltage to the amp, nothing esle. If the current isn't there, a cap won't help. The alternator must have at least 20% more amperage power than the entire vehicle and sound system combined for a capacitor to be of benefit which is ironically the same requirements for an amp to be efficient. A rule of thumb is that 0.5 farad of capacitance is needed for every 500 watts of power in your audio system. A capacitor does not affect sound in any way. IT is strictly for power conditioning.
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The badcap syndrome in Sock A mobos was caused by the mfrs' cutting corners by using off-brand caps and then not doing their due diligence in stress testing a sample of the caps they received. You may still be able to get it fixed by the mfr for free instead of having to do it yourself as it was their fault and most agreed to do the replacements beyond the warranty period as decent caps should easily last 7 to 10 years - as I wrote above, you can find all the info at http://www.badcaps.net . Almost all mfrs of mobos did this to one or more models. Caused mucho loss of face in the mobo biz...
. The newer crop of mobos should be using quality caps so a bulge or leak should be considered a rare lemon and still fixed under warranty. Out of warranty, you'll have to do it, but only the one cap. On the sock A mobos, all the large value electrolytic caps were substandard, so all should be replaced as the arcing leading up to failure puts all sorts of spikes and garbage on the voltage lines that can do damage to other equipment.

.bh.
 
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