Why so many capacitors to choose from?

MaximRecoil

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I want to replace the electrolytic capacitors (aluminum, radial) on a Double Dragon boardset. So if I select on Mouser.com for example, Nichicon, Aluminum Electrolytic Capacitors, Leaded, Radial, 100 uF 16v; there are 66 results.

Does it matter which one I choose? I see that some are 10% tolerance and others are 20% tolerance. Is 10% always better than 20%? Then there is "Operating Temperature Range". Is a higher temperature rating always better?

So even if I apply a tolerance and temperature range filter, I still get multiple results. Maybe I should just pick the one that they have the most in stock for ... that might mean it is the most popular one.
 
For your board, the 85-degree ones are probably fine. 105-degree ones are good for near power resistors and head sinks, but they don't hurt to be used.

I usually filter by the value and lead (radial or axial), then sort by lowest price to highest. Then if I don't trust the lowest priced manufacturer, I skip down to one I know and trust, and buy those...
 
I tend to buy the highest temp caps and the 10% Just becuase normally the cost is not that much of a factor

I tend to buy Nichicon brands becuase they seem to last longer. I made a lot of money replacing bad capacitors back in the day.

Just my opinion
 
+1
For the most part, any of them will probably work for you. If you're not buying a ton of them get the highest rated ones, because most of your cost will be shipping anyway.

For your board, the 85-degree ones are probably fine. 105-degree ones are good for near power resistors and head sinks, but they don't hurt to be used.

I usually filter by the value and lead (radial or axial), then sort by lowest price to highest. Then if I don't trust the lowest priced manufacturer, I skip down to one I know and trust, and buy those...
 
I usually always try to get 105 degree parts. They tend to be higher quality, and are supposed to last longer. They're a little more expensive, but I figure if I'm spending the time to fix something, I want it to stay fixed.

I usually stock up whenever I buy caps - I'll buy the real common values (1uf@50v, etc) in bags of 100, etc. Notice that on almost all parts, you'll get a price break at a certain point. I fix a lot of monitors, so I like to always have parts on hand. Also, if you have to order a funny value for something - order extra - that way next time this comes up, you'll have spares.

Although, the last time I ordered caps it was over $150 in parts. But, I haven't had to order again in a very long time.

-Ian
 
I usually always try to get 105 degree parts. They tend to be higher quality, and are supposed to last longer. They're a little more expensive, but I figure if I'm spending the time to fix something, I want it to stay fixed.

I usually stock up whenever I buy caps - I'll buy the real common values (1uf@50v, etc) in bags of 100, etc. Notice that on almost all parts, you'll get a price break at a certain point. I fix a lot of monitors, so I like to always have parts on hand. Also, if you have to order a funny value for something - order extra - that way next time this comes up, you'll have spares.

Although, the last time I ordered caps it was over $150 in parts. But, I haven't had to order again in a very long time.

-Ian

I noticed you can go for 105 degrees or 10% tolerance, but not both, at least that's how it was with the types/values I needed. The 10% tolerance ones were all 85 degrees, and the 105 degrees ones were all 20% tolerance. In any event, I went with 105 degree Nichicon wherever I could, but there was one type/value I needed that I could only get from Vishay / BC Components, the Nichicon was out of stock on both Mouser and Digikey:

1000 uF 16v axial, 1 1/16" (27mm) length or less.

I looked for higher voltage rated versions too rather than just limiting the search to 16v but no luck. They were 85 degrees rated too, both the Vishay that I bought and the out-of-stock (until August) Nichicons.

By the way, is there something special about 4.7 uF and its multiples of 10? In this case there are 4.7 uF, 47 uF, and 470 uF capacitors on the boardset; and I think I've come across them in every device I've replaced capacitors in, from power supplies to monitor chassis.
 
By the way, is there something special about 4.7 uF and its multiples of 10? In this case there are 4.7 uF, 47 uF, and 470 uF capacitors on the boardset; and I think I've come across them in every device I've replaced capacitors in, from power supplies to monitor chassis.

Yes. In fact, there is a standard for component values, both resistors and capacitors. Rather than just make every possible part (59uf capacitors, anyone?), there is a set of standard series of components designed to fit pretty much any possible situation, by creating values fairly equally spaced and just within the component tolerances from each other. For example, it would be silly to make both 47 and 49uf caps - the tolerance of electrolytics is 10% at best.

It's known as a "preferred number" series. The most common one, is the E12 series, and contains the following numbers:
10 12 15 18 22 27 33 39 47 56 68 82

Most capacitors and resistors are 10% tolerance, and follow this series.

So that's why so many 47's, 22's, etc. In fact, the most common electrolytics are of the E6 series, which contains only 10, 15, 22, 33, 47 and 68.

Now, they do make parts in inbetween values, and those conform to another series of preferred numbers, such as the E24 series, they're less common - especially for consumer stuff.

Before the modern preferred numbers were used for most component values, you had things like 20 or 50uf caps - which you'll see on equipment from the 70's and before. So, for that stuff, you just pick the closest value - again, the tolerance is 10%, and with the E12 series of parts, you can get within that easily. When you *really* need the precision, other values are available, but they're more expensive and harder to get.

-Ian
 
Yes. In fact, there is a standard for component values, both resistors and capacitors. Rather than just make every possible part (59uf capacitors, anyone?), there is a set of standard series of components designed to fit pretty much any possible situation, by creating values fairly equally spaced and just within the component tolerances from each other. For example, it would be silly to make both 47 and 49uf caps - the tolerance of electrolytics is 10% at best.

It's known as a "preferred number" series. The most common one, is the E12 series, and contains the following numbers:
10 12 15 18 22 27 33 39 47 56 68 82

Most capacitors and resistors are 10% tolerance, and follow this series.

So that's why so many 47's, 22's, etc. In fact, the most common electrolytics are of the E6 series, which contains only 10, 15, 22, 33, 47 and 68.

Now, they do make parts in inbetween values, and those conform to another series of preferred numbers, such as the E24 series, they're less common - especially for consumer stuff.

Before the modern preferred numbers were used for most component values, you had things like 20 or 50uf caps - which you'll see on equipment from the 70's and before. So, for that stuff, you just pick the closest value - again, the tolerance is 10%, and with the E12 series of parts, you can get within that easily. When you *really* need the precision, other values are available, but they're more expensive and harder to get.

-Ian

Very informative; thanks. Information like that makes it easier if you want to stock up on components; i.e. more likely to get useful ones as opposed to ones you'll probably never use.
 
It's known as a "preferred number" series. The most common one, is the E12 series, and contains the following numbers:
10 12 15 18 22 27 33 39 47 56 68 82

Most capacitors and resistors are 10% tolerance, and follow this series.

So that's why so many 47's, 22's, etc. In fact, the most common electrolytics are of the E6 series, which contains only 10, 15, 22, 33, 47 and 68.


-Ian

Each number in this set is roughly 20-22% higher than the previous one. For components with 10% tolerance (+/-), these values cover the entire range for that power of 10.

For a smaller tolerance percentage, you would need more values to cover the range.

It's really pretty neat if you thing about it.
 
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