Best Capacitors

I'm going to be buying some capacitors and was wondering which ones were best. Ceramic or Electrolytic?


Your capacitor selection depends entirely on it's role in the circuit. Different ones are best for different applications, that's why there's so many! I'm sure one of the senior members here would elaborate further on which types are most used for what. What circuit are you using them in?

I'm using them to filter out noise for an analog input.

Given the options I’d go with ceramic there :slight_smile:


Where would you buy from? Spark fun does not have any.

Any of the big-name retailers really... Farnell, RS, DigiKey etc. Or, if I just wanted a cheapo bumper pack of different values I might order from one of eBay's HK-based sellers.

You may be able to pick up something like this but bigger, for a lot less money, if you don't mind waiting a few weeks for it to arrive.

Thanks. I think I will look for a kit.

What size capacitors should I look for?

Thanks, Drew

100nF is a good value. It depends on the frequency of the input signal though, since by design it forms a lowpass filter.

Just get a ton of different values, then you'll be sorted out for all kinds of experimenting!

I was looking at digikey, but they had everything from .011uf to 680uf. I would be broke if I ordered some of each! What is the range I would be using for general Arduino use?


Just be thankful your not trying to enter into the world of 'golden ear' audiophiles. They select and buy their capacitors as if they are rare vintages of wine.

I call them audio-phools.

I use a lot of 0.1u, 12/15/18/22pf. And once in a blue moon, I use 1n or 11n.

Thanks! I will buy those values.

And 1uF is the only ceramic caps I use for general purpose.

For higher voltages and decoupling, use also Electrolytic.

4.7uF also.

Or something like this:

[quote author=Drew Davis link=topic=144080.msg1081997#msg1081997 date=1358796994] Where would you buy from? Spark fun does not have any. [/quote]

Bought from both of these guys. Jameco I have bought their transistor, diode, and 74LS kits. The cheapo chinese dudes, capacitor kits and resistor kits. (Jameco has very fast shipping, typically same day, will get it to you quickly, very reptuable.) (excellent value, low cost barrier, may take 2 weeks to get to you.) (very good value but more expensive for a larger kit, may take 2 weeks to get to you.)

A few other interesting capacitor kits:

I use 10, 22, 47, 100, 220, 470uF electrolytics all the time. For bigger projects (mostly audio amps) I use 2200uF in parallel. I keep in my stash a complete assortment: 0.1, 1, 4.7, 10, 22, 47, 100, 220, 470, 1000, and 2200uF. I keep 25v and 50v varieties up to 1000uF, and 35v and 50v for 1000uF+. Although, due to size and cost, I'll often order the larger ones per-project. Remember, electrolytic caps age, so order in smallish batches and FIFO them.

The only ceramics I ever seem to use are 100nF for decoupling, 20-27pF for crystal load caps, and 470pF for the timing circuit on a particular switching regulator I use. I haven't found a need to have an assortment, although that could just be my usual areas of design interest.

I did order a bunch of mains-rated ceramic caps for power switch arc prevention, but I have yet to use any. I ordered way too many different sizes here. One or two to pick from would've sufficed. They just take up space in my kit now.

I was about to order, but I did not know what tolerance is good: 1% 5% 10% 20% ? What would you recommend?