Capacitors! Most useful values? pF/puffs are good for what?

Thread Starter

Hamlet

Joined Jun 10, 2015
257
I was looking over my collection, making an order to fill the depleted values (100nF, 10nF, 0.47uf etc.)

What values do you guys and gals use the most?

Why do I have 43 different values of ceramic disc below 1nF? I rarely seem to use those puffs, what & where are those values used?
 

MrChips

Joined Oct 2, 2009
19,768
Same question can be said for resistors.
Where and how often does one use a 1Ω or 22MΩ resistor?

The answer is - it depends on your field of study and application.
For example, you will need 6pF to 22pF capacitors and 22MΩ resistors if you were building a crystal oscillator circuit.
 

MaxHeadRoom

Joined Jul 18, 2013
19,461
As per MrChips, it all depends on the application, as a very general rule, the higher the frequency used by the application, smaller values are seen.
RF decoupling etc.
Max.
 

crutschow

Joined Mar 14, 2008
23,803
Look at the schematics for the typical circuits you are interested in and you will see what values of resistors and capacitors are commonly used.
 

MrChips

Joined Oct 2, 2009
19,768
Let us look at some broad applications. What type of circuits are you most likely to be building?
  • Audio amplifiers
  • Audio tone controls
  • FX stomp boxes
  • Linear power supplies
  • Switch mode power supplies
  • 4000 or 7400 series digital circuits
  • Microcontrollers
  • Arduino or raspberryPi boards
  • RF or HAM radio circuits
 

wayneh

Joined Sep 9, 2010
16,128
Anytime I buy a capacitor, I usually by several. They're cheap and I might want to duplicate whatever it is I'm building. The only capacitor value I've bought in bulk to have a pile on hand is the 0.1µF ceramic caps for decoupling. I go through those like candy.
 

MrChips

Joined Oct 2, 2009
19,768
4000 and 7400 series digital circuits
You will need lots of 0.1μF disc capacitors
Some 10-100μF electrolytics
Occasionally, some 100pF to 1μF for timing circuits

Linear power supplies
1-10μF ceramics
100-4700μF bulk electrolytics.

SMPS
Same as above, according to datasheet recommendations
 

MrChips

Joined Oct 2, 2009
19,768
There are many different types of materials and construction techniques used in the process of manufacturing capacitors.

There is no one better than the other. They all have different properties and characteristics such as stability, reliability, temperature dependency, ESR, leakage, aging, voltage breakdown, and of course cost.

@bertus has already posted in post #7 some helpful documents on choosing capacitors.
 

Thread Starter

Hamlet

Joined Jun 10, 2015
257
Reading, reading, readin...

QUESTION:
Capacitor voltage rating... Apart from larger size,
is there any disadvantage to using a 250v electrolytic
in a 12v circuit?
 

Thread Starter

Hamlet

Joined Jun 10, 2015
257
Never-mind, found my answer in the PDF. For those who want to know,
electrolytics are closer to their value at intended voltages. (I don't see
how that's possible.) Also something about the oxide being maintained
at lower voltages than rated is problematic somehow.
 

Thread Starter

Hamlet

Joined Jun 10, 2015
257
I just tested a dozen 10uf electrolytics from 16v all the way to 250v, and could NOT
discern any meaningful difference in capacity. Admittedly, my LCR meter is a cheap
one.
 
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