How to Choose the Right Capacitor Types

“What capacitor types should I choose?”

This is a question asked by many beginners. I will give you a simple answer to this question without going into all the details. After reading this, my goal is that you should be able to go and find the capacitor you need right away.

Different capacitor types

Polarization

First of all, we boil it down to two capacitor types:

  • Polarized capacitor
  • Non-polarized capacitor

The difference between a polarized capacitor and a non-polarized capacitor is that the polarized capacitor has a positive and a negative side. So it must be placed with the positive pin where the most positive voltage is. You can place the non-polarized capacitor in any way you want.

Do you need a polarized capacitor? Or a non-polarized capacitor? To figure this out, look at your schematic diagram. What capacitor symbol is used?

These are non-polarized capacitors:

Schematic Symbols Capacitor US Style

These are polarized capacitors:

Polarized capacitors

If you need a polarized capacitor, you need something called an “electrolytic” capacitor. There are two types of electrolytic capacitors:

  • Aluminum
  • Tantalum

Aluminum

The most common is aluminum capacitors. It is also the cheapest of the two. Aluminum caps usually come as through-hole components. But you can find some surface mount versions of it as well. Choose aluminum caps unless you have any special requirements.

electrolytic-capacitor

Tantalum

If you need a smaller and more durable capacitor, you should choose the tantalum type.

Tantalum caps are available in small surface mount packages. They can work in a wide temperature range. Note that some tantalum caps come in non-polarized versions also.

Tantalum capacitors

Non-polarized capacitors

If you need a non-polarized capacitor, look for either a ceramic or a film capacitor.

Ceramic caps are small and cheap. It’s the most common choice for non-polarized capacitors. They are often used as decoupling capacitors.

Ceramic capacitors

If you have any special requirements like low tolerance, high reliability, or a capacitor that is able to operate under high temperatures, then choose a film capacitor. It is much better for this.

Film caps can be made of polystyrene, polycarbonate, or teflon. They each have their own properties, but that is out of the scope of this page.

MP3-X2-P1180582b

Other capacitor types

There are a few other types of capacitors as well, but the above ones are the most common. You use other types only if you have any special requirements. For example, if you need a capacitor with very high capacitance, you need a supercapacitor.

More Capacitors Tutorials

30 thoughts on “How to Choose the Right Capacitor Types”

  1. Hi. The topic served to be a fine read although I think it could have been more elaborative , especially, highlighting the voltage range within which each type of the capacitors mentioned herein can be used.

    Reply
  2. Hello, I was wondering if you could help. I have a DJ system and I’m getting a snap/pop through my speakers when I turn on one brand of LED lights “American DJ” but not out of the other brand LED “Chauvet” it also happens when my American DJ haze machine turn on or off. Ive been told if I put Ceramic Disk Capacitors across the hot and neutral that it would go away. If this is true what size of Ceramic Disk Capacitors do I buy? Everything is 120volts AC.

    Reply
    • Hey! Yeah a capacitor will help. But I don’t which size from the top of my head. But you have to make sure it has a high enough voltage rating. BTW – don’t mess with the 120 volts if you don’t know what you are doing.

      Reply
      • Normally its’ a Resister to Diode design however, a clicking sound says a dirty Contact Connection at the Switch to me, or a cold solder joint at the Diode itself.
        An LED normally will not cause this sound on its own.
        – JW USAF Retired

        Reply
  3. I would have liked more information about the different types of capacitor, and what situations they are most suited to. For example, which make the best decoupling caps in digital circuits? Why choose a tantalum in preference to an aluminium? Why choose a polystyrene film instead of a ceramic? What is the different between single layer ceramic and multi-layer ceramic (from a performance point of view). Etc.

    Rowan

    Reply
  4. Hi Oyvind, I have a 35 year old extractor fan in the bathroom which also operates the light on a timer. It has been fine up until recently. Now the lights flicker when the fan is operated. I tried changing the light bulbs for different types without improvement. The manufacturer recommended that I fit a 2mF capacitor. I fitted a 2mF 240 volt non-polarized capacitor across the circuit where it connects to the power source (with trepidation, expecting a bang). There is some improvement, but it’s not perfect. Did I use the right type of capacitor? Did I put the capacitor in the right part of the circuit? Kind regards, Perry

    Reply
    • Hey Perry,

      What type of capacitor did you use? Capacitors of that size (2 millifarad) are usually polarized. Since you are saying yours was non-polarized I’m thinking that it could have been some confusion there?

      Best,
      Oyvind

      Reply
      • Hi Oyvind, Thank you for answering. It is a 2µF 250V Motor Run Capacitor bought from Maplin’s made by LCR. I phoned LCR because I was confused that it had four connectors. I was told by LCR that I was to use one of the connectors from each side of a line at the end of the capacitor and that there was no polarity. Kind regards Perry

        Reply
        • Ah ok. 2µF sounds more likely to be non-polarized.

          Unfortunately I don’t have any experience with capacitors for motors, so I can’t really say if the capacitor is the correct type or not.

          Best,
          Oyvind

          Reply
  5. Hi
    I want to build an amplifier and I’m aware that all or most component have different values I don’t want it to be complicated but I do want it to be portable and have a decent output,
    I’ve seen some you tube designs which don’t explain how the value of the components are relative to one another which would be important to important to make sure they are all compatible.
    Do you think you could help me with this.

    Thanks Ed

    Reply
  6. Hi. I recently took the OEM LED turn signals out of the mirrors on my 2016 F 150 in order to fabricate a pair of dual color emergency LEDS. The warning color (red) is of course fed by my emergency warning system, and works great. The other color is amber which I used to replace the turn signals. The problem I am having is the momentary burst of 12v power the OEM circuit isn’t staying energized long enough to allow the LED to fully cycle at it’s rated intesity. They just flash very quickly. I am thinking of adding a small cap in the line to provide like an extra 500ms to 1 sec of power to allow the LED to completly cycle. Does this sound viable?

    Reply
    • LED’s have different current draws, the Manufacturer Signalling Controller is designed to ultra-low current and “your LED’s are drawing too much current.”
      I take it, it worked just fine with the original ones .. right?
      – JW USAF Retired

      Reply
  7. so that is great if you are working off a schematic – but what if you are trying to prototype something? Then which do you need, a polarized or a non-poloarized? A tiny bit more about why each is chosen would help the article a great deal .

    Reply
    • If you’re not sure, use non-polarized if you can find one. If you need a large capacitor value, you won’t find non-polarized, so then you have to use a polarized one.

      Reply
  8. I need to replace an old capacitor which reads 10M 25V, I cannot find anything online that fits that description. Any help would be greatly appreciated.

    Reply
    • Capital M stands for MEGA, but I highly doubt that you have a 10 Mega-Farad capacitor. That would be extremely high. Could be milli, but micro is more common. Even though that is usually written as 10µF

      Reply
      • Intended to be exact and to prevent confusion like this (esp. In USA where they use mF for both ‘milliFarad’ and ‘microFarad’), the proper prefix for milliFarad (10^-3) should be mF.
        For microFarad (10^-6) it should be the (Greek) prefix “micro”, aka ‘mu’ (which is often not available on smart keyboards) prefix “u” might be used, e.g. 22uF, meaning 22 microFarad, and 22mF meaning 22milliFarad.

        Reply
  9. The difference between a polarized capacitor and a non-polarized capacitor is that the polarized capacitor has a positive and a negative side. So it must be placed with the positive pin where the most positive voltage is. You can place the non-polarized capacitor in any way you want.
    This is right ?

    Reply
  10. If you install an electrolytic capacitor wrong way around it will remove the oxide on the plate that makes it a capacitor and ruin it.

    Reply
  11. i have a 1200w generator and want to use a 1800 grinder what can i use to let it work . can i use a capasitor and what size

    Reply
    • I am not a professionnal but i am studying in the field. As for I know, condenser (capacitor) are use to absorb or boost the tension on a short period of time. You cannot add in a permanent way your missing 600W with a condenser. You need a more powerful generator. Remember that you can’t create energy. The energy in the condenser was just accumulated from the generator.

      I hope it helps,

      Reply

Leave a Comment