Bi-Polar Capacitors (Sound)


The following list of capacitors that are used by sound decoders where a Bi-Polar (Non polar) capacitor is wired in series with the speaker.  The terms "Bi-Polar" and "Non Polar" refer to the fact the capacitor has no DC polarity.  There is no "+" or "-" terminals or markings as such on the capacitor.  You cannot hook it up backwards!

If you look at the picture on the left, the top one is marked "N P" for Non Polarized.





In the Next picture we have some other capacitors with the markings of "B P" for Bi-Polarized.




If you want to learn more about why these capacitors are needed or used, see at the bottom.


The following parts are available at MOUSER: http://www.mouser.com


Parts in bold are the best parts to use in terms of physical size.

 Value
 Voltage
or
Current
Rating
Manufacture
Name
Manufacture
Part Number
 Size
10uF16VPanasonicECE-A1CN100U  5mm x 11mm 
10uF 25VPanasonicECE-A1EN100U5mm x 11mm 
10uF 35VPanasonicECE-A1VN100U5mm x 11mm 
10uF 16VNichiconUVP1C100M5mm x 11mm 
10uF 25VNichiconUVP1E100M5mm x 11mm 
10uF 35VNichiconUVP1V100M5mm x 11mm 
10uF 10VNichiconUSP1A100M5mm x 7mm 
10uF 16VNichiconUSP1C100M6.3mm x 7mm 
10uF25VNichiconUSP1E100M6.3mm x 7mm 
22uF16VPanasonicECE-A1CN220U5mm x 11mm 
22uF 25V PanasonicECE-A1EN220X5mm x 11mm 
22uF 10VNichiconUVP1A220M5mm x 11mm 
22uF16VNichiconUVP1C220M5mm x 11mm 
22uF25VNichiconUVP1E220M5mm x 11mm 
22uF10VNichiconUSP1A220M5mm X 7mm  
22uF16VNichiconUSP1C220M6.3mm X 7mm  
22uF25VNichiconUSP1E220M6.3mm X 7mm  
33uF 16V PanasonicECE-A1CN330U5mm x 11mm  
33uF 10VNichiconUVP1A330M5mm x 11mm  
33uF 16VNichiconUVP1C330M5mm x 11mm  
33uF 10VNichiconUSP1A330M6.3mm X 7mm  
33uF 16VNichiconUSP1C330M6.3mm X 7mm  
47uF10VPanasonicECE-A1AN470U5mm x 11mm 
47uF10VNichiconUVP1A470M5mm x 11mm 
47uF16VNichicon UVP1C470M 6.3mm x 11mm  
47uF10VNichiconUSP1A470M6.3mm X 7mm  
47uF16VNichiconUSP1C470M6.3mm X 7mm  
      
      
      


Why a Bi-polar or Non Polarized capacitor?

Normally capacitors do NOT have any polarization of any kind.  See: Capacitance   However, the common Aluminum Electrolytic (AL) type offers a lot more capacitance per volume at the lowest price than any other capacitor technology.   The consequence of AL capacitor is that it is polarized capacitor due to the physics/chemical properties involved inside the capacitor.  Fortunately most electrical circuit designs use DC power, in which case the polarized nature of a AL capacitor is NOT a disadvantage.  

So what happens if the circuit involves AC power such as found in Audio Circuits.  More specifically when working with speakers? 
It turns out that using those other types of capacitors, (Not AL), will result in a physically large and expensive capacitor. 

Enter the Bi-Polar AL capacitor.  This can be done with the use of a "circuit trick" of placing two polarized AL capacitors in a  "BACK to BACK"  series configuration.  The negative terminals of both capacitors are tied to each other and insulated leaving only the two positive terminals free for circuit connection.   Both capacitors must be EXACTLY the same make and model capacitor.   This is how these Bi-polar AL capacitors are built.  The manufacture simply puts these two capacitors inside one package giving it the appearance of a single capacitor.