using two NPO capacitors in serial for the vas cdom ?

[gaetan8888]

Hello

Is that made any differences in the result by using two NPO capacitors in serial for the vas cdom ?

I don't have the right value of capacitors, so I would use two capacitors in serial to get half of the value of each of them.

Thank

Bye

Gaetan

 

[jcx]

lower V stress is usully good for lower distortion - not that its an issue for many NP0

the extra node allows for 2-pole compensation which greatly attenuates the comp C distortion contribution at audio frequnecies

 

[Mark Tillotson]

Yup, the series capacitor formula works fine for any use of capacitors! The only caveat is when the total voltage exceeds the rating of individual capacitors, then you might require a resistor divider chain to ensure sharing voltage equally (as in a chain of electrolytics in a very high voltage power supply), but here that's not an issue for low-value NP0 ceramics which have negligible leakage and high voltage ratings.

 

[DPH]

Parasitics from an additional cap should be pretty small, but keep them in mind when sizing said caps. (Slash, do convert to a 2-pole comp like JCX suggests)

 

[gaetan8888]

Hello

It's very low-value NP0 caps, two 15 pf in series.

Thank

Bye

Gaetan

 

[ej25awd]

Hello

It's very low-value NP0 caps, two 15 pf in series.

Thank

Bye

Gaetan

Simple answer is yes. You can connect them in series with no adverse effects.

 

[gaetan8888]

Hello

Is there any differences betwen using two 15 pf NP0 in series vs two 7.5 pf NP0 in parallel for a vas cdom ?

Thank

Bye

Gaetan

 

[OlegSh]

The effective capacitance of series connected 15pF capacitors is 7.5pF but parallel connection of two 7.5pF capacitors will give you 15pF effective. So if the actual value is important you have to properly calculate it.

 

[gaetan8888]

The effective capacitance of series connected 15pF capacitors is 7.5pF but parallel connection of two 7.5pF capacitors will give you 15pF effective. So if the actual value is important you have to properly calculate it.

Hello

Oups.. I was mean two 4.5 pf NP0 in parallel.

Thank

Bye

Gaetan

 

[gaetan8888]

Hello

Is there any differences betwen using two 15 pf NP0 in series vs two 7.5 pf NP0 in parallel for a vas cdom ?

Thank

Bye

Gaetan

Hello

It's not two 7.5 pf NP0 in parallel !
It's two 4.5 pf NP0 in parallel.

My mistake, sorry.

Gaetan

 

[OlegSh]

Which capacitance do you actually need? There is always a possibility to series or parallel connect capacitors of different values to arrive closer to the target value.

 

[gaetan8888]

Which capacitance do you actually need? There is always a possibility to series or parallel connect capacitors of different values to arrive closer to the target value.

Hello

I need 8 pf, NPO or silver-mica.

I only have 15 pf and 4.5 pf NPO capacitors.

Silver-mica are best but the shipping for Canada cost more than a full box of capacitors.

Thank

Bye

Gaetan

 

[OlegSh]

Then your options are limited but series connection of two 15pF caps will bring you closer to the target.

 

[gaetan8888]

Hello

Is two NPO capacitors in series will share equally the current and voltage ?

Thank

Bye

Gaetan

 

[OlegSh]

Look up Kirchhoff's law. Equal value capacitors have equal impedance so after you understood the Kirchhoff's law you'll get your answer.

 

[sandrohv]

Hello

Is two NPO capacitors in series will share equally the current and voltage ?

Thank

Bye

Gaetan

Yes, if they are equal value.