– The primary rating of a capacitor is “Capacitance,” as measured in Farads, (pF, nF, uF). While this is the only number necessary to define an ideal cap, real world capacitors have limitations that require additional numbers to quantify. Thus, there are other “specs” which define the ways in which a particular capacitor deviates from the ideal.

– “Operating Voltage” is a common and important specification. While the ideal cap works at all voltages, real caps have limits.

– Equivalent Series Resistance, leakage, inductance and signal dependent factors may need to be considered in certain applications.

– Parallel capacitors add their values. 50uF in parallel with 50uF gives 100uF. In this case, the effective voltage rating of the pair is set only by the lower-rated unit. If the two parallel caps have the same rating, simple: the pair also has this rating.

– Using capacitors in series reduces the capacitance to below that of either individual unit. C(total)= C1xC2/(C1+C2). In this case, the working voltage goes up, but in a complex way. If the two series caps are identical, then their working voltage doubles compared to each individual cap. If they are not identical, it gets complicated, and depends on the exact values and the working frequencies. In any event, the working voltage of two series caps is greater than the lower of the pair.

– Capacitors can be made out of many materials, in constructed in many ways. Each has advantages, and the selection of caps for a particular circuit application is one of the basic skills an engineer is taught.

OK, now we can jump into more detail on the technical aspects of capacitor performance.

Capacitance.

voltage

esr, etc.

polarity

non-linearity

modulation

measuring caps

use in circuits: blocking, filtering, bypass, phase shift, etc. In the audio path or not? Used in impedance range or not?

audibility

manufacturing

current thinking

research

“re-capping”

conclusion

## Comments

You

Need

To

Finish

This

!

I need more! But seriously, thanks for posting what you have so far, very interesting. I never thought capacitors would be one of those things everyone disagrees on, including how to test. I hope you have time to finish this.