Original poster: "Gerry Reynolds" <gerryreynolds@xxxxxxxxxxxxx> Hi Mark,Assuming I'm interpreting what you say correctly, alternating the ends of the caps to get opposite spirals wont have any effect on the inductance. The current doesn't follow the spirals of the wrap. It enters the cap from the side of the spiral (end of the cap). Think of the cap as a long narrow parallel plate capacitor (before rolling it up) where one plate extends out beyond the dialectric on one long side and the other parallel plate does the same on the other long side. Now roll the single plate capacitor up and crunch all the extended plates on one end together and make a connection with an axial lead. Do the same to the other plate and you have the CDE cap. I hope you can see that the current comes in from the side of this long narrow plate cap and exits from the other side.
Gerry R.
Original poster: "Mark Dunn" <mdunn@xxxxxxxxxxxx> My question was about the inductance of the caps themselves. The CDE 942C20P15K have an ESL = 32 nH. A string of (12) is still negligible to my primary inductance(so this question is more theoretical than practical) My question is if I reverse every other cap would I reduce the total string cap inductance. The question goes to the direction that the foil is rolled inside the cap and how the cap is terminated(internally). If the caps are all built identically(as one would expect production product would) and I reverse every other one won't the current flow in the opposite direction around the axis of every other capacitor and reduce the inductance of a string?