Captret - Capacitor and Electret

[hartiberlin]

I just did a bit of research which caps have the highest negative temperature koeffizient,
so we need probably ceramic caps with the Y5V curve.
These are the best, see enclosed graphics.

These are class 2 ceramic caps, which have a high nonlinear dependance
from temperature...

There are also class 3 ceramic caps, which are even worse
in temperature stability, so better for us, but these are not anymore
produced anymore...unfortunately..

At my local electronic shop they only have the Y5V types in 470 nF maximum,
so this will get a bit expensive , if one wants to build a 1 Farad cap bank....

So yes, the question is, if for instance tantal caps or other caps are
also so extremely nonlinear in temperature , so their capacitance will also
fall so extremely with temperature ?

( This is what we need, falling capacitance with temperature will
rise the voltage on the cap)

Okay, if anybody still finds better caps please post it...

Here is the chart.

Regards, Stefan.

[hartiberlin]

I think my blue 100 nF blocking caps are only the Z5U types,
so the Y5V should be even better !

This is getting interesting now !

Regards, Stefan.

[ibpointless2]

I think my blue 100 nF blocking caps are only the Z5U types,
so the Y5V should be even better !

This is getting interesting now !

Regards, Stefan.

Have a look at these capacitors here, would these work?

http://www.mouser.com/Passive-Components/Capacitors/Ceramic-Capacitors/Ceramic-Disc-Capacitors/_/N-5g90?Keyword=Y5V&FS=True&Ns=Pricing|0

[hartiberlin]

The only one I found at mouser with Y5V is this one:

http://de.mouser.com/ProductDetail/Xicon/140-50V5-224Z-RC/?qs=sGAEpiMZZMt1mVBmZSXTPPQUnq7ol7tGVR0z9O9Sgmg%3d

but it is only 220 nF and too expensive...

[ibpointless2]

The only one I found at mouser with Y5V is this one:

http://de.mouser.com/ProductDetail/Xicon/140-50V5-224Z-RC/?qs=sGAEpiMZZMt1mVBmZSXTPPQUnq7ol7tGVR0z9O9Sgmg%3d

but it is only 220 nF and too expensive...

What about these...

http://www.mouser.com/Passive-Components/Capacitors/Ceramic-Capacitors/Ceramic-Disc-Capacitors/_/N-5g90?P=1z0ynaf&Ns=Pricing|0

I'm using the USA store and i don't know if its different than yours but i see a Y5V 0.01uF 50Volt for only $0.19 for only one. Does voltage have anything to do with it?