Cap type for OpAmp integrater circuit?

[RogerTango]

I have this circuit I want to build to experiment with wave shaping, however I am not sure what TYPE of capacitor C1 is.

(Ceramic, Electrolytic, Tantalum, Etc..)

**broken link removed**

Suggestions welcome,
Andrew

 

[Jaguarjoe]

Being such a low value it won't be electrolytic or tantalum. This cap should have high leakage resistance so that its leakage won't affect the feedback circuit. Of course the 1 meg resistor swamps that anyhow. You can use a ceramic cap (cheap) or a polystyrene cap if you want. There are probably others just as good, I'm just telling you what worked for me.

 

[crutschow]

Any ceramic or film type capacitor should work. Don't use an electrolytic or tantalum as they are polarized and have relatively high leakage current.

 

[Brevor]

A film type capacitor, polystyrene or polypropelene would be the best.

 

[bloki]

You must not use polarized capacitor because of possible reverse polarisation. Use ceramic, film or foil capacitor.

 

[RogerTango]

I have that value ceramic cap in stock, I will try that. Thanks so much for the answers, and education. Still learning!!

 

[moffy]

Ceramic caps have high temp coefficient and are not that linear, a polyester, polystyrene or polypropylene would give lower distortion.

 

[crutschow]

Ceramic caps have high temp coefficient and are not that linear, a polyester, polystyrene or polypropylene would give lower distortion.

That's true for critical or sensitive applications. But for the purposes of his homework/lab work, a ceramic cap should work fine. He is unlikely to notice the small temp coefficient or non-linear effects.

 

[moffy]

I agree, but the cap info is useful to know, maybe not now but possibly later. Really shouldn't use ceramic caps in an integrator, it's just wrong.

 

[RogerTango]

Since I am still learning (as a hobby, I am self taught), the additional information on cap types and applications is appreciated.

Thanks!
Andrew