non-polarized cap insted of polarized one

can i replace the capacitors for non-polarized ones?

SupeR-NovA said:

can i replace the capacitors for non-polarized ones?

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Yes!.

thank you
another question about capacitors... which type is should i use for a crystal at 20Mhz? (the crystal says 18pF but does not specify the type)

SupeR-NovA said:

thank you
another question about capacitors... which type is should i use for a crystal at 20Mhz? (the crystal says 18pF but does not specify the type)

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Ceramic will work. I generally use that.

kinjalgp said:

SupeR-NovA said:

thank you
another question about capacitors... which type is should i use for a crystal at 20Mhz? (the crystal says 18pF but does not specify the type)

Click to expand...

Ceramic will work. I generally use that.

Click to expand...

Yes, I use ceramic as well - basically they are nice and small and easily available. The actual values don't seem very critical, but you should keep them both the same - I've used from 10pF to 33pF (whichever I find first) and never noticed any difference!.

Capacitors

Ceramic will work fine. If you are concerned about frequency stability of the crystal oscillator, you should use NPO. A lot that I have seen and used have a black stripe or bar on them. The NPO means negative, positive=zero. What I am trying to say in so many words is that ceramic capacitors have a temperatur coeficient, that is to say unless they are NPO the capacitance will vary with temperature, and as a result the crystal will vary with temperature. But with the NPO the crystal frequency will remain constant with temperature changes.