I have got one of those small crystals, packed in a silver package, low-profile, two pins. How do I connect it so that I get the output that is printed on it (7,680)?

Cheers!
Lac.

 

It sounds like you are looking for an AC output at the crystal frequency so the crystal is only part of an oscillator. Crystals can also be used in filters.

__________________
stevez

 

soo..? who do I get the desired frquency from the crystal?

 

The simply method to build it with CMOS inverters.

Attached Images

xtalosc_202.gif (2.3 KB, 508 views)

 

w00t!? Don't they need power or anything? Just the crystal, a resistor and an inverter gate, and then I get my square 7,68Khz output?? That looks way too simple and mystic!

Cheers!
Lac.

 

What would they need power for? THink of it.. it is just a piece of.. well crystal. There are no active circuits involved inside the crystal. The output power avalilable from the oscillator (not xtal) is from the inverters that sebi has shown.

A crystal by itself is a passive device of sorts. It only reacts to a stimulation input.

 

Indeed. Woot. Not a phrase often associated with electronics, but maybe I'm just getting old...

:lol:

 

The inverter obviously needs power, it's normal not to show power lines to chips in logic circuits.

Also the crystal is more likely to be 7.68MHz, rather than KHz.

__________________
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Hm.. I can't get the crystal to generate any frequency at all. I used the first scematic posted over.

Cheers!
Lac.

 

Anyone know why I'm not getting any output? Does the resistor have to be 10M? Thats pretty high.

Cheers!
Lac.

 

Try this circuit, if you dont have 74HC14 you can use any inverting HC gate...

Attached Images

crystal_106.jpg (19.3 KB, 405 views)

 

Does the caps need to be 22pf? Can't I use something bigger, like 1uf?

Cheers!
Lac.

 

No.The cap. value depend from quartz freq. With 1uF cannot work.

 

You can use something similar 10pf-50pf

 

But doesn't the caps depend on the crystal frequency? I wasn't able to find any datasheets.

Cheers!
Lac.