Very low frequency crystal oscillator

[luben111]

Hi,

I need to find some way to generate 10V to 15V sine wave voltage from 3V battery with minimum current consumption (<100uA), the load is negligible - 1Meg @ 5pf. One very attractive solution is to use the resonance of quartz or ceramic crystals and to get high voltage straight from the crystal.

The problem is that I can't find any crystal or ceramic resonators below 32KHz.

Is it possible to get such low frequency oscillators in miniature package and on reasonable price?

Thank you.

Kind regards,
Luben

 

[FvM]

Reviewing major crystal manufacturer's catalogs, you'll find tuning fork crystals starting from 10 or 20 kHz. Availability from stock may be a problem.

Tuning fork crystals have however limited power capacity and might be unable to handle 10 or 15V without mechanical damage.

 

[chuckey]

Have you tried Google?
Frank

 

[crutschow]

How low in frequency do you want to go?
What frequency accuracy do you need?
How much distortion in the sine wave?

 

[luben111]

Hi,

The frequency is between 8KHz and 20KHz.

Luben

 

[audiomik]

Luben
you might look at having two Crystal oscillators and using the difference signal.
This will at least enable the use of readily available higher crystal frequencies for your project.

Perhaps look at a tuned LC circuit at the output of the summed signal with a suitable secondary to achieve the signal voltage you are seeking

hope this might assist
Mik

 

[chemelec]

Not sure Where or When I got it, but I have a 19.95 Khz Crystal.

So there probably are lower frequency ones also.

 

[luben111]

Hi,

I can't use two different crystals to get the lower beating frequency because it will increase the cost (I'll need some additional components to filter it). But it's a fresh idea - thank you for the suggestion.

Kind regards,
Luben