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Author Topic: Variable Resonator Crystal  (Read 2192 times)

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Offline airman00Topic starter

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Variable Resonator Crystal
« on: May 11, 2008, 10:56:04 AM »
Anybody know if a variable resonator exists? and where I can buy it from?


EDIT: not like a radio which takes power to receive . I want to harness the piezoelectric effect from a variable source - basically get electricity from a variable resonance crystal  , or maybe a different medium

thanks,
eric
« Last Edit: May 11, 2008, 11:37:37 AM by airman00 »
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Offline izua

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Re: Variable Resonator Crystal
« Reply #1 on: May 11, 2008, 12:20:44 PM »
check out TXCO - temperature controlled crystal oscillator.
variating the core temparuture variates the main frequency
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Offline airman00Topic starter

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Re: Variable Resonator Crystal
« Reply #2 on: May 11, 2008, 01:03:48 PM »
hmmm


im looking for something that is variable crystal without putting in energy , like mechanical turning or something 
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Offline 555 timer chip guy

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Re: Variable Resonator Crystal
« Reply #3 on: May 12, 2008, 01:17:01 PM »
you could put a variable capacitor in series with a the cristal it dos change the frequency to some extent but the best way to go is just use a 555 or if you need higher frequencies like 100KHz and up you could use a tank circuit witch is just a capacitor and an inductor in parallel you can change the frequency by changing the values of the inductor or capacitor.

Offline airman00Topic starter

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Re: Variable Resonator Crystal
« Reply #4 on: May 12, 2008, 01:34:47 PM »
I'm looking for a receiver for signals <30 hz

does that exist? thats why I want to be able to variably tune it

would the crystal and variable capacitor work?
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Offline Steel_monkey

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Re: Variable Resonator Crystal
« Reply #5 on: May 13, 2008, 03:13:06 PM »
30 Hz is too low. Why not just take MCU and generate required frequency with high resolution and accuracy?

Offline 555 timer chip guy

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Re: Variable Resonator Crystal
« Reply #6 on: May 13, 2008, 06:07:03 PM »
generally you should use at least 100kHz or more for RF. what are you using it for? I have many receiver schematics laying around if you like I can post one.
« Last Edit: May 13, 2008, 06:08:02 PM by 555 timer chip guy »

 


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