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Old Jul 25th 2014, 01:00 PM   #1
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How to set specific vibration frequency within crystal?

I would like to know on how to set specific vibration frequency within crystal, does anyone have any suggestions on what is required and how to do it?
Thanks in advance for any suggestions
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Old Jul 27th 2014, 02:31 PM   #2
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It all depends

My first thought is that your question is too vague.
There are different forms of vibration.
Are you talking about simple mechanical vibration?
or perhaps the vibration of the inter-atomic bonds within the crystal?

Are you wishing to set up a subtle effect?
or shake the crystal to to breaking?
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Old Jul 27th 2014, 03:46 PM   #3
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Referring to following articles, I would like to know on how to set different frequency into crystal based on requirement.

Do you have any suggestions?
Thank you very much for any suggestions :>

"So, motherboard manufacturers will pick a crystal that vibrates at a suitable frequency and then pass that through some electronics to multiply it up to the desired clock speed for the CPU."

http://superuser.com/questions/38015...ate-maintained

Last edited by oem7110; Jul 27th 2014 at 03:55 PM.
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Old Jul 28th 2014, 10:00 AM   #4
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Upping the clock rate on your motherboard is not as simple as just changing the crystal frequency.
Like any performance enhancement, there are a number of side issues to consider.

For example, a higher clock rate will make your CPU run hotter, so you might need to uprate your cooling system.
Some peripharals might not be able to accomodate the increased motherboard speed.
etc.

I am far from an expert on this, but I know that there are people out there who compete to get the maximum possible performance out of thier computers
Upto and including running them in baths of liquid freon to cool them down.

Have a hunt around on the web and see if you can find a forum for PC performance enhancement.

(Be careful about Googleing "Performance Enhancement")
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Old Jul 28th 2014, 05:30 PM   #5
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The main issue is how to set different frequency into crystal based on requirement, if I want a crystal vibrated at 500 hz,
1) Can I able to change the vibrated frequency on any crystal? or
2) Do I need to select specific crystal that vibrate at this specific range?

Do you have any suggestions?
Thank you very much for any suggestions :>
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Old Aug 25th 2014, 06:28 PM   #6
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The frequency of a quartz crystal is determined by its size and shape. It's also possible for the circuitry to use harmonic frequencies of the crystal.

In theory, you could take any crystal and set it to a higher frequency by carefully polishing it down to make it thinner. In practice, just buy a different crystals.
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Old Aug 25th 2014, 06:57 PM   #7
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Originally Posted by SRB View Post
The frequency of a quartz crystal is determined by its size and shape. It's also possible for the circuitry to use harmonic frequencies of the crystal.

In theory, you could take any crystal and set it to a higher frequency by carefully polishing it down to make it thinner. In practice, just buy a different crystals.
I would like to know where to find any reference on quartz crystal's size and shape for different frequency, so I would know what kind of size and shape of quartz crystal to look for.
Furthermore, once I find a crystals, how can I test and confirm the required frequency for their sizes and shapes?

In practice, if I want a set of crystals at different frequency : 500Hz, 600Hz, ... 2000Hz, do I need to collect 16 different crystals at different frequencies?

Referring to your statement about using harmonic frequencies of the crystal, can I simply use one crystal and set its frequency without physical polishing its size and shape? I would like to know what this process is about.

Does anyone have any suggestions?
Thanks, to everyone very much for any suggestions :>
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Last edited by oem7110; Aug 25th 2014 at 07:04 PM.
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Old Aug 26th 2014, 02:16 PM   #8
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Originally Posted by oem7110 View Post
I would like to know where to find any reference on quartz crystal's size and shape for different frequency, so I would know what kind of size and shape of quartz crystal to look for.
Quartz crystals are specified by frequency, not size. The range from 20KHz to over 100MHz. Here is a link that will let you search through about 10,000 different devices.
http://www.digikey.com/product-searc...rystal&stock=1

Originally Posted by oem7110 View Post
Furthermore, once I find a crystals, how can I test and confirm the required frequency for their sizes and shapes?
You would need a measuring device calibrated to a known standard. For example, a frequency counter. But it would be exceedingly rare for a quartz crystal to be out of spec.

Originally Posted by oem7110 View Post
In practice, if I want a set of crystals at different frequency : 500Hz, 600Hz, ... 2000Hz, do I need to collect 16 different crystals at different frequencies?
No. In fact, for such low frequencies, you would use one crystal and generate those frequencies with counters. For example, if you use a 24MHz crystal and 16-bit counter set for 48,000, it will give you pulses at 500Hz. Set the counter to 40,000 and you have 600Hz.
Originally Posted by oem7110 View Post
Referring to your statement about using harmonic frequencies of the crystal, can I simply use one crystal and set its frequency without physical polishing its size and shape? I would like to know what this process is about.
By changing the circuitry around the crystal, you can get some crystals to operate at three time their fundamental frequency. This url will bring up a page describing a series of crystals that one manufacturer offers. Notice about half way down there's a table with columns "Mode of Osc". Most entries are "Fundamental", but two entries are "3rd Overtone".
http://www.ecsxtal.com/store/pdf/HC-49USS.pdf
Here is a url to some crystal oscillator circuits. Notice that circuit 5 to 7 use the 3rd and 5th overtone.
http://www.digikey.com/Web%20Export/...f?redirected=1

Last edited by SRB; Aug 26th 2014 at 02:18 PM.
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Old Jun 20th 2017, 04:33 PM   #9
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I'm not sure if this information satisfies my need to know on all there is to know about quartz crystals?

Would one say that quartz crystals are copy-cats? And that they can be set to any frequencies? I'm not sure if I understand these websites given. Did you end up finding your "any reference(s) on quartz crystal's" ?
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