# Any Large AT-Cut Quartz Crystals?

Discussion in 'General Electronics Chat' started by Mike M., Oct 12, 2007.

1. ### Mike M. Thread Starter Active Member

Oct 9, 2007
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Does anyone know where I can get a large AT-cut quartz crystal (large enough to resonate around 60 Hz) for use in a 60Hz oscillator circuit that won't cost me an arm and a leg? I just purchased a large flawless laboratory-grown single quartz crystal (100mm) for less than 100 bucks but the original orientation of the crystalline structure before it's round-faceted cut is unknown to me and even if I did know it, I do not have the tools necessary to perform such a cut on my own. If anyone knows of a company that will custom cut laboratory-grown quartz, please let me know. Thanks.

Edit: On a side note, does anyone know the equation that relates the length, and/or area, of a crystal oscillator to its natural resonant frequency? I have searched the internet, probably 20 hours, trying to find an equation that relates the crystal dimensions to its natural resonant frequency and haven't found anything even remotely close. I would GREATLY APPRECIATE any feedback on this!!!!

2. ### cumesoftware Senior Member

Apr 27, 2007
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I think that would be really large. My formula gives 95.6m. You can figure this value by dividing the speed of sound in the material by the frequency. The speed of sound in a quartz crystal is 5740m/s. Thus, a 1MHz crystal would have 5mm.

3. ### Mike M. Thread Starter Active Member

Oct 9, 2007
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Awesome!!! Thank you!!! Now I can figure out the capacitance I will need for a given crystal thickness to produce 60 Hz. Since the thickness of the crystal has to be waaaay thinner than 95.6 meters, I will have to have a large capacitance to overcome the small inductance. So, I will need a large surface area to support the large capacitance current flow and the surface area will also contribute to the overall mass of the crystal, and therefore its inductance, so as to reduce the capacitance size required.

I need a 60Hz oscillator with an extremely high efficiency capable of a few hundred watts of oscillating power to use for an experiment for a magnetic transistor energy amplifier (yes amplifier). I know, it sounds like fiction............but I believe I have found a way to do it based on an oscillator circuit with a copper foil wound core between 2 Ne-Fe-B magnets and a perpendicular hollow cylindrical large-current capacitor. This is based on the geometry of the capacitor's unique magnetic field combined with the efficiency of a crystal-oscillator tank circuit at resonance.

Again.......Thank you very much. I greatly appreciate that missing piece of knowledge.

4. ### John Luciani Active Member

Apr 3, 2007
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Are you sure about that formula? For a quartz watch crystal (32768Hz) you would
get 32768Hz/5740m/s = 175mm. Watch crystals are available in 3x8mm packages.

(* jcl *)

5. ### cumesoftware Senior Member

Apr 27, 2007
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What is a magnetic transistor? Never heard the concept, but I assume that has to do with magnetic fields. Is it the transistor equivalent for a magnetic field (instead of an electric one).

You cannot amplify, or create energy, if that it is all about. You can only convert energy. I assume that you will get energy from somewhere.

I'm not absolutely sure. I assume this formula applies to a transversal sound transmitance through the crystal. But it is really odd a such big value.

6. ### Mike M. Thread Starter Active Member

Oct 9, 2007
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Precisely. The NE-Fe-B magnets produce a continuous powerful field that is analogous to the source-drain field of a transistor. The hollow cylindrical capacitor will act like a gate, given its unique magnetic field orientation, and will stretch and squeeze the Ne-Fe-B magnetic fields in such a way as to induce a large amount of energy into the copper-foil wound core that is contained within the magnetic field paths of both the capacitor and the permanent magnets. If the induced energy on the foil core is just slightly higher that the energy required to maintain the tank circuit, there will be a net positive change in overall energy for the system that is extrapolated directly from the presence of the external permanent magnet field. The 2 mil thickness of the copper foil wil reduce the hysterysis loss to nearly zero and the tank circuit in resonance will reduce the losses sustained by maintaining it a steady voltage.

Edit: I forgot to mention one thing. The voltage induced would be along the plane perpendicular to its physical winding, top to center and bottom to center. The stretching and squeezing from the capacitor will produce a "twisting" effect on the large magnetic field so that during a half cycle at the top it travels CW and at the bottom it travels CCW and the reverse happens for the other half cycle. This will induce voltages gradients that are equal but opposite for both the top and the bottom of the coil. So, the coil must actually be composed of 2 indentically wound coils electrically isolated at the center, like a transformer with a center tap but isolated instead of connected. Then an inverter circuit must be attached to one half and simultaneously combined in series to the other half. If the core remains untapped at the center, the top and bottom connection will see NO POTENTIAL DIFEERENCE. Electrons will just flow back and forth between each end of the coil and the center and produce nothing.

7. ### Mike M. Thread Starter Active Member

Oct 9, 2007
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Are you trying to tell me that an electrical transistor doesn't amplify its gate signal via the external source voltage? If you are not, then why wouldn't a magnetic transistor amplify its magnetic gate signal via the external source magnets?

8. ### thingmaker3 Retired Moderator

May 16, 2005
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"External Source Voltage." The power does not come from the amplifier, the amplifier simply modulates the externally applied power in proportion to the input signal. TANSTAAFL, as Mr Heinlein would say.

9. ### SgtWookie Expert

Jul 17, 2007
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So, 60Hz being the same frequency to the nation's power grid doesn't concern you? How could you conduct any such experiment anywhere in North America without expecting at least SOME kind of influence from that tremendous electromotive force?

If you really need custom crystals cut, you could try Mtron PTI in Orlando.

http://www.mtronpti.com/

They saw crystals 24/7, 365 days a year. But to cut one that large means they would have to dedicate one of their saws to the process, and it takes a good while to cut through quartz.

They know what they're doing, too. Been in the biz for over 40 years.

10. ### Mike M. Thread Starter Active Member

Oct 9, 2007
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That makes sense at first glance but under closer scrutiny, if a permanent magnetic field is distorted continuously then that field will induce a "power" in a coil. With the tank circuit, the "power consumed" by warping that field may be slightly greater that the power induced by that warping. I only say slightly greater because if the hysterisis loss is kept at a minimum and the voltage is high enough, the I^2R losses will be minimal. Even though there is less than unity for this cycle, there are more cycles where more power is generated. If you take the integral of power out of the circuit and divide it by the integral of initial power into the tank circuit, it should be greater than 1.0 due to the multiple reuse of energy that has already been used to produce work.

Like you said before, energy can nether be created nor destroyed, it can only be changed in form. The tank circuit accomplishes just that..........

The creation of a magnetic field in the inductor, the collapse of that field producing a current, the current charging a capacitor to raise its voltage, the use of that voltage to cause a current flow in the inductor, and that current then re-creates a magnetic field in the inductor.

The form of the energy is changing and a certain percentage of it is being used on the next cycle based on its efficiency.

The point I have is this, if that energy were to do something useful in the capacitance phase where it is not subjected to reflected impedence like a transformer, you can get work acomplished multiple times using the transfer of the same energy back and forth from one form to another and it would not violate any law of physics. It just violates intuition based on the current paradigm of physics.

11. ### Mike M. Thread Starter Active Member

Oct 9, 2007
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Thanks for the link. I don't think any influence would be significant beyond the point of negligible. I want it to be 60 Hz so that it is compatible with the North America Standard and may be placed in parallel on a house or an apartment. If every person in the United States had a unit subsidized by the U.S. government that put out 1 KW and was connected to the grid at the location of every residence, We would probably be about 3/4 as depedent on foreign oil. It wouldn't eliminate the problem but it sure would buy us some time and relieve some economic pressure. All it takes is people continuing to think about the universe in a non-traditional way and it is inevitable that the human race will find an energy loophole in the laws of physics where we don't have to violate them in order to accomplish our goal of bypassing them. I would personally prefer it sooner than later, despite the major global consequences that it will pose in the beginning (first hundred years or so).

12. ### cumesoftware Senior Member

Apr 27, 2007
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Basically, what you said is that you want to amplify, therefore create energy. A transistor amplifies a signal, but doesn't create energy or amplifies energy. It rather uses readily available energy.

What the transistor does is to control the current from the emitter to the colector by the means of the current biasing the base. The energy is already present. A transistor only controls it. Basically, this means that the energy that the transistor outputs comes from the emitter, which by its turn comes from the power supply. So, basically you are modulating the energy coming from the power supply, not creating energy.

Your magnetic transistor should do the same, but using a magnetic field.

You cannot bend the laws of thermodynamics. Don't expect to create energy at the cost of nothing. I have a theory that even the tidal energy is not that free and renewable, since the sea mass and the moon influenciate each other mutually (action-reaction physics). When you are using tidal energy, you are creating local water masses that won't move so freely with the moon, slowing it down by a tiny fraction.

Also, by mistake, I gave you the formula for the wavelenth of a sound wave. I have to look for the formula applied to a body.

13. ### Mike M. Thread Starter Active Member

Oct 9, 2007
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Not exactly. I just want to use the fluctuating magnetic field of the capacitor to distort the permanent field. The permanent field will be there as long as electrons exist in the Nd-Fe-B material. That source of energy is limitless and relatively dense. I want to "modulate", as many have put it, the permanent field within the capacitance-only framework so that any work done to the permanent field will not be reflected back as an impedence, as is what occurs in a transformer.

That all rests on the presumption that impedence is not reflected in a capacitor but only an inductor-inductor relationship. Since I have never seen anything in my life that suggests that it is, I would like to pursue the project. If I do find information to the contrary, whether it be an outside source or by experiment, I will consider it a learning experience and move on. If impedence isn't reflected back through capacitors, it may have great implications for renewable energy. If you have ever played around with 2 N50 rating Ne-Fe-B magnets, you know how much energy is constantly pouring out of them and is untapped. I had 2 small ones and they tore the flesh off part of my arm because I was completely unprepared for the level of energy I encountered.

14. ### cumesoftware Senior Member

Apr 27, 2007
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Being that the case...

15. ### Mike M. Thread Starter Active Member

Oct 9, 2007
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I just thought of a simple way to test and see if capacitance is subjected to reflected inpedence........

If you take some insulated wire and make a long but small diameter coil around, say a 1/8" iron rod, and then take the resultant coil and wrap it into a pancake coil you will emulate a capacitor's magnetic field geometry. This dual-coiled pancake coil can then be placed in a petri-style dish containing a melted dielectric, such as a plastic, and then allowed to cool. If this thin hockey puck shaped clump of dielectric containing that dual-coiled pancake coil then has a metal plate placed on each side of it, if there is any reflected impedence then the plates will register an AC voltage when an AC current is passed through the center coil contained within the dielectric.

If a capacitor IS subjected to reflected impedence, the device described above can be used as a single-coil transformer without the need for a second coil or a complex core.

This actually is starting to look like a win-win situation because no matter what the truth is about reflected impedence in a capacitor, a new type of device will be available.

16. ### thingmaker3 Retired Moderator

May 16, 2005
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Or just use a potting epoxy. Or RTV Silicon. (See, I really am trying to be patient and open-minded.)

17. ### Mike M. Thread Starter Active Member

Oct 9, 2007
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Thermodynamics I took thousands of hours of classroom study on that subject but it never seemed convincing. It almost gives me the feeling that astrology as a science does. Don't get me wrong, It is extremely useful and is mathematically sound at the human level but I think on the quantum level and it all goes to pieces there. It just "feels" like it is an incomplete theory, especially when it comes to random quantum events that can be forced into coherence.

18. ### Mike M. Thread Starter Active Member

Oct 9, 2007
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That actually sounds a lot less messy than what I had planned. Thanks. Manually wrapping such a small and long coil is turning out to be a big pain in the fingers! 3 inches down and about 15 to go. I ended up using 1/8th inch diameter solder wire so I can bend the final coil into a pancake coil without having to use tools that could potentially scrape off the insulation film.

19. ### Mike M. Thread Starter Active Member

Oct 9, 2007
104
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Here is a drawing of the properties of a pancake coil made from an existing coil. The properties are almost identical to a capacitor's electric flow and it's generated magnetic field. Sorry, I'm not an artist.

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20. ### Mike M. Thread Starter Active Member

Oct 9, 2007
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Attached is a picture of the coil before encasing in a capacitive substance. I would greatly appreciate any final advise on what type of material I should use because this thing really was a absolute pain to make by hand. Right now silicone looks like the easiest but is it a good enough dielectric for a capacitor? Thanks. Oh, and I found the actual velocity of sound in an AT-cut quartz crystal.......

For an AT-cut crystal ρq=3340 m/s and vq=2650 Kg/m3.

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