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piezo ceramic project


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I placed a small square of heavy felt between the stack and the scale and lost all indications of thrust.  I then placed in thin felt and finally a thin slice of dense foam rubber with similar results. This seems to show that any readings were due to physical vibrations reaching the scale. The attempt to eliminate this issue was with the long lever arm and the thin thread with a small tension onto the scale, and that is apparently insufficient for that purpose, as this latest failure seems to point out that vibrations did follow through to the scale, the thread acting as a conduit of these vibrations instead of a suppressor,  which the scale misread  as weight change. 

the edit button is gone for some reason, and I did want to add that obviously, the felt or foam rubber absorbed the vibrations. 

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thanks for the good input hu??....yes, I have pretty much determined that the thrust measured so far is from the audio standing waves causing a column of air pressure below the stack, as I re oriented

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It seems that if any thrust is developed in the system, it would be very difficult to measure with a scale, as vibrations or other issues would swamp that signal. The plan of sampling the output of each piezo to drive 5 horizontal output tubes which drive a matching stack at much higher voltages is next. I have already begun assembling components to do so. Proof of thrust would be best shown by doing actual work, that is physical movement in a pan balance type setup, which is the tentative plan.   A spinoff of this project is the scan traces which after a year of tests, are still delivering novel and interesting shapes. I wish to capture the traces straight from the input to the scope, as still pictures do not show the details well, and do a screen print onto fabrics such as Tee shirts or other clothing articles. I am not sure if the art aspect of this would be acceptable on the amateur science forum, in the other sciences forum. I do need to find out if a scope signal can be translated directly to a stencil or to photocopier type paper, which I understand is used to do iron-on transfers onto cloth. I have found that simple photos can be copied onto special copy paper for iron-ons, which I plan on doing first, but a direct transfer from signal would be preferred for clarity. If the mods would please rule if I can open another thread here dedicated to that end, or on the other sciences forum, I would appreciate your attention.

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The false thrust through vibrations means that the prior establishment of parameters used are very likely irrelevant to the parameters of a real thrust signal.   A new series of parameter setting scans are being started to see if any stay effects might show up to offer a starting point for the tube driven arrangement.  I have glued a 2mm thick pad of foam rubber onto the end of the stack thinking that will block vibrations more effectively than felt.

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further tests of the suspended stack offer no alternate frequencies of interest, so the usual frequencies of 115, 125 and 161khz are to be used initially in the tube driven arrangement. It does seem that any true thrust, or a "DC" component of the overall signal, is buried within the "AC" inevitable noise of the system, which is what the scale misread as weight change. The question of how to transfer a useful signal from the stack to the tubes without the drive signal, which is of a large P-P voltage, from overwhelming the "echo" of this stimulation that occurs during the delay time, which is accordingly of much lower voltages and is the only signal I want transferred onto the tubes.  I can't simply attach to the stimulation contacts of the primary piezos  to the tube inputs for this reason, so will use the edge contact arrangement I previously used to see what was happening at each active element in early experiments. I will have 5 piezos edge contacting the 5 active ones in the primary stack, and use these to pick up low level signals to be delivered to the tubes without excessive drive signal interference. These five "sensor piezos" outputs will be passed on to the tubes, to amplify this signal to the center five of the new, or secondary stack, with 2 end "buffer" or turnaround piezos added to mirror the primary stack arrangement for a total of 7 piezos. The secondary stack will be mounted on a pan balance arrangement to see if any destabizing of the balance can be achieved with switching the generator on and off. The primary stack will then no longer be attached to a scale, only to be used as signal source. I plan on using 6BG6 horizontal output tubes, used in televisions from the 50s. They have a P-P plate capacity of 6.6KV positive and 1.5kv negative. Since the circuit is low inductance, there should be no excessive "flyback" effect to concern about.

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