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Everything posted by hoola

  1. the basic difference between mine and woodwards' idea, is that they sitimulate all piezos concurrently, and shut them off, and see a result. Mine are lined up in a stack and stimulated separately and run continuously. I offered the "phononic gain" idea fairly early in the going, so let me reiterate it now. There are 5 active elements, two passive. The overall action is like a rail gun, that is, the shock wave is generated in the first which is placed at the top of a vertically arranged stack. This shock passed to the next one down, wherein I stimulate that next one,,,,,at just the right time....and so on down the line, as in the rail gun analogy where each magnetic kick raises the velocity of the projectile more. The shock wave scope traces showed this early on with steep vertical up deflections at the end of scope traces. Another main diffference is the way the piezos are held. They clamp them down in an apparently vise like manner, excepting the rubber material, whereas I torque my stack lightly, on a central nylon rod, as when the individual piezos expand axially, they contract radially. With an overly restricted mounting, the shock waves diminish due to this radial restriction. The elements must have some physical freedom to move within a certain range. This indication was shown on the scope traces, and also the sound of the singing decreases either tighter of looser of a certain torque, in an obvious sweet spot of shock transfer and phononic gain. The nylon rod I use allows an even torque pressure within the ring elements (SMR3515T55 from steminc) of the stack, and is simple mechanically. I now use 1/2" rods, but have some 1/4" ones on order to try a more pliable rod, but with a somewhat higher torque to see how that responds. Hopefully, that will broaden the "sweet spot" and lower instantaneous stress on the elements. Today I am working on the series string transistor idea using 4 seven hundred volt transistors (NTE165) to see if I can eliminate the tubes. The used tubes I bought first are failing, perhaps in part due to cathode stripping from the excessive DC plate voltages needed. The can take a large pulse, but not designed for much more than 800 volts continuous. There is an occasional heavy arc across the stack which needs eliminating, as transistors are less forgiving of such insults than tubes. I hope the .027 caps on order will show a good transfer of energy, if not they can be easily paralleled to the needed value. I hooked the stack directly to the tube plates to maximize transfer of pulse, and was curious to see how much voltage can be safely placed across the elements. This appears to be 3KV. The AC pulse signal is likely only 50% of the supply running as a class A amplifier with that inherent limitation. The piezos are a high impedance, low inductive load, so no "flyback" raising of the voltages. The tubes were designed with running into a 15K tuned load, in early television and could induce upwards to 30KV to accelerate the electron beam to the screen. With a supply voltage of 6-7KV being blocked by the caps, I hope to get a 3KV AC signal pulse to the stack, as a pracitical maximum for now.
  2. I have ordered a 5kv, 30 ma electronic neon transformer that is listed as dimmable. The case may be able to be opened to see if I can bypass the reg circuit if it doesn't work any better than the old one, which is also listed at 30ma max, but with a voltage listing of 10 kv. Hopefully the new one will regulate better at the 3kv level using the dimmer control. I have also ordered five .027@4kv caps to block the DC from the HV supply getting to the piezo inputs, perhaps solving the voltage issue if the caps can pass the signal from the tubes to the stack without excessive loss.
  3. the re-wire of the neon transformer did not go as hoped. The conversion to full wave bridge and not using the center tap has made the output more uneven than before. I will have to return the supply to it's previous config. until I can find a standard wire transformer. The online description of the various current regulation methods used in older neons is not well explained, but acts as a sort of autotransformer, which I think uses a saturable core., but that is primarily to level an unsteady AC input voltage to equipment, not limit current. Circuits referred to as "shunts" surround the windings and act as the current limiter.
  4. I found that the driver transistors in the interface unit were being overdriven. I had adjusted them almost full gain before I took out the horizontal ouput transistors, and I thought the transistors were loading down the feed lines, but I think the diode action was distorting the signal, and not merely loading them down in a linear fashion. When checking the interface module again, output transistor gone from their sockets, and with the piezos turned on one at a time, the sound coming from each one was louder and more complex, even prettier, as the interface gains were turned almost off, down to about 10% full rotation. This correction is coupled with a small output gain, which probably would be higher, but the corrected interface gain settings cause the tubes to draw more current, which loads down the HV more, and thus limits output gain.
  5. ,the new structure is working out well with weight changes in the 4-8 milligram range. The scale is positioned on the right side of the arm now, was previously on the left, with the 10" thread tied to the stack bottom, suspending a weight, which sits on the 3/8" felt pad, itself placed upon the scale. The scale now reads lower instead of higher, as the arm wants to torque in a counterclockwise direction just as before. Tomorrow I will re-wire the HV supply to remove the voltage sag under load and make the process less dramatic when the volts swing up and causes stack arcing when not being driven.
  6. I have found that though the individual piezos have a 44 khz resonance, that has little to do with the overall picture. The stack is scanned at a frequency somewhat higher, normally from 100k up to 200k, and I stay away from resonance, avoiding potentially over stressing the piezos. The thrust output seems no better at resonance anyway, and an additional bonus is that the stack runs almost silent at the higher frequencies, which is easier on the ears and seems to rule out simple acoustic waves bouncing off the table or into the ambient air and skewing results. I have a neighbor dog that comes by and she doesn't seem to hear any "dog whistling" coming from the shop, so ultrasonics seem unlikely. Just as a speaker has a resonant frequency, you don't necessarily need, or want to peak that out with the crossover, sometimes you want to suppress that frequency a little (or tune the cabinet below it to give a linear output regardless of input freq. I know that the Woodward team sweeps through resonance, which may be the way to go with their parallel, pulsed inputs, but that I have found doesn't apply here...the stack can sit there quietly putting out 150 micronewtons all day without any observed problems. The voltage issue is not overly critical right now, getting the new support structure finished it the next goal.
  7. I am wondering if multiple ECG165 bipolar horizontal output transistors could be series strung to give "tube like" voltage swings at the collector of top end of the series, with the bottom end transistor emitter at ground, while parellel driving them using caps to keep each base input DC isolated and allow for individual biasing, thus keeping each transistor running at it's normal rating? I read that the basic construction design of power FETs is with series/paralleling many small FETs to give additive power and voltage in one case package. Couldn't that be done on a larger scale with metal bipolars?
  8. a simpler way of dealing with stack arcing is to make the ground return lines at HV potential, that is, the DC level of the high voltage (instead of 0 volts), filtered and direct from the power supply, and the signal input lines at that same potential modified by the sine wave signal, which will be less voltage on average due to tube conduction. That should reduce the stack voltage differentials sufficient to exceed the 3KV level I am stuck at now with a quick and easy mod. I had considered using input line caps as DC blockers, but caps with a large enough capacity / voltage rating were not chosen due to expense and practical concerns, so I went with the present scheme. I put DC blockers in the drive unit, as the HV that fed the output transistors was only 600v and easy to do with cheap, off the shelf caps. I will begin building a new compact drive unit that contains the square wave oscillator, the 4017 IC decade stimulator, the interface circuitry (basically just 5 gain stages from the 4017) and all relevant controls within one small prototype box. That leaves the HV supply and the tubes as the bulky components, which could be downsized considerably, with a switching type HV supply (much easier to filter) and perhaps high voltage transistors capable of kilovolt operation. The horizontal output transistors (since removed) in the main driver unit were the highest voltage transistors I could find online, and I still cannot find anything that can sub for tubes as of yet. Perhaps transistors cannot be made to handle much more that 1KV due to their physical structure requirements. I think radio and tv stations still rely on tubes for their final.
  9. an increased operating voltage beyond 3 KV will require some adaptation of the stacks. The entire stack assy. could be dipped into some sort of sealant that might prevent breakdown on the outside, but that leaves the insides with the need to seal them too. If the central post were smaller diameter, perhaps of 3/8" instead of the 1/2" nylon bolts currently used, the bolt could be held in alignment to true center, then sealant could be pumped in to fill the interior cylindrical gap, insulating the interior rim of the stack. In this way the entire stack might be usable up to the 10 KV potential I am capable of. The sealant would have to be flexible enough to not interfere with the torquing process, perhaps common clear silicone could be tried first. The stack might be torqued up to peak as the sealant is curing, preventing problems that could arise by torquing the stack if the sealant is fully cured and less compressible. An alternative method of sealing the stack might be to fill the interior completely with sealant, and not using the central post, but adopting the Woodward team method of clamping the stack with end plates, with torque bolts positioned around the exterior. This would perhaps simplify matters quite a bit by simply torquing the stack to a predetermined amount, then dipping the whole thing at once. Another mod might be not to use a common ground on the stack. The input lines of course are all separate, but I have tied the grounds together to simplify matters. If the grounds were separated also, the inputs could be switched to what were ground connections, and vice versa. This might make the stack respond with a negative thrust instead of positive thrust, as inverting the firing order has not done that, as I expected it to.
  10. the first line of the previous post should have read...removal of output transistors...as they are all out. Today I will break down the level arm assy. to bring the balance to neutral, as the pivot point is below the arm and will fall to one side or the other if placed in the center. In this manner I will be able to place calibrated weights on the arm and test without fear of scale interactions, and get more precise estimations. The scale will be temporarily placed back on occasion to peak out bias adjustments and other criteria.
  11. removal of the output transistor has increased the drive to the interface module to bring back the 30/2=15=150 micronewton expectation. From now on I will designate just the micronewton calculations as I feel 99% confident that there is a valid force being developed. The 200K drive frequency is near silent, with only the hum of the HV transformer as the predominate sound. I tried hooking up an ammeter in the ground return of the HV supply and oddly got no reading., perhaps due to some interaction with the internal current limiter. I am sure that issue is not important, but the sag on the HV will be an issue when the new tubes come in and the current requirements go up. The built in current limiter in the neon transformer seems to be in the center return line, so next I will rewire the supply for single end and remove use of the center tap. This will allow a maximum output of 10KV, but the practical max has been around 3KV. The humidity is down today and there was little stack sizzle and no arcing at 3.5 KV. I will research what other octal base transmitter tubes with higher power could be substituted in without much circuit rewire. At this point the 4017 IC driving the interface module, driving the arm stacks are the only active elements. The scopes are currently not hooked up, as they were sampling the edge contact assy. The end piezos on both stacks have not been hooked up yet, only used for the "turnaround" function, but now I will transfer the 4 scope lines over to the end piezos on the stack arms. The end stack sensors gave a much more interesting visual display, almost a character generator function, that was not present with the edge contact pics.
  12. today I disconnected the driver stack/edge contact assy. from the interface module and ran a new set of leads from the bases of the output transistors and fed those directly into the interface module and got weak weight changes of less than 5-6 milligrams. The signal at the transistors bases was insufficient to drive the arm stacks properly, even with adjusting the interface gain controls to max which is puzzling as I thought i had plenty of headroom to compensate for the differential. Next I will simply remove the output transistors which will remove the signal drain from the base currents which will give an increase. I am trying to simplify the apparatus, and if I eliminate the drive stack/interface piezos, that will be a 50% reduction in number of stacks, plus no need for output transistors and their attendant 600V power supply. This will be important for station keeping, as I presume there will be 3 separate thrusters, one on each axis
  13. this evening I hooked the sweep generator back up to drive the mechanism and found no useful increase in output, but the sweeping sound does mimic the "flying saucer" warble noise used in science fiction movies from the 50's, but that generator is difficult to use and the main generator was quickly subbed back in.
  14. today I replaced the delay and delay fine tuning controls with a single 50K ten turn contol. I set the arm back onto the scale and read the what is now the expected max of 30mg/2=15mg= 150 micronewtons at various parameter settings. The 200K frequency is now my favorite as it is nearly silent, which reduces the possibility of acoustics from the stack causing misleading readings, unless there are ultrasonics that could cause an issue. Since I have two stacks at right angles, if acoustic waves are coming out, they might cancel out, lowering the possibility that there is an issue there.
  15. a number of multi wire miniature slip ring assemblies are available, but set up for lower voltage 50-60 hz.AC use. The issue of internal arcing may be gotten around by using two slip rings, one to carry the five drives and a second to carry the ground return. The friction coefficient is not a listed parameter, but will order them for testing.
  16. I had been having trouble with the unregulated HV supply going over 3 kv and getting some minor stack arcing when not driving them and found that increasing the forward bias of the output tubes gives a good enough regulation to keep the HV down to 2.5 kv maximum, and providing about 2 kv when drawing tube current. With this adjustment the tube power outputs are increased and today I got the arm to bounce 1/4" and can easily levitate half that. If the stack arm was perfectly balanced and was on a low friction central bearing with a very low friction commutator or rotary tranformer system it might make complete revolutions and effect rotary motion. I wonder if the ultimate speed of that rotation would be held to seventeen times the speed of sound in air ( the supposed speed of the shock waves moving through the stacks) or if it relies on a more fundamental interactions and could turn faster. I would suppose this thing would move in space, so what would constrain it's maximum theoretical speed in a vacuum? The tubes are used and check only fair, so soon I will get 5 new ones and see if the power increase would be as advantageous as today's bias adjusment was.
  17. yesterday I had written that I had achieved movement of the arm a visible amount, perhaps 1/8" at a maximum and described certain details. The posting disappeared, as they sometimes do and I didn't re type it, but went on and did the low freq. test and so let me describe it now. I removed the scale and balanced the arm until it almost floated off the table top where the right side rested. Upon scanning through the known hot spots, at around 125khz I detected what I thought was a slight lift off of that side. I had noticed that the arm has an overall resonant frequency of about 1 hz when manually perturbing it, and so I pulsed the generatior in 1 second intervals with a brief off between cycles. The stack began to lift and fall at this 1 hz rate to my astonishment. After some time and calling in my neighbor to witness this, I managed to lift the arm up at the 1/8" height continuously. I observed these events and took videos of both the initial bounce and the continuous displacement of the arm. I was so gobsmacked with this that I had some trouble believing what I saw and had some difficulties in concentration when first blogging these facts, and when the entry disappeared simply went on with the low freq tests and tried not to over react to the headache that was increasing in intensity as I tried to focus on something else.
  18. I have re - introduced the scale and adjusted the main generator up to 2mhz, and have achieved similar forces of 10 milligrams or so. I do this to see what is the highest drive frequency that is effective for generation of thrust and it seems that the 2mhz setting is near or at the top of the useful frequency band. The advantage to using this higher frequency is that the entire apparatus in now silent, and the hum of the HV power transformer loading down by tube conduction is the most obvious way to determine stack stimulation. Next will be to determine the lowest generator setting to give thrust readings. I don't know why the last post was doubled, it was not deliberately done by me, anyway I have found multiple peak and valley of thrust points as you go down the dial until I got down to 60hz or so. I didn't change gen range and do a more precise measure, because the noise it produces at lower frequencies is so loud the piezos may become overstressed and I quickly ended that test. I have found 2 small circular chucks missing from a piezo some time ago, I think may have been caused by a test wherein I removed the "turnaround" element on one end. I quickly shut down the driver when a noise came out of it that seemed damaging. I am not sure that was the cause, as I disassemble each stack on occasion to inspect for damage, and the disassembly after that incident was when the damage was first seen. The hum from the neon HV tranformer has turned into an indicator of thrust peaks. This new finding is pretty exciting as the current drain to the tubes could be largely dependent upon overall stack impedance. As they "talk to each other" and form certain relationships, like a self syncronizing set of pendulums, the overall impedance goes down and thrust goes up. This seems a reliable behavior, but just noticed tonight and I expect exceptions. I am curious as to why I have not found any settings that produce negative thrust, as I had seen before. I had found that the neg. thrust peaked at about 1/3 the level of the max. positive thrust. Other curiosities include that once you perturb the particular sweet spot of seeming harmony, it is not always easy to re establish it. I have also long observed that the relationship that develops when scanning down in drive frequency to a sweet spot is hard and sometimes impossible to re establish coming up on the drive frequency as you approach the sweet spot freq. I will install an ammeter into the HV supply and use that when the noise background too loud to hear the hum and maybe find current peaks that aren't apparent with hum level. At the end of tonight's test, I didn't have to look at the scopes, just listened for the transformer hum. I have been getting a reliable 15 milligrams in many parameter settings, but the 125khz setting continues to be the main frequency used.
  19. I have re - introduced the scale and adjusted the main generator up to 2mhz, and have achieved similar forces of 10 milligrams or so. I do this to see what is the highest drive frequency that is effective for generation of thrust and it seems that the 2mhz setting is near or at the top of the useful frequency band. The advantage to using this higher frequency is that the entire apparatus in now silent, and the hum of the HV power transformer loading down by tube conduction is the most obvious way to determine stack stimulation. Next will be to determine the lowest generator setting to give thrust readings.
  20. I set the HV to 2.5KV , removed the scale and balanced the arm to where it was barely offset to the right side and noticed that the gap between the bottom of the right stack and the wedge I inserted under it was slightly affected when activating the stacks, seeming to raise it up just to the level of barely perceiving a change in the gap, perhaps 1/32" I then turned the main generator on and off, syncing up with the gap appearing to separate from the wedge, and upon doing so, it became obvious that the gap was increasing with each pulse of signal from the generator of about one second in duration, to the point of raising the gap bounce to nearly 1/8", and clearly visible. This is hopefully is from actual impulse thrust, and not acoustic thrust from interactions with ambient air. A further test with a reduced air pressure, helium, or true vacuum may be needed. Hopefully further improvements will make the lift thrust so obvious that those tests may not be needed.
  21. after further fine adjustment of position of the actuator arm, I placed a 2.6 gram weight on the left stack end and read 5.2 grams on the read scale, giving a doubling of actual scale readings, hence the 50% reduction in all measures. I placed a 3/8" thick piece of felt between the actuator arm and the scale and with 1KV tube supply got 9-10 milligrams increase, and upon increasing to 2KV got 20-21 milligrams increase, a near linear doubling. If the reading indicates a predominate proportion of thrust, the felt being an effective block to vibration, the true thrust is 10 milligrams at 2KV. This is approaching the level of removing the scale, and potentially seeing arm movement. The stack seems more sensitive to high voltages today, hearing some sizzling and frying at 2.5 KV as the humidity is up this morning. The interface module that takes the output from the edge contact assy. has individual adjustments for each output. They are all set at midpoint so as not to overdrive the tube grids, and they can each be switched on or off by the main chassis, but I have not yet tried a reduction of inputs with these controls, varying the relative ratios of them, offering a more fine tuned approach to the control of the impulse peaks and valleys within the stacks.
  22. today I came by some vintage surplus interior 5 conductor phone wire that has tinsel wire and is extremely thin, soft and pliable. I have subbed them for the normal wire leads between the tube output connectors and the double stack assy. input terminals. The scale settles down quickly and the "creep" up and down as the original wires relaxed is almost gone. With this mod I recorded a 114 milligram weight increase using 1 KV as tube supply. This I have cut down by 50% to 57 milligrams, as the actuator arm that rests on the scale is extended from the central pivot point, and sticks out half the distance of the arm ends where the stacks are positioned, so there is some force gain by lever action. I chose the central point to mount the actuator arm as the vibrations coming down the arms hopefully will cancel out in the center. Since some vibrations must still be coming through, or even enhanced by this setup, I put in a 1/8" felt pad between the arm and the scale and read a more reasonable 6 milligram weight gain.
  23. I have seen that the highest useable voltage is 3KV, when I heard the arc snap within the stack. I backed up the voltage to just below that and did more scale tests, the results were not much, if any higher than with 1.5KV. This is disappointing as a member of the woodward team was indicating that Kaluza Kline infers an interaction that increases at the 4th power of the voltage. I have yet to hook up the end piezos on the two stacks on the arm, only am relying on the readout from the primary stack, which does certainly give access to how to proceed, but I need the two matrixed end piezos of both stacks driving another dual trace scope. I will switch between scope inputs for now, so as to do another torque test on both arm stacks and try to equalize their individual responses.
  24. I am very happy to report that due to a simple loose connection in the HV supply, the chattering noise has been removed. This seems to mean that the neon sign noise is once again the result of the tubes, or largely so and I don't have to rewire the supply. The transformer has a nice smooth hum now, so I increased the voltage output to 2.5KV for a brief period and got a stable 11 milligrams of weight increase. I can turn off the weight gain by several means. I can simply shut down the generator, alter the delay timing, drive frequency or shut down the HV supply. The question remains for now if the readings indicate a real weight change from thrust or from simple scale vibrations. Only when I do a balanced arm test that shows actual movement can that be settled. I seems likely that scale indications are partly due to simple vibrations, but if there is a real thrust appearing, it is imbedded within it, and of a certain percentage of a given reading. Part of my problem is that the scale shuts down after a few minutes automatically, and i have remove the lever arm from the scale and start over, and the scale takes about a full minute to stabilize to the tare weight of the slightly overbalanced arm, which is about 6 milligrams. This gives me a limited time to do a particular test in most cases, but sometimes the scale "forgets" to shut down, but I don't think there is a way to make it do so. I do have the scale with the wired remote on/off button mod that allows me to activate it without touching the scale itself, which is quite a help, as pressing the button on the scale is itself a major source of arm jitter.
  25. tonight I hooked up the entire tube driven assembly and had some encouraging results. I got a reliable weight increase of 3-5 milligrams with occasional readings of +7-8. This is nothing new, as I got similar results with the SS unit with it's 600V supply over a year ago, however the shortcomings of the neon transformer are becoming apparent, as if I increase the supply volts to the tube plates much over 600V, the noise level and chattering that comes from the transformer becomes excessive. Even the piezos mimic the sound and do so even with the drive signal to them turned off. Apparently the current control circuit within the transformer is the cause, and makes that neon sign noise that I had always attributed to the neon tubes themselves. I will rewire the power supply to remove the noise on the high voltage line and hopefully will smooth out the supply and can continue on with the high voltage tests. Sorry about the underlining, but can't get that function to shut off. 't v, the transformer get noisy and that noise is reflected into the tandem piezo units even with no inputs, causing me to remember the noise an old school neon sign made, having been around them in store windows and the like years ago. I had surmised that the noise was from the neon tubes themselves, and it seems that the transformer current regulator circuit is the cause. The transformer and piezos chatter away sounding just like a standard neon sign. A conversion of the power supply is in order to eliminate the buzz in the DC supply, and increase the current capability, note...disregard the second paragraph, it turned blue and disappeared after writing it, so I had to re write it and the underlining got stuck on, then the lost paragraph reappearerd when submitting the reply, but doesn't show up in the edit function, so I can't remove it.
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