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hoola

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Posts posted by hoola

  1. the new 4017 and phase inverter boards are installed and working correctly. The power drive module is completed and affixed to the balance arm support structure, but have not powered it up yet, as the arm is still being rebuilt and I don't want to run the module unloaded. Each piezo end will be independently driven and without the common ground, so ten wires per side. I am using the previous arrangement of the two stacks mounted at arm ends, inverted from one another and being run in parallel. The double HV supply is completed and working well.

  2. the dual power supply idea seems more promising as I have been occasionally placing high value resistors across the test stack inputs to gauge the approximate P-P voltage. Up till now a rather weak 1/8" or so of arcing was seen. Upon completing the biasing and drive level adjustments of the phase inverter circuit,  running at 125khz, the test resistor exploded, then the remnants burned and smoked. I see this as a positive sign overall, but may be nearing the limits that the particular piezos i have been using can operate at.

  3. while in the process of building the phase inverter module, a new 4017 board is also being built. All signal processing and control of the main 125 khz signal originating from the wavetek generator will be in one chassis, which will feed a second  chassis containing the output transistors and related power resistors, itself driven by the dual power supply. The balance arm will be shorter than before, with an overall length of 8" or so as to fit inside a minimum sized vacuum chamber containing the arm only, hooked up by gas tight feed-through capacitors from the driver chassis. If I achieve what appears to be thrust for a second sustained time, the vacuum chamber will be evacuated to falsify or show evidence of any success of the concept.

  4.  I have considered that a double power supply of both + and -  might prove advantageous. The positive one drives a conventional setup to one side of the stack, with corresponding output transistor from the negative supply driving the other end of the stack. This could deliver a AC signal pulse of an increased voltage as is delivered by the single positive supply only, to it's simple ground reference. Initial tests of the this system seems promising, having used a phase splitter to run a push-pull type drive to the two output transistors. If this system continues to give promise, I will forgo the transformer work for the present and continue to build up the double supply idea. This will require 2 output transistors per channel with an associated phase splitter. The common ground of the stack will have to be eliminated and each piezo will be driven independently by two outputs. This hopefully allow the actual driven signal to  each element to meet or exceed 1200v p-p while keeping the individual output transistors below their 800v p-p limitation. Each driving signal is no larger than a single transistor's output, but due to being driven in overall phase additive, by opposing voltage supplies, there should be a significant additive effect. ideally, a PNP complement of the nte 165 might be used, but there seems no high voltage PNP transistors readily available (hence the need for a phase splitter), so I have used a conventional nte165, by putting the negative supply on the emitter, with the collector to ground with the standard size load resistor of 100k, which seems to work fine in today's inital hookup.

  5. Having finished all five transformers, they do stimulate the elements about as well as one would expect, and of inadequate levels.  Given their small size they quickly saturate under load, so I have gone back to direct stimulation from the transistors. I will increase the supply voltage to them from the 700v now used in increments to see how much voltage they can safely handle. In the meantime I am researching transformer winding techniques and will acquire ferrite cores and .1mm wire and begin test winds. I will inquire with the seller on the potted tranformers  to see if  he could request the manufacturer supply the same transformers without completing the final potting step.

  6. i must have hit it way lucky with my first try to wind a new primary, as primary #2 one was rather weak in  response test, not responding until driven over 200K.  The #1 primary weighs exactly 3milligrams  (including bobbin which weighs .367 milligrams) with the scotch tape holding the winding to the core. I swapped the #1 primary onto the core and secondary of the #2 transformer, and the results were still positive, eliminating the core or secondary as a failure point on the #2 primary. The #2 primary weighed 3.21 milligrams, so I trimmed off about 5' of wire and got a reading of just under 3 milligrams without the tape. Amazingly, this slight removal of wire has made the installed  #2 primary almost identical to #1 in response in the sweet spot of the  100-200K range.The quick resolve of the problem may have more to do than simple weight (using that as a measure of overall length) such as layering techniques and steadyness of tension, but I appear to have 2 functioning transformers so far.

  7. today I went back to the little transformers and decided to utilize the fact that they are easy to take apart and did so. I removed the primary bobbin and took out the windings, of which there are two in parallel, each only about 3 1/2' long. A second primary winding was of lighter gauge and was used for a feedback line to the spark generator kit the transformer was designed for. I unwrapped a light enamel wire from a small AC motor field coil and wound a single primary of about 40' in length, all I could fit onto the small bobbin and be able to fit it back into the ferrite core. The results are promising, having a good secondary output response throughout the range required and seems to have a good enough input impedance match. I will proceed to re-wind four more of the minis and use them for the next series of tests. The measured DC  resistance of the new primary is 3.9 ohms.

  8. today I got in the new 10KV transformers and it began with seeing that they were encased in a hard clear thick epoxy, preventing me from altering them in the manner I had considered. They need a large (.47mfd) capacitor across the primary to get any useful current to transfer through them, indicating a much too low primary winding impedance, but they are an improvement over the previous smaller ones. With the addition of the .47mfd cap, current transfer peaks at 170 KHZ, close to the needed range. I will begin to assemble the new system with those, continue to look online for a more suitable transformer, and will explore the idea of winding my own. 

  9. it does seem I was incorrect in my assessment of the reciprocal loss, as the pistons slow down at the end of travel, returning the start up energy. The fact that the engine is a closed system was the key....my idea that energy must be used to slow down the mass is from an open system, say a space craft in space needing to exert energy to slow down. Thank you studiot and exchemist.

  10. with each stroke of a piston, the direction of travel changes 180'.   The piston stops and has to be re accelerated twice each time the crankshaft completes a single turn. The wankel design is flawed in that the seals are difficult to keep working and the main inefficiencies deal with things other than reciprocation losses, which is complicated by the poor emmisions a wankel inherently has.  There are youtube videos that describe the extent of these reciprocation losses should you wish to find a more detailed explanation.

  11. While the efficiency loss due to the reciprocation of the pistons in an typical automobile  engine are well known, what if the engine were mounted horizontally, and laid flat with it's pistons arranged to move fore and aft and in alignment to the direction of the vehicle?  Would the inertial mass of the pistons/rocker arms moving backwards, and now in alignment with the vehicle motion, cause a slight gain in overall velocity to the vehicle due to simple momentum transfer? While the return piston travel would cancel out any forward velocity gain, would that not essentially remove the reciprocation losses as  found in a normally mounted engine, with the piston travels not in alignment with vehicular motion? in this case the engine would have to be an inline, as in a simple in line four cylinder, with no modifications other than the mounting change.

  12. I found a 10KV high frequency transformer online that is three times the size and has 6 separated windings for the secondary that have dividers between them, so that the wire loops up over the dividers, allowing me to cut the line between the two middle secs and rewire for two 5KV secondaries in parallel with the additional current. The nomenclature involved does not identify it well, only listed on ebay as " 10KV transformation ratio 60 high-frequency coil transformer" There is an ID# but a google search showed nothing. They should be in in a week or two. Meanwhile I have built up a test breadboard for getting the impedance match as close as possible with the nte 165 drives. I will use a emitter follower circuit at first as that seems the best transfer using the smaller ones as a guide. The smaller ones are somewhat amusing in that they are literally held together with scotch tape, yet work fairly well, and can develop a considerable arc.

  13. I got the arc transformers in and they are smaller than pictured, being not much larger than your thumb, but do seem useable for the next series of testing.  At some point I will build another 4017 driver assy, and an oscillator on two small project boards and dispense with the now year old driver unit which has the original 4017 board and the wavetek 182 oscillator, which are both large and cumbersome, and have all controls, components and power supply on one open breadboard other than the piezo stacks and their support structure.

  14. would a capacitor made of superconducting materials pass a signal with any obvious difference from a normal one? And does the measured inductance of a room temp metal change if it's temp is lowered to superconduction?

  15. I have decided to not test again past the initial negative test as I have no further information as of yet as to the poling polarity used, so as to not potentially damage the new stacks, will wait until the SS driver unit is ready to proceed.

  16. while initial tests with the new stacks are negative, some odd things need attention before a good outcome might be achieved. The first was a lost ground to the left side stack, and upon checking, no problem could be found and no reason for an intermittent to have happened, and now indicates correctly. The next issue is with peaking out the new stacks.  Neither have a definitive sweet spot show up on the scope as with all previous stacks, but I can hear the increase/decrease as the spot is neared, which is inadequate and must be addressed. I have ordered 3 NOS tubes and the high frequency transformers that should be here this week. I will address current technical problems at hand and  replace the weaker  tubes before giving up on the tube drive idea for a while.  I am drawing up a schematic for a solid state final drive module using five nte 165 transistors driving five high frequency transformers while using the same interface module output DIN socket , so a swap out from the tube final drive with an SS final should be easy. I am aware now that the elements are "poled", that is, given a domain preference similar to lining up domains in a magnet, and that poling is accomplished with an electric field. I have no idea if the DC that my signal rides upon is in accord with the initial poling polarity during manufacturing, or I am counter to that orientation and am scrambling the domain structure more each time I turn it on. With the transformer drive, only the AC signal will be present, eliminating that as a possible issue. I will send steminc an email and request what polarity and voltage is used in poling my particular elements. The piezos all have a red line on the side near the top of each disc. I face all red marked elements up in accordance to that to keep them in phase. Traditionally, the red mark is denoted as the positive input to a device, and hopefully that is also used in the poling process.

  17.  hu??, I did not see your entry last nite when I described the weight issue. Thank you so much and I will  check out that webpage today. This is perhaps a good thing, as the piezos are 5.5mm thick, so perhaps are useful for the 3KV DC across them. I must see what is meant with polarizable and reverse polarizable terms in relation to the rings. I will have both stacks done today, designated as 2.1 and 3.1 and proceed with tests keeping the HV down below what seems prudent with the new info from the webpage you listed. I have not researched piezo properties specifics, but it is certainly time to do so.

    a quick readthrough of the webpage is rather daunting, and shows how subtle the processes are that take place in construction, with many new terms used in controlling applications. The most obvious term that applies to my situation is "creep" wherein a piezo loses some displacement over time. I will know today if a simple replacement of the elements will restore the desired responses noted last month.

  18. today I received the 16 new piezos and began replacing the #3 stack elements. Upon removing them I thought I noticed a difference in the weights of some of them. Upon checking, the end piezos, that didn't have a voltage applied to them as they were passives, weighed slightly more than the five active ones. The weights of the passives were 33.712 and 33.727 grams.  The five actives were all slightly less. I will not give the first two digits, as they are all 33. The weights are .684, .704, .545, .532, .676. I will rebuild the stack and record each weight for further reference. It is too much to imagine that the lost weights indicate a loss of mass, that was converted into thrust energy, but it is an amusing thought. Almost certainly the heavier ones randomly got placed on the ends, but weight is a parameter I need to start keeping track of to falsify any conjectures along that line. Upon weighing a random sample of the new ones, I got.....(33)  .919, .765, .780, .707,  .632,  ,620,  ,591 so a rather wide range of values that likely accounts for the differentials in the #3 stack.  After rebuilding, this stack will be designated as stack 3.1

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